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Special Senses and Chemical Communication

(The following additional keywords have been used to categorize articles within this section and may assist your search.)

cataract, chemical communication, cognition, communication, ear mite, eye, infrasound, intelligence, pheromones, seismic, special senses, vision, vocalization

Elephant Bibliographic Database
www.elephantcare.org

References updated October 2009 by date of publication, most recent first.

Bates, L.A., Lee, P.C., Njiraini, N., Poole, J.H., Sayialel, K., Moss, C.J., Byrne, R., 2009. Do elephants show empathy? JOURNAL OF CONSCIOUSNESS STUDIES 15, 204-225.
Abstract:
Elephants show a rich social organization and display a number of unusual traits. In this paper, we analyse reports collected over a thirty-five year period, describing behaviour that has the potential to reveal signs of empathic understanding. These include coalition formation, the offering of protection and comfort to others, retrieving and 'babysitting' calves, aiding individuals that would otherwise have difficulty in moving, and removing foreign objects attached to others. These records demonstrate that an elephant is capable of diagnosing animacy and goal directedness, and is able to understand the physical competence, emotional state and intentions of others, when they differ from its own. We argue that an empathic understanding of others is the simplest explanation of these abilities, and discuss reasons why elephants appear to show empathy more than other non-primate species.

Glaeser, S.G., Klinck, H., Mellinger, D.K., Ren, Y., 2009. A vocal repertoire of Asian elephants (Elephas maximus) and comparison of call classification methods. J Acoust Soc Am 125, 2710.
Abstract:
This study compares classification methods applied to an acoustic repertoire of the Asian elephant (Elephas maximus). Recordings were made of captive elephants at the Oregon Zoo in Portland, OR and of domesticated elephants in Thailand. Acoustic and behavioral data were collected in a variety of social contexts and environmental noise conditions. Calls were classified using three methods. First, calls were classified manually using perceptual aural cues plus visual inspection of spectrograms for differentiation of fundamental frequency contour, tonality, and duration. Second, a set of 29 acoustic features was measured for nonoverlapping calls using the MATLAB-based program Osprey, then principal component analysis was applied to reduce the feature set. A neural network was used for classification. Finally, hidden Markov models, commonly used for pattern recognition, were utilized to recognize call types using perceptually-weighted cepstral features as input. All manual and automated classification methods agreed on structural distinction of six basic call types (trumpets, squeaks, squeals, roars, rumbles, and barks), with two call types (squeaks and squeals) being highly variable. Given the consistency of results among the classification methods across geographically and socially disparate subject groups, we believe automated call detection could successfully be applied to acoustic monitoring of Asian elephants.

Grus, W.E., Zhang, J., 2009. Origin of the genetic components of the vomeronasal system in the common ancestor of all extant vertebrates. Molecular Biology and Evolution 26, 407-419.
Abstract: Comparative genomics provides a valuable tool for inferring the evolutionary history of physiological systems, particularly when this information is difficult to ascertain by morphological traits. One such example is the vomeronasal system (VNS), a vertebrate nasal chemosensory system that is responsible for detecting intraspecific pheromonal cues as well as environmental odorants. The morphological components of the VNS are found only in tetrapods, but the genetic components of the system have been found in teleost fish, in addition to tetrapods. To determine when the genetic components of the VNS originated, we searched for the VNS-specific genes in the genomes of two early diverging vertebrate lineages: the sea lamprey from jawless fishes and the elephant shark from cartilaginous fishes. Genes encoding vomeronasal type 1 receptors (V1Rs) and Trpc2, two components of the vomeronasal signaling pathway, are present in the sea lamprey genome, and both are expressed in the olfactory organ, revealing that the genetic components of the present-day VNS existed in the common ancestor of all extant vertebrates. Additionally, all three VNS genes, Trpc2, V1Rs, and vomeronasal type 2 receptors (V2Rs), are found in the elephant shark genome. Because V1Rs and V2Rs are related to two families of taste receptors, we also searched the early diverging vertebrate genomes for taste system genes and found them in the shark genome but not in the lamprey. Coupled with known distributions of the genetic components of the vertebrate main olfactory system, our results suggest staggered origins of vertebrate sensory systems. These findings are important for understanding the evolution of vertebrate sensory systems and illustrate the utility of the genome sequences of early diverging vertebrates for uncovering the evolution of vertebrate-specific traits

Haakonsson, J.E., Semple, S., 2009. Lateralisation of trunk movements in captive Asian elephants (Elephas maximus)
112. Laterality. 14, 413-422.
Abstract: Behavioural lateralisation has been widely investigated in vertebrates. Most studies in this area have focused on laterality in paired organs such as hands, limbs, and eyes. Fewer studies have explored side preferences in unpaired organs such as tails or trunks. We investigated laterality of trunk use among captive Asian elephants (Elephas maximus), quantifying side preference in four different trunk movements: feeding, sand spraying, self-touching, and swinging. We found evidence for significant side preference in all four movement categories. Variation in the occurrence and direction of side preference was seen both within and between individuals but no overall population-level side bias was seen for any of the four trunk movements. The strength of side preference in trunk use was significantly higher for feeding than for self-touching and swinging. This study adds to the very limited data on laterality in unpaired organs generally, and elephants' trunks more specifically. In addition it provides novel information about directional lateralisation in trunk use across a range of functionally distinct contexts

Irie-Sugimoto, N., Kobayashi, T., Sato, T., Hasegawa, T., 2009. Relative quantity judgment by Asian elephants (Elephas maximus). Anim Cogn 12, 193-199.
Abstract: This study investigated whether Asian elephants can make relative quantity judgment (RQJ), a dichotomous judgment of unequal quantities ordered in magnitude. In Experiment 1, elephants were simultaneously shown two baskets with differing quantities of bait (up to 6 items). In Experiment 2, elephants were sequentially presented with baits, which could not be seen by elephants in their total quantities. The task of elephants was to choose the larger quantity in both experiments. Results showed that the elephants chose the larger quantity with significantly greater frequency. Interestingly, the elephants did not exhibit disparity or magnitude effects, in which performance declines with a smaller difference between quantities in a two-choice task, or the total quantity increases, respectively. These findings appear to be inconsistent with the previous reports of RQJ in other animals, suggesting that elephants may be using a different mechanism to compare and represent quantities than previously suggested for other species

Plotnik, J.M., de Waal, F.B., Moore, D., III, Reiss, D., 2009. Self-recognition in the Asian elephant and future directions for cognitive research with elephants in zoological settings
48. Zoo. Biol.
Abstract: The field of animal cognition has grown steadily for nearly four decades, but the primary focus has centered on easily kept lab animals of varying cognitive capacity, including rodents, birds and primates. Elephants (animals not easily kept in a laboratory) are generally thought of as highly social, cooperative, intelligent animals, yet few studies-with the exception of long-term behavioral field studies-have been conducted to directly support this assumption. In fact, there has been remarkably little cognitive research conducted on Asian (Elephas maximus) or African (Loxodonta africana or L. cyclotis) elephants. Here, we discuss the opportunity and rationale for conducting such research on elephants in zoological facilities, and review some of the recent developments in the field of elephant cognition, including our recent study on mirror self-recognition in E. maximus. Zoo Biol 28:1-13, 2009. (c) 2009 Wiley-Liss, Inc

Shyan-Norwalt, M.R., Peterson, J., Milankow, K.B., Staggs, T.E., Dale, R.H., 2009. Initial findings on visual acuity thresholds in an African elephant (Loxodonta africana). Zoo. Biol. 28, 1-6.
Abstract: There are only a few published examinations of elephant visual acuity. All involved Asian elephants (Elephas maximus) and found visual acuity to be between 8' and 11' of arc for a stimulus near the tip of the trunk, equivalent to a 0.50 cm gap, at a distance of about 2 m from the eyes. We predicted that African elephants (Loxodonta africana) would have similarly high visual acuity, necessary to facilitate eye-trunk coordination for feeding, drinking and social interactions. When tested on a discrimination task using Landolt-C stimuli, one African elephant cow demonstrated a visual acuity of 48' of arc. This represents the ability to discriminate a gap as small as 2.75 cm in a stimulus 196 cm from the eye. This single-subject study provides a preliminary estimate of the visual acuity of African elephants. Zoo Biol 28:1-6, 2009. (c) 2009 Wiley-Liss, Inc

Soltis, J., Leighty, K.A., Wesolek, C.M., Savage, A., 2009. The expression of affect in African elephant (Loxodonta africana) rumble vocalizations
59. J. Comp Psychol. 123, 222-225.
Abstract: Affective states are thought to be expressed in the mammalian voice, but such investigations are most common in primates. Source and filter features of rumbles were analyzed from 6 adult female African elephants (Loxodonta africana) at Disney's Animal Kingdom. Rumbles produced during periods of minimal social interaction ("low affect") were compared to those produced during dominance interactions ("high affect"). Low-ranking females produced rumbles with increased and more variable fundamental frequencies, and increased durations and amplitudes during dominance interactions with superiors, compared to the low affect context. This acoustic response is consistent with the expression of affect in mammals and may signal submission to superiors. The 2 highest ranking females were codominant and competed for alpha status. They produced rumbles with decreased and less variable fundamental frequencies, increased durations and amplitudes, and a decrease in formant dispersion during dominance interactions with each other, compared to the low affect context. This response is not generally consistent with the expression of affect, but may signal large body size to competitors. These results suggest that affect can be expressed in the voiced sounds of elephants

Soltis, J., 2009. Vocal communication in African Elephants (Loxodonta africana)
61. Zoo. Biol. 28, 1-18.
Abstract: Research on vocal communication in African elephants has increased in recent years, both in the wild and in captivity, providing an opportunity to present a comprehensive review of research related to their vocal behavior. Current data indicate that the vocal repertoire consists of perhaps nine acoustically distinct call types, "rumbles" being the most common and acoustically variable. Large vocal production anatomy is responsible for the low-frequency nature of rumbles, with fundamental frequencies in the infrasonic range. Additionally, resonant frequencies of rumbles implicate the trunk in addition to the oral cavity in shaping the acoustic structure of rumbles. Long-distance communication is thought possible because low-frequency sounds propagate more faithfully than high-frequency sounds, and elephants respond to rumbles at distances of up to 2.5 km. Elephant ear anatomy appears designed for detecting low frequencies, and experiments demonstrate that elephants can detect infrasonic tones and discriminate small frequency differences. Two vocal communication functions in the African elephant now have reasonable empirical support. First, closely bonded but spatially separated females engage in rumble exchanges, or "contact calls," that function to coordinate movement or reunite animals. Second, both males and females produce "mate attraction" rumbles that may advertise reproductive states to the opposite sex. Additionally, there is evidence that the structural variation in rumbles reflects the individual identity, reproductive state, and emotional state of callers. Growth in knowledge about the communication system of the African elephant has occurred from a rich combination of research on wild elephants in national parks and captive elephants in zoological parks. Zoo Biol 28:1-18, 2009. (c) 2009 Wiley-Liss, Inc

Thitaram, C., Chansitthiwet, S., Pongsopawijit, P., Brown, J.L., Wongkalasin, W., Daram, P., Roongsri, R., Kalmapijit, A., Mahasawangkul, S., Rojanasthien, S., Colenbrander, B., van der Weijden, G.C., van Eerdenburg, F.J., 2009. Use of genital inspection and female urine tests to detect oestrus in captive Asian elephants
116. Anim Reprod. Sci. 115, 267-278.
Abstract: Captive Asian elephant (Elephas maximus) populations are decreasing due to low birth rates compared to wild elephants. Improving oestrous detection in female elephants is required to ensure successful mating in captive and semi-captive herds. Responsive behaviours of eight semi-captive bull elephants to the uro-genital area (genital inspection test) or urinary pheromones (urine test) of 14 female elephants throughout the oestrous cycle were evaluated. Weekly blood samples were collected for 27 consecutive months (14 months for the genital inspection test and 13 months for the urine test) from female elephants to characterize the patterns of circulating progestagen. Responsive behaviours of bulls were compared between females in the follicular versus the luteal phase of the cycle. The sensitivity and specificity of the genital inspection test were 65% and 68%, while those of the urine test were 52% and 61%, respectively. The bulls showed significantly higher "genital inspection", "flehmen from genital area" and "trunk on back" behaviours during the genital inspection test, and "flehmen" behaviours during the urine test in oestrous than in non-oestrous females. In sum, this study showed that monitoring sexual behaviours of Asian elephant bulls towards females or their urine can be used to detect the oestrous period. Although the sensitivity and specificity of both tests were not as high as expected, still, these methods appear to be more efficient at detecting oestrous than traditional methods based on mahout estimations of female receptivity. The use of genital inspection and urine tests may lead to more successful matings and thus to creating self-sustaining populations of captive elephants in range countries

Thompson, M.E., Schwager, S.J., Payne, K.B., Turkalo, A.K., 2009. Acoustic estimation of wildlife abundance: methodology for vocal mammals in forested habitats. African Journal of Ecology.
Abstract:
Habitat loss and hunting pressure threaten mammal populations worldwide, generating critical time constraints on trend assessment. This study introduces a new survey method that samples continuously and non-invasively over long time periods, obtaining estimates of abundance from vocalization rates. We present feasibility assessment methods for acoustic surveys and develop equations for estimating population size. As an illustration, we demonstrate the feasibility of acoustic surveys for African forest elephants (Loxodonta africana cyclotis). Visual surveys and vocalizations from a forest clearing in the Central African Republic were used to establish that low-frequency elephant calling rate is a useful index of elephant numbers (linear regressionP<0.001,radj.2=0.58). The effective sampling area was 3.22km2per acoustic sensor, a dramatic increase in coverage over dung survey transects. These results support the use of acoustic surveys for estimating elephant abundance over large remote areas and in diverse habitats, using a distributed network of acoustic sensors. The abundance estimation methods presented can be applied in surveys of any species for which an acoustic abundance index and detection function have been established. This acoustic survey technique provides an opportunity to improve management and conservation of many acoustically-active taxa whose populations are currently under-monitored.

Thompson, M.E., Schwager, S.J., Payne, K.B., 2009. Heard but not seen: an acoustic survey of the African forest elephant population at Kakum Conservation Area, Ghana. African Journal of Ecology.
Abstract:
This study, designed to survey forest elephants (Loxodonta africana cyclotis) at Kakum Conservation Area, Ghana, is the first to apply acoustic methods to elephant abundance estimation and to compare results with independent survey estimates. Nine acoustic sensors gathered sound continuously for 38days. Low-frequency calling rates have been established as useful elephant abundance indices at a Namibian watering hole and a central African forest clearing. In this study, we estimated elephant population size by applying an abundance index model and detection function developed in central Africa to data from simultaneous sampling periods on Kakum sensors. The sensor array recorded an average of 1.81 calls per 20-min sampling period from an effective detection area averaging 10.27km2. The resulting estimate of 294 elephants (95% CI: 259-329) falls within confidence bounds of recent dung-based surveys. An extended acoustic model, estimating the frequency with which elephants are silent when present, yields an estimate of 350 elephants (95% CI: 315-384). Acoustic survey confidence intervals are at least half as wide as those from dung-based surveys. This study demonstrates that acoustic surveying is a valuable tool for estimating elephant abundance, as well as for detecting other vocal species and anthropogenic noises that may be associated with poaching.

Wesolek, C.M., Soltis, J., Leighty, K.A., Savage, A., 2009. Infant African elephan rumble vocalizations vary according to social interactions with adult females. Bioacoustics 18, 227-239.
Abstract:
Research on African elephant (Loxodonta africana) vocal communication has increased in recent years, yet there has been very little data collected on the vocal production of infant African elephants. Vocalizations were recorded from a group of five adult female African elephants and 3 dependent offspring (1 male and 2 female) at Disney's Animal Kingdom, Florida, U.S.A., using custom-designed audio-recording collars worn by the adult females. We measured both source and filter features of infant 'rumble' vocalizations made during affiliative social interactions and after cessation of nursing from adult females. Rumble vocalizations produced in the 'nurse cessation' context exhibited an upward shift in formant frequency locations, compared to rumbles produced during the 'affiliation' context. Additionally, call duration increased and fundamental frequencies decreased after nurse cessations for the male, but both females showed the opposite acoustic response. When infant rumbles accompanied nurse cessations, nursing was more likely to resume within 30 seconds compared to nurse cessations without vocalizations. These results suggest that infant rumbles associated with cessation of nursing reflect the motivational state of infants and may influence maternal responsiveness.

Bates, L.A., Poole, J.H., Byrne, R.W., 2008. Elephant cognition. Curr. Biol. 18, R544-R546.

Hollister-Smith, J.A., Alberts, S.C., Rasmussen, L.E.L., 2008. Do male African elephants, Loxodonta africana, signal musth via urine dribbling? Animal Behavior 76, 1829-1841.
Abstract:
The phenomenon of musth in male elephants involves increased sexual activity, heightened aggression and nearly continuous dribbling of pungent smelling urine. Urine chemistry during musth is altered, suggesting that urine may signal the musth status of the individual. Signalling musth remotely may benefit individuals if it reduces the likelihood of physical confrontation between males, which can lead to injury and even death. Few studies, however, have asked whether and how male elephants respond to urine of other males. We tested two predictions of the hypothesis that urine signals musth status to male conspecifics: (1) that male African elephants differentiate musth and nonmusth urine, and (2) that males differentiate between urine dribbled during early and late musth. The second prediction stems from the observation that males lose weight and presumably body condition during musth. We conducted two related bioassays with 26 captive nonmusth males ranging from 13 to 52 years of age. In each assay, subjects were simultaneously presented with three urine samples (nonmusth, early musth, late musth), each from a different donor male, and a control. We found that subjects differentiated between musth and nonmusth samples using their vomeronasal organ system, but did not discriminate between the samples using their main olfactory system. Males did not differentiate early from late musth. In addition, we found that subject contextual factors, specifically age, dominance status and social grouping, significantly predicted response. We discuss these results within the framework of male elephant longevity and social relationships and their importance to reproductive success.

Meyer, J., Goodwin, T., Schulte, B., 2008. Intrasexual chemical communication and social responses ofcaptive female African elephants. Animal Behavior 76, 163-174.
Abstract:
In matrilineal societies, competition between females can occur within and between social units. Dominance hierarchies reduce costly conflicts when reliable cues of status are available, and reproductive condition may alter individual or group status. Female African elephants live in matriarchal groups with linear dominance hierarchies occurring within and between groups; elephants use chemical signals to mediate social interactions. If reproductive condition has important implications for inter- or intragroup behaviour, then females should discriminate between chemical signal sources that reveal reproductive condition. We examined whether trunk-tip contacts between females within a social group were related to phase of oestrus. Observations were conducted on 21 reproductively viable females at nine zoological facilities in North America. Females in the follicular phase received contacts to the urogenital region at a higher rate than did luteal phase females, and contacts increased with approaching ovulation. This supports the existence of an oestrous signal. We also examined whether an oestrous signal was evident by female investigation of urine collected from the luteal and follicular phases of unfamiliar conspecifics. Elephants responded to unfamiliar urine more than to the control, but response rates to the urine types did not differ. Females within a social unit detected differences in oestrus, but they did not show such discrimination to urinary signals from unfamiliar females. Further evaluation of the existence of a female-to-female oestrous pheromone requires assessing responses to urine from familiar individuals. Understanding the relationship between oestrous condition and dominance status can shed light on the adaptive value of sociality.

Nicholls, H., 2008. Darwin 200: Let's make a mammoth. Nature 456, 310-314.

Tyack, P.L., 2008. Convergence of calls as animals form social bonds, active compensation for noisy communication channels, and the evolution of vocal learning in mammals. J. Comp Psychol. 122, 319-331.
Abstract: The classic evidence for vocal production learning involves imitation of novel, often anthropogenic sounds. Among mammals, this has been reported for dolphins, elephants, harbor seals, and humans. A broader taxonomic distribution has been reported for vocal convergence, where the acoustic properties of calls from different individuals converge when they are housed together in captivity or form social bonds in the wild. Vocal convergence has been demonstrated for animals as diverse as songbirds, parakeets, hummingbirds, bats, elephants, cetaceans, and primates. For most species, call convergence is thought to reflect a group-distinctive identifier, with shared calls reflecting and strengthening social bonds. A ubiquitous function for vocal production learning that is starting to receive attention involves modifying signals to improve communication in a noisy channel. Pooling data on vocal imitation, vocal convergence, and compensation for noise suggests a wider taxonomic distribution of vocal production learning among mammals than has been generally appreciated. The wide taxonomic distribution of this evidence for vocal production learning suggests that perhaps more of the neural underpinnings for vocal production learning are in place in mammals than is usually recognized

Bates, L.A., Sayialel, K.N., Nijiraini, N.W., Moss, C.J., Poole, J.H., Byrne, R.W., 2007. Elephants classify human ethnic groups by odor and garment color. Current Biology 17, 1-5.
Abstract:
PrFont34Bin0BinSub0Frac0Def1Margin0Margin0Jc1Indent1440Lim0Lim1Animals can benefit from classifying predators or other dangers into categories, tailoring their escape strategies to the type and nature of the risk. Studies of alarm vocalizations have revealed various levels of sophistication in classification [1-5]. In many taxa, reactions to danger are inflexible, but some species can learn the level of threat presented by the local population of a predator [6-8] or by specific, recognizable individuals [9, 10]. Some species distinguish several species of predator, giving differentiated warning calls and escape reactions; here, we explore an animal's classification of subgroups within a species. We show that elephants distinguish at least two Kenyan ethnic groups and can identify them by olfactory and color cues independently. In the Amboseli ecosystem, Kenya, young Maasai men demonstrate virility by spearing elephants (Loxodonta africana), but Kamba agriculturalists pose little threat. Elephants showed greater fear when they detected the scent of garments previously worn by Maasai than by Kamba men, and they reacted aggressively to the color associated with Maasai. Elephants are therefore able to classify members of a single species into subgroups that pose different degrees of danger.

Bates, L.A., Byrne, R.W., 2007. Creative or created: using anecdotes to investigate animal cognition. Methods 42, 12-21.
Abstract: In non-human animals, creative behaviour occurs spontaneously only at low frequencies, so is typically missed by standardised observational methods. Experimental approaches have tended to rely overly on paradigms from child development or adult human cognition, which may be inappropriate for species that inhabit very different perceptual worlds and possess quite different motor capacities than humans. The analysis of anecdotes offers a solution to this impasse, provided certain conditions are met. To be reliable, anecdotes must be recorded immediately after observation, and only the records of scientists experienced with the species and the individuals concerned should be used. Even then, interpretation of a single record is always ambiguous, and analysis is feasible only when collation of multiple records shows that a behaviour pattern occurs repeatedly under similar circumstances. This approach has been used successfully to study a number of creative capacities of animals: the distribution, nature and neural correlates of deception across the primate order; the occurrence of teaching in animals; and the neural correlates of several aptitudes--in birds, foraging innovation, and in primates, innovation, social learning and tool-use. Drawing on these approaches, we describe the use of this method to investigate a new problem, the cognition of the African elephant, a species whose sheer size and evolutionary distance from humans renders the conventional methods of comparative psychology of little use. The aim is both to chart the creative cognitive capacities of this species, and to devise appropriate experimental methods to confirm and extend previous findings

Bates, L.W., Byrne, R.W., 2007. Creative or created: Using anecdotes to investigate animal cognition. Methods 42, 12-21.
Abstract: In non-human animals, creative behaviour occurs spontaneously only at low frequencies, so is typically missed by standardised observational methods. Experimental approaches have tended to rely overly on paradigms from child development or adult human cognition, which may be inappropriate for species that inhabit very different perceptual worlds and possess quite different motor capacities than humans. The analysis of anecdotes offers a solution to this impasse, provided certain conditions are met. To be reliable, anecdotes must be recorded immediately after observation, and only the records of scientists experienced with the species and the individuals concerned should be used. Even then, interpretation of a single record is always ambiguous, and analysis is feasible only when collation of multiple records shows that a behaviour pattern occurs repeatedly under similar circumstances. This approach has been used successfully to study a number of creative capacities of animals: the distribution, nature and neural correlates of deception across the primate order; the occurrence of teaching in animals; and the neural correlates of several aptitudes-in birds, foraging innovation, and in primates, innovation, social learning and tool-use. Drawing on these approaches, we describe the use of this method to investigate a new problem, the cognition of the African elephant, a species whose sheer size and evolutionary distance from humans renders the conventional methods of comparative psychology of little use. The aim is both to chart the creative cognitive capacities of this species, and to devise appropriate experimental methods to confirm and extend previous findings.

Bouley, D.M., Alarcón, C.N., Hildebrandt, T., O'connell-Rodwell, C.E., ., 2007. The distribution, density and three-dimensional histomorphology of Pacinian corpuscles in the foot of the Asian elephant (Elephas maximus) and their potential role in seismic communication. J Anat 211, 428-435.
Abstract: Both Asian (Elephas maximus) and African (Loxodonta africana) elephants produce low-frequency, high-amplitude rumbles that travel well through the ground as seismic waves, and field studies have shown that elephants may utilize these seismic signals as one form of communication. Unique elephant postures observed in field studies suggest that the elephants use their feet to 'listen' to these seismic signals, but the exact sensory mechanisms used by the elephant have never been characterized. The distribution, morphology and tissue density of Pacinian corpuscles, specialized mechanoreceptors, were studied in a forefoot and hindfoot of Asian elephants. Pacinian corpuscles were located in the dermis and distal digital cushion and were most densely localized to the anterior, posterior, medial and lateral region of each foot, with the highest numbers in the anterior region of the forefoot (52.19%) and the posterior region of the hindfoot (47.09%). Pacinian corpuscles were encapsulated, had a typical lamellar structure and were most often observed in large clusters. Three-dimensional reconstruction through serial sections of the dermis revealed that individual Pacinian corpuscles may be part of a cluster. By studying the distribution and density of these mechanoreceptors, we propose that Pacinian corpuscles are one possible anatomic mechanism used by elephants to detect seismic waves.

King, L.E., Douglas-Hamilton, I., Vollrath, F., 2007. African elephants run from the sound of disturbed bees. Current Biology 17, 832-833.
Abstract: Encroaching human development into former wildlife areas [1] is compressing African elephants into ever smaller home ranges, causing increased levels of human-elephant conflict [2]. African honeybees have been proposed as a possible deterrent to elephants [3]. We have performed a sound playback experiment to study this hypothesis. We found that a significant majority of elephants, in a sample of 18 well-known families and subgroups of varying sizes, reacted negatively - immediately walking or running away - when they heard the buzz of disturbed bees, while they ignored the control sound of natural white-noise. Whether the observed response was the result of individual conditioning or of learning by social facilitation remains to be established. Our study strongly supports the hypothesis that bees - and perhaps even their buzz alone - may be deployed to keep elephants at bay.

O'connell-Rodwell, C.E., Wood, J.D., Kinzley, C., Rodwell, T.C., Poole, J.H., Puria, S., 2007. Wild African elephants (Loxodonta africana) discriminate between familiar and unfamiliar conspecific seismic alarm calls. J Acoust Soc Am 122, 823-830.
Abstract: The ability to discriminate between call types and callers as well as more subtle information about the importance of a call has been documented in a range of species. This type of discrimination is also important in the vibrotactile environment for species that communicate via vibrations. It has recently been shown that African elephants (Loxodonta africana) can detect seismic cues, but it is not known whether they discriminate seismic information from noise. In a series of experiments, familiar and unfamiliar alarm calls were transmitted
seismically to wild African elephant family groups. Elephants respond significantly to the alarm calls of familiar herds (p=0.004) but not to the unfamiliar calls and two different controls, thus demonstrating the ability of elephants to discriminate subtle differences between seismic calls given in the same context. If elephants use the seismic environment to detect and discriminate between conspecific calls, based on the familiarity of the caller or some other physical property, they may be using the ground as a very sophisticated sounding  board.

O'Connell-Rodwell, C.E., 2007. Keeping an "ear" to the ground: seismic communication in elephants. Physiology (Bethesda) 287-294.
Abstract: This review explores the mechanisms that elephants may use to send and receive seismic signals from a physical, anatomical, behavioral, and physiological perspective. The implications of the use of the vibration sense as a multimodal signal will be discussed in light of the elephant's overall fitness and survival.

Savage, V.M., West, G.B., 2007. A quantitative, theoretical framework for understanding mammalian sleep. Proc. Natl. Acad. Sci. U. S. A 104, 1051-1056.
Abstract: Sleep is one of the most noticeable and widespread phenomena occurring in multicellular animals. Nevertheless, no consensus for a theory of its origins has emerged. In particular, no explicit, quantitative theory exists that elucidates or distinguishes between the myriad hypotheses proposed for sleep. Here, we develop a general, quantitative theory for mammalian sleep that relates many of its fundamental parameters to metabolic rate and body size. Several mechanisms suggested for the function of sleep can be placed in this framework, e.g., cellular repair of damage caused by metabolic processes as well as cortical reorganization to process sensory input. Our theory leads to predictions for sleep time, sleep cycle time, and rapid eye movement time as functions of body and brain mass, and it explains, for example, why mice sleep approximately 14 hours per day relative to the 3.5 hours per day that elephants sleep. Data for 96 species of mammals, spanning six orders of magnitude in body size, are consistent with these predictions and provide strong evidence that time scales for sleep are set by the brain's, not the whole-body, metabolic rate

Schulte, B.A., Freeman, E.W., Goodwin, T.E., Hollister-Smith, J., Rasmussen, L.E.L., 2007. Honest signalling through chemicals by elephants with applications for care and conservation. Applied Animal Behaviour Science 102, 344-363.
Abstract: Chemical signals are difficult to fake because they are often directly associated with phenotype and physiological condition, and hence likely to be honest signals for intraspecific communication. Chemical signals may be modified after release by the sender or by the environment. The proximate and ultimate signal meanings are dependent not only on the condition of the sender, but also on the physiological status of the receiver. Understanding the relationships and linkage among signal modality, signal function and receiver response is an essential first step before using natural signals for animal care and conservation. Our studies on chemical communication in Asian and African elephants combine observational and experimental work in captive and wild settings to further this understanding. Recent discoveries of pheromones in Asian elephants and the biochemistry of these compounds provide strong evidence that such chemical signals are honest indicators of reproductive status. Chemically identifying the signals and verifying their functional context with statistically robust behavioural studies are essential aspects for understanding the communication system. Additionally, the investigative process of discovering, identifying and verifying the function of chemical signals among captive elephants offers safe and stimulating enrichments. The knowledge garnered from such studies has potential conservation benefits for managing wild elephant populations. A firm foundation of scientific information is required for successful behavioural investigations and applied conservation and enrichment components.

Stoeger-Horwath, A.S., Stoeger, S., Schwammer, H.M., Kratochvil, H., 2007. Call repertoire of infant African elephants: first insights into the early vocal ontogeny. J. Acoust. Soc. Am. 121, 3922-3931.
Abstract: African savannah elephants (Loxodonta africana) have a complex acoustic communication system, but very little is known about their vocal ontogeny. A first approach in ontogenetic studies is to define the call repertoire of specific age groups. Twelve hundred calls of 11 infant elephants from neonatal to 18 months of age recorded at the Vienna Zoo in Austria and at the Daphne Sheldrick's orphanage at the Nairobi National Park, Kenya were analyzed. Six call types were structurally distinguished: the rumble, the bark, the grunt, the roar (subdivided into a noisy-, tonal-, and mixed-roar), the snort, and the trumpet. Generally, within-call-type variation was high in all individuals. In contrast to adult elephants, the infants showed no gender-dependent variation in the structure or in the number of call types produced. Male infants, however, were more vocally adamant in their suckle behavior than females. These results give a first insight to the early vocal ontogeny and should promote further ontogenetic studies on elephants. Due to their vocal learning ability in combination with the complex fission-fusion society, elephants could be an interesting model to study the role of imitation in the vocal ontogeny of a nonprimate terrestrial mammal

Teixeira, C.P., Schetini de Azevedo, C., Mendl, M., Cipreste, C.F., Young, R.J., 2007. Revisiting translocation and reintroduction programmes: the importance of considering stress. Animal Behaviour 73,  1-13.
Abstract: It is widely known that the adverse effects of stress must be considered in animal conservation programmes. However, a full consideration of how and where stress occurs in animal conservation programmes has not been undertaken, especially in translocation and reintroduction programmes. The literature concerning these types of programmes shows high levels of mortality, despite researchers' consideration of the effects of stress. However, an analysis of the literature shows that many conservation biologists have only a superficial knowledge about stress. For example, most do not understand the importance of subclinical stress or the fact that the effect of successive stressors can be additive or accumulative. While most conservation biologists know that stress is bad for animal health, few have considered its adverse effects on cognitive abilities, which an animal needs to survive in the wild (e.g. memory). In this paper we conclude with suggestions for improving the efficiency of animal conservation programmes in terms of the number of animals surviving after reintroduction or translocation. The most important conclusion from this review of the literature is that there needs to be a greater interchange of information between animal welfare and animal conservation scientists.

Bagley, K.R., Goodwin, T.E., Rasmussen, L.E.L., Schulte, B.A., 2006. Male African elephants, Loxodonta africana, can distinguish oestrous status via urinary signals. Animal Behaviour 71, 1445.
Abstract: African elephants are a polygynous species that raise offspring in a matriarchal society. Unlike females, males disperse, spend time in mate groups and search for mates when mature. Urinary chemical signals aid males in detecting reproductively active females. A preovulatory pheromone has been identified in Asian elephants, Elephas maximus, but has not yet been experimentally identified in African elephants. In this study, the goal was to determine whether adult captive male African elephants can distinguish between urine from conspecific females in luteal and periovulatory oestrous stages as an indication that a preovulatory pheromone is released in the urine. Urine was collected from seven different female African elephants during their luteal and periovulatory periods of oestrus. Bioassays were conducted with nine adult male elephants housed at six different facilities. Males were presented with the two urine types and a control sample once a day over 3 days to reduce sample novelty, which can result in misleadingly high responses. All mates showed greater chemosensory responses to the periovulatory urine by trial 3 with the ability to distinguish the urines increasing over the 3 days. This is the first experimental behavioural evidence that African elephants release an oestrous pheromone in the urine. The ability of the captive male elephants to discern between the two urine types bolsters the hypothesis that there is a preovulatory pheromone in African elephants and encourages efforts to identify it.

Clemins, P.J., Johnson, M.T., 2006. Generalized perceptual linear prediction features for animal vocalization analysis
431. J. Acoust. Soc. Am. 120, 527-534.
Abstract: A new feature extraction model, generalized perceptual linear prediction (gPLP), is developed to calculate a set of perceptually relevant features for digital signal analysis of animal vocalizations. The gPLP model is a generalized adaptation of the perceptual linear prediction model, popular in human speech processing, which incorporates perceptual information such as frequency warping and equal loudness normalization into the feature extraction process. Since such perceptual information is available for a number of animal species, this new approach integrates that information into a generalized model to extract perceptually relevant features for a particular species. To illustrate, qualitative and quantitative comparisons are made between the species-specific model, generalized perceptual linear prediction (gPLP), and the original PLP model using a set of vocalizations collected from captive African elephants (Loxodonta africana) and wild beluga whales (Delphinapterus leucas). The models that incorporate perceptional information outperform the original human-based models in both visualization and classification tasks

Dreisewerd, K., Kolbl, S., Peter-Katalinic, J., Berkenkamp, S., Pohlentz, G., 2006. Analysis of native milk oligosaccharides directly from thin-layer chromatography plates by matrix-assisted laser desorption/ionization orthogonal-time-of-flight mass spectrometry with a glycerol matrix
517. J. Am. Soc. Mass Spectrom. 17, 139-150.
Abstract: We have recently presented a new method for direct coupling of high-performance thin-layer chromatography (HPTLC) with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), illustrated by the analysis of a complex ganglioside mixture. In the current communication, an adaptation of this procedure to mixtures of native oligosaccharides from human and from elephant milk is described. The key features in this method are (1) glycerol as a liquid matrix, to provide a homogeneous wetting of the silica gel and a simple and fast MALDI preparation protocol, (2) an infrared (IR) laser for volume material ablation and particular soft desorption/ionization conditions, and (3) an orthogonal time-of-flight mass spectrometer for a high mass accuracy, independent of any irregularity of the silica gel surface. Chromatographic "mobility profiles" were determined by scanning the laser beam across the analyte bands. The current limit of detection for the MS analysis was determined to approximately 10 pmol of individual oligosaccharides spotted for chromatography. A liquid composite matrix, containing glycerol and the ultraviolet (UV-)MALDI matrix alpha-cyano-4-hydroxycinnamic acid, allows a direct HPTLC-MALDI-MS analysis with a 337 nm-UV laser as well. Compared to the IR-MALDI mode, the analytical sensitivity in UV-MALDI was found to be lower by one order of magnitude, whereas unspecific analyte ion fragmentation as well as adduct formation was found to be more extensive

Fraunfelder, F.T., Finnegan, M., Wilson, D.J., 2006. Conjunctival-corneal intraepithelial neoplasm in an Asian elephant (Elephas maximus). J. Zoo. Wildl. Med. 37, 424-426.
Abstract: An adult female Asian elephant (Elephas maximus) presented with an enlarging nasal limbal mass of the left eye. The mass was excised and the surgical bed treated with liquid nitrogen cryotherapy. Histopathologic examination of the excised tissue showed the mass to be a superficial dysplastic ocular lesion, or conjunctival intraepithelial neoplasm. A 5-yr follow-up period has passed without complications or recurrence, suggesting that as is the case in humans (Homo sapiens), excision and cryotherapy is an effective treatment for these lesions in elephants. This is the first report of any ocular neoplasia in an elephant

Goodwin, T.E., Eggert, M.S., House, S.J., Weddell, M.E., Schulte, B.A., Rasmussen, L.E., 2006. Insect pheromones and precursors in female African elephant urine
450. Journal of Chemical Ecology 32, 1849-1853.
Abstract: Using automated solid-phase dynamic extraction and gas chromatography-mass spectrometry, our search for urinary chemical signals from ovulatory female African elephants (Loxodonta africana) has revealed the bark beetle aggregation pheromones frontalin, exo-brevicomin, and endo-brevicomin, as well as their precursors and the aphid alarm pheromones (E,E)-alpha-farnesene and (E)-beta-farnesene. Enantiomeric ratios for brevicomins have been determined. Prior discovery of common insect/elephant pheromones in Asian elephants, namely, (Z)-7-dodecenyl acetate and frontalin, suggests that the present findings may yield valuable insights into chemical communication among African elephants

Lintner, R., Stoeger-Horwath, A.S., Schwammer, H.M., Kratochvil, H. Sound invention in African elephants (Loxodonta africana). Proceedings International Elephant Conservation & Research Symposium.  256-259. 2006. 2006.
Ref Type: Conference Proceeding

Nissani, M., 2006. Do Asian elephants (Elephas maximus) apply causal reasoning to tool-use tasks?
511. J. Exp. Psychol. Anim Behav. Process 32, 91-96.
Abstract: Two experiments addressed contradictory claims about causal reasoning in elephants. In Experiment 1, 4 Asian elephants (Elephas maximus) were pretrained to remove a lid from the top of a bucket and retrieve a food reward. Subsequently, in the first 5 critical trials, when the lid was placed alongside the bucket and no longer obstructed access to the reward, each elephant continued to remove the lid before retrieving the reward. Experiment 2, which involved 11 additional elephants and variations of the original design, yielded similarly counterintuitive observations. Although the results are open to alternative interpretations, they appear more consistent with associative learning than with causal reasoning. Future applications of Fabrean methodologies (J. H. Fabre, 1915) to animal cognition are proposed

Plotnik, J.M., de Waal, F.B., Reiss, D., 2006. Self-recognition in an Asian elephant
389. Proc. Natl. Acad. Sci. U. S. A 103, 17053-17057.
Abstract: Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. We exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus "mark test" for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation

Reznikova, Z., 2006. [The study of tool use as the way for general estimation of cognitive abilities in animals]
496. Zh. Obshch. Biol. 67, 3-22.
Abstract: Investigation of tool use is an effective way to determine cognitive abilities of animals. This approach raises hypotheses, which delineate limits of animal's competence in understanding of objects properties and interrelations and the influence of individual and social experience on their behaviour. On the basis of brief review of different models of manipulation with objects and tools manufacturing (detaching, subtracting and reshaping) by various animals (from elephants to ants) in natural conditions the experimental data concerning tool usage was considered. Tool behaviour of anumals could be observed rarely and its distribution among different taxons is rather odd. Recent studies have revealed that some species (for instance, bonobos and tamarins) which didn't manipulate tools in wild life appears to be an advanced tool users and even manufacturers in laboratory. Experimental studies of animals tool use include investigation of their ability to use objects physical properties, to categorize objects involved in tool activity by its functional properties, to take forces affecting objects into account, as well as their capacity of planning their actions. The crucial question is whether animals can abstract general principles of relations between objects regardless of the exact circumstances, or they develop specific associations between concerete things and situations. Effectiveness of laboratory methods is estimated in the review basing on comparative studies of tool behaviour, such as "support problem", "stick problem", "tube- and tube-trap problem", and "reserve tube problem". Levels of social learning, the role of imprinting, and species-specific predisposition to formation of specific domains are discussed. Experimental investigation of tool use allows estimation of the individuals' intelligence in populations. A hypothesis suggesting that strong predisposition to formation of specific associations can serve as a driving force and at the same time as obstacle to animals' activity is discussed. In several "technically gifted" species (such as woodpecker finches, New Caledonian crows, and chimpanzees) tool use seems to be guided by a rapid process of trial and error learning. Individuals that are predisposed to learn specific connections do this too quickly and thus become enslaved by stereotypic solutions of raising problems.

Steinmetz, R., Chutipong, W., Seuaturien, N., 2006. Collaborating to conserve large mammals in Southeast Asia
405. Conserv. Biol. 20, 1391-1401.
Abstract: Depressed mammal densities characterize the interior of many Southeast Asian protected areas, and are the result of commercial and subsistence hunting. Local people are part of this problem but can participate in solutions through improved partnerships that incorporate local knowledge into problem diagnosis. The process of involving local people helps build a constituency that is more aware of its role (positive and negative) in a protected area and generates site-specific conservation assessments for management planning. We illustrate the practical details of initiating such a partnership through our work in a Thai wildlife sanctuary. Many protected areas in Southeast Asia present similar opportunities. In local workshops, village woodsmen were led through ranking exercises to develop a spatially explicit picture of 20-year trends in the abundance of 31 mammal species and to compare species-specific causes for declines. Within five taxonomic groups, leaf monkeys (primates), porcupines (rodents), tigers (large carnivores), civets (small carnivores), and elephants (ungulates) had declined most severely (37-74%). Commercial hunting contributed heavily to extensive population declines for most species, and subsistence hunting was locally significant for some small carnivores, leaf monkeys, and deer. Workshops thus clarified which species were at highest risk of local extinction, where the most threatened populations were, and causes for these patterns. Most important, they advanced a shared problem definition, thereby unlocking opportunities for collaboration. As a result, local people and sanctuary managers have increased communication, initiated joint monitoring and patrolling, and established wildlife recovery zones. Using local knowledge has limitations, but the process of engaging local people promotes collaborative action that large mammals in Southeast Asia need

Stoeger-Horwath, A.S., Schwammer, H.M., Kratochvil, H., Stoeger, S. Infant talk - first insights into the vocal ontogeny of elephants (Loxodonta africana). Proceedings International Elephant Conservation & Research Symposium.  178-181. 2006. 2006.
Ref Type: Conference Proceeding

Weidner, E.B., Isaza, R., Galle, L.E., Barrie, K., Lindsay, W.A., 2006. Medical management of a corneal stromal abscess in a female Asisan elephant (Elephas maximus). Journal of Zoo and Wildlife Medicine 37, 397-400.

Wellehan, J.F.X., Johnson, A.J., Isaza, R. Identification of two novel herpesviruses associated with ocular inflammation in Asian elephants (Elephas maximus).
2006 Proceedings American Association of Zoo Veterinarians.  173. 2006.
Ref Type: Conference Proceeding
Abstract: Disease caused by a herpesvirus (EEHV) is a serious concern in Asian elephant (Elephas maximus) calves.  Herpesviruses are known for latency and life-long infections, with periodic shedding from mild inflammatory lesions in adapted adult hosts, and ocular disease has been seen with other herpesviruses in other species.  Ocular inflammation is not uncommonly seen in Asian elephants. Degenerate PCR primers targeting a conserved region of herpesvirus DNA-dependent DNA polymerase were used to amplify products from eye swabs of eight Asian elephants with epiphora, blepharitis, and conjunctivitis.  Nucleotide sequencing of the PCR products showed two novel herpesviruses distinct from EEHV.  Comparative sequence analysis shows that these viruses are probable members of the subfamily Gammaherpesvirinae. The sequence phylogeny of these viruses has implications for both viral and host evolution.  Further understanding and characterization of these viruses is needed to understand their role in elephant health.

Wiedner, E.B., Isaza, R., Galle, L.E., Barrie, K., Lindsay, W.A., 2006. Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus). J. Zoo. Wildl. Med. 37, 397-400.
Abstract: A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk

Wiedner, E.B., Isaza, R., Galle, L.E., Barrie, K., Lindsay, W.A., 2006. Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus). Journal of Zoo and Wildlife Medicine 37, 397-400.
Abstract: A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk.

Clemins, P.J., Johnson, M.T., Leong, K.M., Savage, A., 2005. Automatic classification and speaker identification of African elephant (Loxodonta africana) vocalizations. J Acoust Soc Am. 117, 956-963.
Abstract: A hidden Markov model (HMM) system is presented for automatically classifying African elephant vocalizations. The development of the system is motivated by
successful models from human speech analysis and recognition. Classification features include frequency-shifted Mel-frequency cepstral coefficients (MFCCs)
and log energy, spectrally motivated features which are commonly used in human speech processing. Experiments, including vocalization type classification and
speaker identification, are performed on vocalizations collected from captive elephants in a naturalistic environment. The system classified vocalizations with accuracies of 94.3% and 82.5% for type classification and speaker identification classification experiments, respectively. Classification accuracy, statistical significance tests on the model parameters, and qualitative analysis support the effectiveness and robustness of this approach for vocalization analysis in nonhuman species.
Speech and Signal Processing Laboratory, Marquette University, Milwaukee, Wisconsin 53233-1881, USA. patrick.clemins@marquette.edu

Clemins, P.J., Johnson, M.T., Leong, K.M., Savage, A., 2005. Automatic classification and speaker identification of African elephant (Loxodonta africana) vocalizations
633. J. Acoust. Soc. Am. 117, 956-963.
Abstract: A hidden Markov model (HMM) system is presented for automatically classifying African elephant vocalizations. The development of the system is motivated by successful models from human speech analysis and recognition. Classification features include frequency-shifted Mel-frequency cepstral coefficients (MFCCs) and log energy, spectrally motivated features which are commonly used in human speech processing. Experiments, including vocalization type classification and speaker identification, are performed on vocalizations collected from captive elephants in a naturalistic environment. The system classified vocalizations with accuracies of 94.3% and 82.5% for type classification and speaker identification classification experiments, respectively. Classification accuracy, statistical significance tests on the model parameters, and qualitative analysis support the effectiveness and robustness of this approach for vocalization analysis in nonhuman species

Garstang, M., 2005. Long-distance, low-frequency elephant communication. J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 191, 299.
Abstract: Erratum: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2004; Oct;190(10):791-805. Epub 2004 Sep 2. The production, transmission, and reception of and the behavioral response to long-distance, low-frequency sound by elephants is reviewed. The structure of low-frequency calls generated by elephants is separated into the "source" and the "filter" roles played by the lungs, larynx and vocal track, the composition of the expired air and the ambient air temperature. Implications regarding the size, age, sex, sexual and physical status follow from the call structure and detection. Reception of the signal is discussed in terms of the characteristics of the elephant's ear with particular attention to the determination of the threshold of hearing and the ability to locate the source of low-frequency sounds. Factors which influence the transmission of near infrasound are related to atmospheric structure. The critical role played by the thermal stratification and vertical gradient and magnitude of the wind in determining both the range and the detection of a signal are discussed for open and closed elephant habitats. Infrasound plays a pervasive role in reproduction, resource utilization, avoidance of predation and other social interactions. Current and future technology can be expected to contribute to the detection and interpretation of elephant communication. This will aid in the understanding of behavior and in efforts to sustain the species.

Greenwood, D.R., Comeskey, D., Hunt, M.B., Rasmussen, L.E., 2005. Chemical communication: chirality in elephant pheromones
528. Nature 438, 1097-1098.
Abstract: Musth in male elephants is an annual period of heightened sexual activity and aggression that is linked to physical, sexual and social maturation. It is mediated by the release of chemical signals such as the pheromone frontalin, which exists in two chiral forms (molecular mirror images, or enantiomers). Here we show that enantiomers of frontalin are released by Asian elephants in a specific ratio that depends on the animal's age and stage of musth, and that different responses are elicited in male and female conspecifics when the ratio alters. This precise control of communication by molecular chirality offers insight into societal interactions in elephants, and may be useful in implementing new conservation protocols

Leong, K.M., Burks, K., Rizkalla, C.E., Savage, A., 2005. Effects of reproductive and social context on vocal communication in captive female African elephants (Loxodonta africana). Zoo Biology 24, 331-347.
Abstract: Female African elephants advertise changes in reproductive condition to males through a variety of modalities, including an increase in low-frequency vocalizations, presumed to travel long distances.  Although males respond to these vocalizations, it has been suggested that their proximate function may be to signal to nearby females rather than to distant males. Because elephants live in a female-bonded society, it is likely  that  changes in female reproductive condition also affect close-range  interactions between high- and low-ranking females and that  vocalizations  may mediate these interactions. To examine female-female interactions related to vocal production and the ovulatory cycle, this year-long study monitored behavior, vocalizations and hormonal cycles for a group of six female captive African elephants at Disney's Animal Kingdom. Rates of several types of close-range interactions were observed to change over the phases of the estrous cycle, and rank seemed to affect whether or not low-frequency vocalizations were given in association with these interactions. Results of this study suggest that a female African  elephant's  immediate social context and rank in the social hierarchy interact with  the  hormonal cycle in the production of low-frequency vocalizations, thus  many  of these vocalizations may not function proximately as signals to  distant  males, but may be a result of the changing dynamics among females.

Nissani, M., Hoefler-Nissani, D., Lay, U.T., Htun, U.W., 2005. Simultaneous visual discrimination in Asian elephants
631. J. Exp. Anal. Behav. 83, 15-29.
Abstract: Two experiments explored the behavior of 20 Asian elephants (Elephas aximus) in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3 sessions and 293 trials. One elephant failed to reach criterion in the white+/black- task in 9 sessions and 549 trials, and 2 elephants failed to reach criterion in the black+/white- task in 9 sessions and 452 trials. In Experiment 2, 3 elephants learned a large/small transposition problem, reaching criterion within a mean of 1.7 sessions and 58 trials. Four elephants failed to reach criterion in 4.8 sessions and 193 trials. Data from both the black/white and large/small discriminations showed a surprising age effect, suggesting that elephants beyond the age of 20 to 30 years either may be unable to acquire these visual discriminations or may require an inordinate number of trials to do so. Overall, our results cannot be readily reconciled with the widespread view that elephants possess exceptional intelligence

Poole, J.H., Tyack, P.L., Stoeger-Horwath, A.S., Watwood, S., 2005. Animal behaviour: elephants are capable of vocal learning
623. Nature 434, 455-456.
Abstract: There are a few mammalian species that can modify their vocalizations in response to auditory experience--for example, some marine mammals use vocal imitation for reproductive advertisement, as birds sometimes do. Here we describe two examples of vocal imitation by African savannah elephants, Loxodonta africana, a terrestrial mammal that lives in a complex fission-fusion society. Our findings favour a role for vocal imitation that has already been proposed for primates, birds, bats and marine mammals: it is a useful form of acoustic communication that helps to maintain individual-specific bonds within changing social groupings

Roca, A.L., O'Brien, S.J., 2005. Genomic inferences from Afrotheria and the evolution of elephants
558. Curr. Opin. Genet. Dev. 15, 652-659.
Abstract: Recent genetic studies have established that African forest and savanna elephants are distinct species with dissociated cytonuclear genomic patterns, and have identified Asian elephants from Borneo and Sumatra as conservation priorities. Representative of Afrotheria, a superordinal clade encompassing six eutherian orders, the African savanna elephant was among the first mammals chosen for whole-genome sequencing to provide a comparative understanding of the human genome. Elephants have large and complex brains and display advanced levels of social structure, communication, learning and intelligence. The elephant genome sequence might prove useful for comparative genomic studies of these advanced traits, which have appeared independently in only three mammalian orders: primates, cetaceans and proboscideans

Roth, G., Dicke, U., 2005. Evolution of the brain and intelligence
612. Trends Cogn Sci. 9, 250-257.
Abstract: Intelligence has evolved many times independently among vertebrates. Primates, elephants and cetaceans are assumed to be more intelligent than 'lower' mammals, the great apes and humans more than monkeys, and humans more than the great apes. Brain properties assumed to be relevant for intelligence are the (absolute or relative) size of the brain, cortex, prefrontal cortex and degree of encephalization. However, factors that correlate better with intelligence are the number of cortical neurons and conduction velocity, as the basis for information-processing capacity. Humans have more cortical neurons than other mammals, although only marginally more than whales and elephants. The outstanding intelligence of humans appears to result from a combination and enhancement of properties found in non-human primates, such as theory of mind, imitation and language, rather than from 'unique' properties

Shoshani, J., Tassy, P., 2005. Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior. Quaternary International 126-128, 5-20.
Abstract: With the addition of 13 new taxa, we recognized 175 species and subspecies of proboscideans, classified in 42 genera and 10 families. The three extant species are: forest African elephant (Loxodonta cyclotis), bush African elephant (L. africana), and Asian elephant (Elephas maximus, with three subspecies). Rigorous analysis of characters published or awaiting publication is imperative for better understanding of the cladistic relationships among currently recognized proboscideans. Here we focus on ''aquatic ancestry'' of Proboscidea, interordinal relationships within Placentalia, proboscidean taxonomy in general and South American in particular, anatomy and physiology and some ecological considerations. New taxa above the family level include sister taxa Mammutida and Elephantida, and Plesielephantiformes as a sister taxon to Elephantiformes. Neontological research is currently under way on the hyoid apparatus, lungs, brain, hearing, ecology and behavior. Topics for future research include: phylogenetic positions of anthracobunids, Moeritherium, tetralophodont gomphotheres, Stegolophodon and Stegodon, and intra-familial relationships among Loxodonta, Elephas and Mammuthus, and continuing studies on encephalization quotient. Certain anatomical features and functions (e.g., the hyoid apparatus that helps in food procurement, in production of infrasonic sounds, and in storing water to be used in time of stress) evolved about 25 million years ago, in time for diversification into new niches when grasses appeared in the landscape.

Soltis, J., Leong, K., Savage, A., 2005. African elephant vocal communication II: Rumble variation reflects the individual identity and emotional state of callers. Animal Behaviour 70, 589-599.
Abstract: The most common vocalization of the African elephant, Loxodonta  africana, is the rumble, but there is no consensus as to how many rumble subtypes exist. From the standpoint of social function, many types of rumble have been proposed. From a structural standpoint, however, few studies have examined detailed acoustic measurements of a large number of calls. We analysed 270 rumbles from six adult female African elephants housed at Disney's Animal Kingdom (Lake Buena Vista, Florida, U.S.A.). Subjects wore collars outfitted with microphones and radiotransmitters that allowed recording of vocalizations from identified individuals. Rumble vocalizations were digitized and both source and filter features were measured for each call. Behavioural and endocrine data were collected so that acoustical data could be placed into the context of ongoing social behaviour and reproductive state. Multidimensional scaling analysis revealed that, from a structural standpoint, rumbles from this captive setting could not be divided into distinct subtypes, but there was extensive acoustic variation across rumbles. Discriminant function analysis and MANOVA were employed to further explore this variation. First, acoustic characteristics varied according to the individual identity of the caller. Second, rumbles varied as a function of negative emotional arousal. When associating with dominant animals, subordinate females produced rumbles with lower cepstral coefficients, suggesting low tonality and unstable pitch in the voice, compared to rumbles produced outside of the presence of dominant animals. Rumbles as a whole did not cluster into distinct acoustic types, but structural variation in rumbles reflected the individual identity and emotional state of callers.

Soltis, J., Leong, K., Savage, A., 2005. African elephant vocal communication I: Antiphonal calling behaviour among affiliated females. Animal Behaviour 70, 579-587.
Abstract: African elephants, Loxodonta africana, are well known for their use of a low-frequency 'rumble' vocalization, which is thought to function in long-distance communication. Less work, however, has been conducted on short-distance communication within groups, and on spontaneously occurring vocal exchanges among identified individuals in particular. This is due in part to the fact that low-frequency rumbles are difficult to assign to individual callers. We collected vocal data on a group of six female African elephants housed at Disney's Animal Kingdom to determine whether they exchange rumbles in alternating sequences (also known as antiphonal calling). Subjects wore collars outfitted with microphones and radiotransmitters that allowed identification of individual callers, and behavioural and endocrine data were collected so that vocal activity could be examined in the context of social behaviour and reproductive state. First, we found that females did not produce rumbles at random, but were nearly twice as likely to produce rumbles shortly after rumbles from other group members. Second, the relative dominance rank and reproductive state of callers did not affect the probability of vocal response, but affiliative relationship with the caller had a strong influence on rumble response.  Females were most likely to respond in kind to the rumbles of their most affiliated partners compared to less affiliated group members. Third, video analysis showed that rumble exchanges occurred in variable contexts, including when animals were out of contact, during reunions, and while in close proximity. Also, affiliated partners often vocalized in sequence when approached by dominant individuals. The results of these analyses show that affiliated female African elephants exchange rumbles antiphonally, and imply multiple functions for such vocal exchanges.

Suedmeyer, W.K., Oosterhuis, J., Kollias, G., Fagan, D., Hornoff, B., Dodam, J., Shafford, H. Elephant restraint device assisted anesthesia in an African elephant (Loxodonta africana). 2005 Proceedings AAZV, AAWV, AZA Nutrition Advisory Group.  189-191. 2005.
Ref Type: Conference Proceeding
Abstract: Modern elephant management programs often include the use of protected contact. This allows improved safety for the elephant staff but may limit access to medical conditions occurring in elephants.
A 27-yr-old female African elephant (Loxodonta africana) weighing an estimated 3,700 kg was anesthetized for evaluation of a chronic, progressive, fistulous tract of the left ventral mandible. The mandible was routinely cultured, flushed with diluted peroxide, chlorhexidine, betadine solution, or alternating antibiotics, based on microbial sensitivities. To properly assess the left mandible, the elephant had to be placed in right lateral recumbency, which was accomplished with the use of a commercially available rotational elephant restraint device (ERD). Because of the protected contact management program, right lateral recumbency could not be guaranteed at the time of immobilization. Malpositioning, tusk fracture and/or related injury could occur upon recumbency without the additional control afforded by the ERD. The ERD is a hydraulically operated unit that comfortably restrains an elephant, minimizing safety risks to the animal and staff. The ERD consists of one solid wall, three side panels, and hinged floor. The ends of the restraint are closed with moveable shift doors. The three side panels can be moved independently depending upon the size of the animal and are further subdivided with moveable "subpanels" to allow direct access to various areas of the animal. In addition, support straps help gently stabilize limbs when performing medical procedures. The unit is positioned within the elephant holding facility at the Kansas City Zoo. The unit was installed in 1994 during renovation of the elephant exhibit, whereupon the elephant management program was changed from free-contact to protected contact. The ERD is utilized for reproductive assessments, semen collection, transabdominal ultrasound, evaluation of integumentary wounds, ophthalmic and aural examination, and administration of injectable medications. However, no elephant had been anesthetized and rotated in the restraint. The affected animal could not be guaranteed to re-enter the ERD once rotated, but would enter and station in the ERD on a daily basis. Because of this, a conspecific was conditioned to allow rotation without the use of sedatives or tranquilizers, to prepare for the actual immobilization. Adjustments in strap placement, cushioning, critical evaluation of mechanical stability, and placement of hydraulic panels allowed staff to prepare for the actual immobilization, minimizing complications. The elephant was conditioned to enter and station in the ERD. After strapping the distal limbs, thorax and caudal abdomen for support, the elephant was immobilized with a combination of 3,000 IU of hyaluronidase (O'Brien Pharmacy, Kansas City, MO USA), 10 mg acepromazine maleate, and 7 mg etorphine hydrochloride (Wildlife Pharmaceuticals Inc., Fort Collins, CO USA) via pole syringe. Close monitoring of induction was performed and when stage III anesthetic plane was achieved, the elephant was rotated into right lateral recumbency, elevating the elephant 6 feet above the floor. No voluntary movement of the animal was noted while the restraint was in motion. Direct arterial blood pressure, indirect oscillometric blood pressure, blood gases, respiratory rate, excursion characteristics, cardiac rate and rhythm, and pulse oximetry was routinely monitored during the procedure. Anesthesia was maintained with intermittent boluses of etorphine hydrochloride. Intravenous physiologic fluids (lactated Ringers solution) were maintained via an i.v. aural catheter, and insufflation with oxygen was provided on a continual basis. Oral examination and palpation demonstrated an incomplete transverse fissure of the left mandibular molar, intact gingival, and proper dental occlusion with the upper arcade.  Digital radiographs of the left mandible were performed based on exposures obtained with a set of skeletonized jaws. Advantages of this diagnostic modality are the immediate imaging results, portability, and digital imaging and storage, and does not require a developer or fixative. Adjustments in radiographic angle and technique were made to obtain the best diagnostic image. Radiographic imaging demonstrated a sequestrum consisting of a fractured enamel plate  2of the mandibular molar with a fistulous tract that coursed ventrally to communicate through the skin. The elephant was elevated 6 feet above the ground, which presented unique challenges. Because of the relatively small operating space, intubation was not possible, but insufflation was readily achieved and successful based on pulse oximetry trends. A commercial lift was utilized to elevate two large-animal circle anesthetic units to the level of the elephant's head. During immobilization the legs were cushioned and restraint straps removed to lessen the potential for occlusive damage to the tissues. The ERD allows an elephant to be positioned in either right or left lateral recumbency.
Upon completion of diagnostic procedures, the narcotic agent was reversed with 1,400 mg naltrexone hydrochloride (Zoopharm, Laramie, WY USA) administered 25% intravenously and 75% subcutaneously. The elephant awoke within 90 sec and was rotated to a standing position within the restraint. Thereafter, the elephant was confined in the restraint for approximately 45 min, until no untoward effects were likely to occur. The elephant was released from the restraint and resumed normal eating and drinking within 8 hr, and voluntarily entered the restraint within 2 wk following the procedure. The elephant was stable throughout the procedure; however, a predetermined objective for mean arterial blood pressures (<200 MAP) was not achieved. Hyaluronidase was utilized to promote rapid absorption of the narcotic and neuroleptic agents.3 Acetylpromazine was used to maintain peripheral perfusion by reducing the hypertensive effects of etorphine,1 which has been documented in previous immobilizations of African elephants.3-5 Etorphine hydrochloride, a powerful narcotic agent, has been successfully used as an immobilizing agent in both wild and captive African elephants.3-5 Use of an ERD allowed full control of the immobilization, increasing safety for personnel, preventing injury to the elephant, and positioning the left mandible on the dorsal plane. Disadvantages are the elevated height of the elephant, relatively small operating space, and disrupted line of sight communication. A second procedure will be performed in the near future to address the fracture and subsequent sequestrum diagnosed during the first immobilization. The elephant is currently being conditioned to allow restraint in a holding stall that will allow greater access to the oral cavity and surgical manipulation of the affected mandible.
ACKNOWLEDGMENTS
We thank the staff of the Kansas City Zoological Park for their care, concern, and expertise in helping make this procedure a success.
LITERATURE CITED
1 Booth, N.H. Psychotropic agents. In: Booth, N.H., and R.E. McDonald (eds.). Veterinary Pharmacology and Therapeutics.  W.B. Saunders, Co., Philadelphia, PA. P. 329.
2 Fagan, V.D.A., J.E. Oosterhuis, and A. Roocraft. 2001. Captivity disorders in elephants: impacted molars and broken tusks. Der Zoologische Garten 71:281-303.
3 Honeymoon, V.L., G.R. Pettifer, and D.H. Dyson. 1992. Arterial blood pressure and blood gas values in normal standing and laterally recumbent African (Loxodonta africana) and Asian (Elephas maximus)    elephants. J. Zoo Wildl. Med. 23:205-210.
4. Kock, R.A., P. Morkel, and M.D. Kock. 1993. Current immobilization procedures used in elephants. In: Fowler,
M.E. (ed.).  Zoo and Wild Animal Medicine: Current Therapy 3. W.B. Saunders Co., Philadelphia, PA.  Pp. 436-441.
5 Raath, J.P. 1999. Relocation of African elephants. In: Fowler, M.E., and R.E. Miller (eds.). Zoo and Wild Animal Medicine: Current Therapy 4. W.B. Saunders, Co., Philadelphia, PA.  Pp. 525-533.

Vidya, T.N.C., Sukumar, K., 2005. Social organization of the Asian elephant (Elephas maximus) in southern India inferred from microsatellite DNA. J Ethol 23, 205-210.
Abstract: Social organization of the Asian elephant (Elephas maximus) is not well understood in the absence of long-term studies of identified individuals. Adult Asian elephant females and their young offspring of both sexes form matriarchal groups, with pubertal males dispersing from natal groups, but whether these social groups represent families and whether males show locational or social dispersal were unknown. Using nuclear microsatellite loci amplified from dung-extracted DNA of free-ranging elephants in a large southern Indian population, we demonstrate that female-led herds comprise closely related individuals that are indeed families, and that males exhibit non-random locational dispersal.

Yokoyama, S., Takenaka, N., Agnew, D.W., Shoshani, J., 2005. Elephants and human color-blind deuteranopes have identical sets of visual pigments
626. Genetics 170, 335-344.
Abstract: Being the largest land mammals, elephants have very few natural enemies and are active during both day and night. Compared with those of diurnal and nocturnal animals, the eyes of elephants and other arrhythmic species, such as many ungulates and large carnivores, must function in both the bright light of day and dim light of night. Despite their fundamental importance, the roles of photosensitive molecules, visual pigments, in arrhythmic vision are not well understood. Here we report that elephants (Loxodonta africana and Elephas maximus) use RH1, SWS1, and LWS pigments, which are maximally sensitive to 496, 419, and 552 nm, respectively. These light sensitivities are virtually identical to those of certain "color-blind" people who lack MWS pigments, which are maximally sensitive to 530 nm. During the day, therefore, elephants seem to have the dichromatic color vision of deuteranopes. During the night, however, they are likely to use RH1 and SWS1 pigments and detect light at 420-490 nm

Yokoyama, S., Takenaka, N., Agnew, D.W., Shoshani, J., 2005. Elephants and human color-blind deuteranopes have identical sets of visual pigments. Genetics 170, 335-344.
Abstract: Being the largest land mammals, elephants have very few natural enemies and are acti ve during both day and night. Compared with those of diurnal and nocturnal animals, the eyes of elephants and other arrhythmic species, such as many ungulates and large carnivores, must function in both the bright light of day and dim light of night. Despite their fundamental importance, the roles of photosensitive molecules, visual pigments, in arrhythmic vision are not well understood. Here we report that elephants (Loxodonta africana and Elephas maximus) use RH1, SWS1, and LWS pigments, which are maximally sensitive to 496, 419, and 552 nm, respectively. These light sensitivities are virtually identical to those of certain "color-blind" people who lack MWS pigments, which are maximally sensitive to 530 nm. During the day, therefore, elephants seem to have the dichromatic color vision of deuteranopes. During the night, however, they are likely to use RH1 and SWS1 pigments and detect light at 420-490 nm.

Garstang, M., 2004. Long-distance, low-frequency elephant communication. J Comp Physiol A 190, 791-805.
Abstract: The production, transmission, and reception of and the behavioral response to long-distance, low-frequency sound by elephants is reviewed. The structure of low-frequency calls generated by elephants is separated into the ''source'' and the ''filter'' roles played by the lungs, larynx and vocal track, the composition of the expired air and the ambient air temperature. Implications regarding the size, age, sex, sexual and physical status follow from the call structure and detection. Reception of the signal is discussed in terms of the characteristics of the elephant's ear with particular attention to the determination of the threshold of hearing and the ability to locate the source of low-frequency sounds. Factors which influence the transmission of near infrasound are related to atmospheric structure. The critical role played by the thermal stratification and vertical gradient and magnitude of the wind in determining both the range and the detection of a signal are discussed for open and closed elephant habitats. Infrasound plays a pervasive role in reproduction, resource utilization, avoidance of predation and other social interactions. Current and future technology can be expected to contribute to the detection and interpretation of elephant communication. This will aid in the understanding of behavior and in efforts to sustain the species.

Garstang, M., 2004. Long-distance, low-frequency elephant communication
686. J. Comp Physiol A Neuroethol. Sens. Neural Behav. Physiol 190, 791-805.
Abstract: The production, transmission, and reception of and the behavioral response to long-distance, low-frequency sound by elephants is reviewed. The structure of low-frequency calls generated by elephants is separated into the "source" and the "filter" roles played by the lungs, larynx and vocal track, the composition of the expired air and the ambient air temperature. Implications regarding the size, age, sex, sexual and physical status follow from the call structure and detection. Reception of the signal is discussed in terms of the characteristics of the elephant's ear with particular attention to the determination of the threshold of hearing and the ability to locate the source of low-frequency sounds. Factors which influence the transmission of near infrasound are related to atmospheric structure. The critical role played by the thermal stratification and vertical gradient and magnitude of the wind in determining both the range and the detection of a signal are discussed for open and closed elephant habitats. Infrasound plays a pervasive role in reproduction, resource utilization, avoidance of predation and other social interactions. Current and future technology can be expected to contribute to the detection and interpretation of elephant communication. This will aid in the understanding of behavior and in efforts to sustain the species

Gobbel, L., Fischer, M.S., Smith, T.D., Wible, J.R., Bhatnagar, K.P., 2004. The vomeronasal organ and associated structures of the fetal African elephant, Loxodonta africana (Proboscidea, Elephantidae). Acta Zoologica 85, 41-52.
Abstract: The vomeronasal organ (VNO) is a chemosensory structure of the nasal septum found in most tetrapods. Although potential behavioural correlates of VNO function have been shown in two of the three elephant species, its morphology in Loxodonta africana has not been studied. The development of the VNO and its associated structures in the African elephant are described in detail using serially sectioned material from fetal stages. The results show that many components of the VNO complex (e.g. neuroepithelium, receptor-free epithelium, vomeronasal nerve, paravomeronasal ganglia, blood vessels, vomeronasal cartilage) are well developed even in a 154-day-old fetus, in which the VNO opens directly into the oral cavity with only a minute duct present. However, the vomeronasal glands and their ducts associated with the VNO were developed only in the 210-day-old fetus. Notably, in this fetus, the vomeronasal-nasopalatine duct system had acquired a pathway similar to that described in the adult Asian elephant; the VNOs open into the oral cavity via the large palatal parts of the nasopalatine ducts, which are lined by a stratified squamous epithelium. The paired palatal ducts initially coursed anteriorly at an angle of  45degrees from the oral recess and/or the oral cavity mucosa, and merged into the vomeronasal duct. This study confirms the unique characteristics of the elephant VNO, such as its large size, the folded epithelium of the VNO tube, and the dorsomedial position of the neuroepithelium. The palatal position and exclusive communication of the VNO with the oral cavity, as well as the partial reduction of the nasopalatine duct, might be re

Gunther, R.H., O'Connell-Rodwell, C.E., Klemperer, S.L., ., 2004. Seismic waves from elephant vocalizations: A possible communication mode? Geophysical Research Letters 31 L11602.
Abstract: We conducted experiments with trained African elephants that show that low-frequency elephant vocalizations produce Rayleigh waves. We model a potential range for these seismic waves, under ideal conditions, of c. 2 km. In appropriate conditions, surface waves from an elephant's infrasonic vocalizations might propagate further than airborne sound and provide advantages over acoustic communication. However, if we use the
detection capabilities of the human ear as a benchmark for the signal-detection thresholds of elephants, our estimates of attenuation and ambient seismic noise suggest that the seismic detection range is unlikely to exceed the acoustic detection range under normal atmospheric conditions. We conclude that elephants may benefit from seismic detection in circumstances where the range of acoustic communication is limited, or in cases where multimodal communication is advantageous. Given our current uderstanding, elephants are unlikely to rely on seismic waves as their primary mode for long-range communication.

Hatfield, J.R., Samuelson, D.A., Lewis, P.A., Chisholm, M., 2004. Structure and presumptive function of the iridocorneal angle of the West Indian manatee (Trichechus manatus), short-finned pilot whale (Globicephala macrorhynchus), hippopotamus (Hippopotamus amphibius), and African elephant (Loxodonta africana). Vet Ophthalmol. 6, 35-43.
Abstract: The iridocorneal angles of prepared eyes from the West Indian manatee, short-finned pilot whale, hippopotamus and African elephant were examined and compared using light microscopy. The manatee and pilot whale demonstrated capacity for a large amount of aqueous outflow, probably as part of a system compensating for lack of ciliary musculature, and possibly also related to environmental changes associated with life at varying depths. The elephant angle displayed many characteristics of large herbivores, but was found to have relatively low capacity for aqueous outflow via both primary and secondary routes. The hippopotamus shared characteristics with both land- and water-dwelling mammals; uveoscleral aqueous outflow may be substantial as in the marine mammals, but the angular aqueous plexus was less extensive and a robust pectinate ligament was present. The angles varied greatly in size and composition among the four species, and most structures were found to be uniquely suited to the habitat of each animal. Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA.

Lazar, J., Rasmussen, L.E., Greenwood, D.R., Bang, I.S., Prestwich, G.D., 2004. Elephant albumin: a multipurpose pheromone shuttle
691. Chem. Biol. 11, 1093-1100.
Abstract: (Z)-7-dodecenyl acetate (Z7-12:Ac) is present in the urine of female Asian elephants (Elephas maximus) approaching ovulation and functions as a female-to-male sex pheromone. Here we show that a significant fraction of the pheromone in the urine is bound to a protein, elephant serum albumin (ESA), and provide evidence for key physiological functions of urinary ESA. Our biochemical and behavioral experiments suggest a three-fold role of ESA in pheromone signaling: (1) transporting Z7-12:Ac from serum into urine; (2) extending the presence of the pheromone in the environment without hampering detection; and (3) targeting pheromone delivery to chemosensory organs through localized release of the ligand induced by a pH change. The exploitation of albumin in pheromone transport clearly distinguishes the elephant from other mammals studied, and complements the uniqueness of elephant anatomy, physiology, and behavior

Leal, W.S., 2004. Pheromone unwrapping by pH flip-flopping
692. Chem. Biol. 11, 1029-1031.
Abstract: The Asian elephant utilizes the same sex pheromone as a number of moth species, (Z)-7-dodecen-1-yl acetate encapsulated in a serum-derived albumin. The chemical signal is emitted in the urine and received in the mucus of the trunk. The unwrapping of the package is pH mediated

Osofsky, S.A., Karesh, W., Kock, M.D., Kock, R., Cook, R.A. Moving conservation ahead (animal health for the environment and development): Progress at the intersection of program and policy. 2004 PROCEEDINGS AAZV, AAWV, WDA JOINT CONFERENCE.  406-407. 2004.
Ref Type: Conference Proceeding
Abstract: Our organizations hosted a highly interactive forum at which invited Southern and East African and other experts shared their vision for conservation and development success at the wildlife / livestock interface with IUCN World Parks Congress attendees and invited representatives from bilateral and multilateral development agencies and other interested parties. African governmental and nongovernmental experts from Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe participated.1 Our goal was to foster a sharing of ideas among African practitioners and development professionals that will lead to concrete and creative initiatives that address conservation and development challenges related to health at the livestock/wildlife/human interface. The focus was, appropriately, on ongoing efforts and future needs in and around the region's flagship protected areas and conservancies and their buffer zones- the places where tensions and challenges at the livestock/wildlife interface are often greatest. Discussions and planning focused on several themes of critical importance to the future of animal agriculture, wildlife, and, of course, people: competition over grazing and water resources, disease mitigation, local and global food security, zoonoses, and other potential sources of conflict related to the overall challenges of land-use planning and the pervasive reality of resource constraints. We have since been working to develop the most promising collaborative concepts that emerged from this forum into a suite of projects, grounded in real landscapes but cognizant of the critical need for policy reform, and based on the solid professional partnerships we believe are emanating from the AHEAD (Animal Health for the Environment And Development) enabling environment.
As we look around the world, impacts from interactions between livestock and wildlife (and habitat) are often profound. The issues at this interface represent an unfortunately all-too-often neglected sector of critical importance to the long-term ecological and sociopolitical security of protected areas and grazing lands worldwide. With its initial focus on Southern and East Africa and its diverse land-use mosaic, we believe the AHEAD initiative can help facilitate collaborative work with and among African partners to continue to bring sound science to bear on natural resource management decisions that directly affect the livelihoods and cultures of Africa's people, including those decisions that impact the future of Africa's protected areas and wildlife resources. As socioeconomic progress demands sustained improvements in health for humans, their domestic animals, and the environment, we recognize the need to utilize a "one health" perspective-an approach that was the foundation of our discussions at the World Parks Congress, and that has guided the follow-on work since. Since the September 2003 program launch, AHEAD has helped catalyze the development of several innovative regional projects that focus on the health / conservation nexus. In addition, the importance of these issues was formally recognized by the IUCN World Parks Congress when it officially included "Disease and Protected Area Management" as a key emerging issue in its "Emerging Issues" documentation: (http://www.iucn.org/themes/wcpa/wpc2003/english/outputs/durban/eissues.htm), which is the first time ecosystem health issues have been addressed like this in the Congress' 40-yr history.The text from the "Disease and Protected Area Management" section is below.
Disease and Protected Area Management
The health of wildlife, domestic animals and people are inextricably linked. Small improvements in the health of domestic and wild animals and thus their productivity can lead to dramatic improvements in human livelihoods and thus the reduction of poverty. Alien invasive pathogens should be addressed with vigor equal to that devoted to addressing more 'visible' alien invasive species. The role of disease in protected areas and the land-use matrix within which they are embedded must be recognized and addressed within the context of protected area and landscape-level planning and management.
Animal and human health-based indicators may reveal perturbations to natural systems not detectable by more commonly employed methodologies, thus improving the quantitative evaluation of trends in a protected area's health and resilience.

1The WCSAHEAD website is at www.wcs-ahead.org and includes the complete agenda from the World Parks Congress (Durban) AHEAD launch, abstracts of presentations, the presentation slidesets themselves, biographical sketches and contact details for most of the invitees, as well as a range of downloadable video and audio clips from
the forum.

Barasa, A., 2003. Morphology and structure of the nictitating membrane cartilage in mammals. Morphologie 87, 5-12.
Abstract: In 30 species of Mammals of varying body size (from rat to elephant), the form, dimensions and structure of the cartilage of the third eyelid were studied. The cartilage is a thin lamina concave in its corneal side, usually elongated in the oro-aboral direction. In the most species studied the outline of the cartilage may be inscribed in a triangle with a oral base, a dorsal margin, a ventral margin and an aboral apex. A study of stained sections revealed, in more than half of species, the presence of elastic fibres in the aboral part of cartilage; these fibres are particularly numerous, but non uniformly distributed, in the Equidae, lion and Suidae. Departement de Morphophysiologie Veterinaire, Rue L. de Vinci 44, 10095 Grugliasco, Italie.

Clausen, B., 2003. Elephant clinic. A mobile elephant clinic in Thailand. Experiences in the first two years. Dansk Veterinaertidsskrift 86, 20-25.
Abstract: From the most recent figures available (1998), it appears that there are probably more tame elephants (2257) than wild elephants(1300-3000) in Thailand. In August 1999 a mobile elephant clinic was set up using local and Danish personnel; the clinic was financed by the RSPCA and is based in Lampang, northern Thailand, and provides free medical care, medication and advice for the tame elephants in the country. The age of the treated animals ranged from below 1 year to over 56 years, with most being 36-40. The treatments given to 164 elephants during the 2-year period are tabulated; 53% were male, 60% were involved in the tourist industry and 37% in forestry. Most treatments (151, 32.5%) were for routine care of hooves and skin, poor condition (107, 23.1%), chronic wounds (42, 9.1%), digestive problems (26, 5.6%), and acute eye problems (25, 5.4%). Details of the treatments and the drugs used are given. The place of tame elephants in the economy of the country is discussed.

Cristoffer, C., Peres, C.A., 2003. Elephants versus butterflies: the ecological role of large herbivores in the evolutionary history of two tropical worlds. Journal of Biogeography 9, 1357-1380.
Abstract: Aim Large herbivores have important effects upon Paleotropical ecosystems, but attain much lower biomass densities in the Neotropics. We assess how this difference in herbivore activity has generated different ecological and evolutionary trajectories in the New and Old World tropics. We also propose an explanation for how the greater biomass density in the Old World came about. Location Data were compiled primarily from moist tropical forests, although more of the relevant information to address most of our hypotheses was available from the mainland areas of Africa, Asia, and South America than elsewhere. Methods We gleaned data from published information and personal communication. We compared body masses and a variety of other types of information for the New- and Old-World tropics. We proposed that interhemispheric differences exist in a variety of processes, including herbivory, frugivory, and flower visitation. We erected hypotheses and evaluated them qualitatively, and, when information was available, tested them using simple ratios of species in various taxonomic and trophic categories. To make the comparisons more meaningful, we specified appropriate data selection criteria. Results A general pattern of differences emerges from this review.  Compared with Neotropical forests, the much greater biomass densities of large herbivores in Paleotropical forests are associated with a lesser diversity of small herbivores, different hunting methods used by indigenous humans, larger arboreal vertebrates, larger fruits, different patterns of fruit and flower dispersion in space and time, a lesser abundance of most types of reproductive plant parts, and other features. The existence of a species-rich fauna of large herbivores in the pre-Holocene Neotropical rain forest was not supported. Main conclusions: The potential for large herbivores to cause functional differences between the New and Old World tropical forests has been virtually unexplored, despite the well-known importance of large herbivores in the Old World tropics. The evaluations of our hypotheses suggest that the abundance of large herbivores in the Old World tropics has launched it onto a different evolutionary trajectory than that of the NewWorld tropics. The relevant evidence, although scanty, suggests that the interhemispheric ecological differences are not an artefact of recent megafaunal extinctions in the New World. Recent human activities have, however, reduced population sizes of large wild herbivores in the Old World, and increased population sizes of livestock. This has likely created a rather homogeneous, anthropogenic selection pressure that tends to erase the evolutionary differences between the two tropical worlds.

Leong, K.M., Ortolani, A., Graham, L.H., Savage, A., 2003. The use of low-frequency vocalizations in African elephant (Loxodonta africana) reproductive strategies. Horm Behav. 43, 433-443.
Abstract: Fertility-advertisement calls in females are predicted to occur in nonmonogamous species where males and females are widely separated in space. In African elephants, low-frequency vocalizations have thus been suggested as a reproductive strategy used by fertile females to attract mates. This study examined the use of low-frequency vocalizations with respect to different phases of the estrous cycle in African elephants by simultaneously monitoring vocalizations, behavior, and hormonal profiles. Subjects were one male and six female African elephants housed at Disney's Animal Kingdom. No acoustically distinct vocalizations were restricted to the ovulatory follicular phase. However, overall rate of low-frequency vocalization as well as the rate of one acoustically distinct vocalization changed over the estrous cycle, with highest rates of calling related to the first period of follicular growth, or anovulatory follicular phase. Elevated rates of vocalization thus were not restricted to behavioral estrus and occurred much earlier in the estrous cycle than in most species that produce fertility-advertisement calls. Both herd composition and elephant identity also affected rates of vocalization. Vocalizations therefore may not be reliable signals of actual fertility. However, the increase in vocalizations in advance of estrus may attract males to the herd prior to ovulation, facilitating both male-male competition and female choice. Once present in the herd, males may then switch strategies to use more reliable chemical and visual cues to detect ovulating females. Disney's Animal Kingdom, Lake Buena Vista, FL 32830, USA. Kristen.Leong@disney.com

McComb, K., Reby, D., Baker, L., Moss, C., Sayialel, S., 2003. Long-distance communication of acoustic cues to social identity in African elephants. Animal Behaviour 65, 317-329.
Abstract: Research on long-distance vocal communication in mammals has tended to focus on the maximum distances over which a vocal signal might be physically detectable. For example, because elephants and some whales communicate using infrasonic calls, and low frequencies are particularly resilient to attenuation, it has often been assumed that these species can communicate over very long distances. However, a wide range of acoustic characteristics typically carry information on individual identity in mammalian calls, and frequency components crucial for social recognition could be distorted or lost as distance from the source increases. We used long-distance playback experiments to show that female African elephants, Loxodonta africana, can recognize a contact call as belonging to a family or bond group member over distances of 2.5 km, but that recognition is more usually achieved over distances of 1-1.5 km. We analysed female contact calls to distinguish source- and filter-related vocal characteristics that have the potential to code individual identity, and rerecorded contact calls 0.5-3.0 km from the loudspeaker to determine how different frequencies persist with distance. Our analyses suggest that the most important frequency components for long-distance communication of social identity may be well above the infrasonic range. When frequency components around 115 Hz become immersed in background noise, once propagation distances exceed 1 km, abilities for long-distance social recognition become limited. Our results indicate that the possession of an unusually long vocal filter, which appears to incorporate the trunk, may be a more important attribute for long-distance signalling in female African elephants than the ability to produce infrasound.

Payne, K.B., Thompson, M., Kramer, L., 2003. Elephant calling patterns as indicators of group size and composition: The basis for an acoustic monitoring system. African Journal of EcologyYear 41.
Abstract: The paper gives evidence that the vocal activity of elephants varies with group size, composition and reproductive status, and that elephants' Calling patterns could therefore provide the basis for a remote monitoring system. We examined a 3-week set of array-based audio recordings of savanna elephants (Loxodonta africana), searching for diagnostic acoustic parameters. An acoustic array made it possible to locate recorded sounds and attribute the calls to particular elephants or elephant groups. Simultaneous video recordings made it possible to document visible behaviour and roughly correlate it with vocalizations. We compared several measures of call density in elephant groups containing up to 59 individuals, and found that rates of calling increased with increasing numbers of elephants. We divided all call events into three structural types (single-voice low-frequency calls, multiple-voice clustered low-frequency calls, and single-voice high frequency calls), and found that the incidence of these varies predictably with group composition. These results suggest the value of a network of listening systems in remote areas for the collection of information on elephant abundance and population structure.

Rasmussen, L.E., Greenwood, D.R., 2003. Frontalin: a chemical message of musth in Asian elephants (Elephas maximus). Chemical Senses 28, 433-446.
Abstract: Musth is an important male phenomenon affecting many aspects of elephant society including reproduction. During musth, the temporal gland secretions (as well as the urine and breath) of adult male Asian elephants (Elephas maximus) discharge a variety of malodorous compounds together with the bicyclic ketal, frontalin. In contrast, teenage male elephants in musth release a sweet-smelling exudate from their facial temporal gland. We recently demonstrated that the concentration of frontalin becomes increasingly evident as male elephants mature. In the present study, we demonstrate that behaviors exhibited towards frontalin are consistent and dependent on the sex, developmental stage and physiological status of the responding conspecific individual. To examine whether frontalin functions as a chemical signal, perhaps even a pheromone, we bioassayed older and younger adult males, and luteal- and follicular-phase and pregnant females for their chemosensory and behavioral responses to frontalin. Adult males were mostly indifferent to frontalin, whereas subadult males were highly reactive, often exhibiting repulsion or avoidance. Female chemosensory responses to frontalin varied with hormonal state. Females in the luteal phase demonstrated low frequencies of responses, whereas pregnant females responded significantly more frequently, with varied types of responses including those to the palatal pits. Females in the follicular phase were the most responsive and often demonstrated mating-related behaviors subsequent to high chemosensory responses to frontalin. Our evidence strongly suggests that frontalin, a well-studied pheromone in insects, also functions as a pheromone in the Asian elephant: it exhibits all of the determinants that define a pheromone and evidently conveys some of the messages underlying the phenomenon of musth. Department of Biochemistry and Molecular Biology, OGI School of Science and Engineering, Oregon Health & Science University, Beaverton, OR 97006-8921, USA. betsr@bmb.ogi.edu

Rasmussen, L.E., Lazar, J., Greenwood, D.R., 2003. Olfactory adventures of elephantine pheromones. Biochem Soc Trans 31 (Pt 1), 137-141.
Abstract: Understanding the linkage between behaviour of mammals in their natural environment and the molecular basis of their sensory modalities presents challenges to biologists. Our olfactory investigations that involve the largest extant land mammal, the elephant, offer some clues of how these events mesh in sequence. Proboscideans have developed a sophisticatedly organized society and they rank with primates and cetaceans with respect to cognitive abilities. Our studies of discrete, quantifiable pheromone-elicited behaviours demonstrate that Asian elephants utilize their olfactory senses during fundamental, life-strategy decisions, including mate choice, female bonding and male hierarchical sorting. How biologically relevant odorants traverse mucous interfaces to interact with cognate odorant receptors remains a basic question in vertebrate olfaction. We have partially tracked the molecular odour reception trail of behaviourally distinct pheromones, ( Z )-7-dodecenyl acetate and frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane), using approaches developed for insect studies and taking advantage of the extensive, highly mucoidal olfactory and vomeronasal systems that permit detailed investigations of pheromone-binding proteins. We have combined studies of quantifiable responses and behaviours with biochemical and biophysical investigations of the properties of protein-ligand complexes, their sequential pathways and associated protein-ligand fluxes. In the delineation of these sequential integrations of behavioural, biochemical and molecular events, we have discovered novel spatial and temporal adaptations in both the main olfactory and vomeronasal systems.

Rasmussen, L.E.L., Lazar, J., Greenwood, D.R., 2003. Olfactory adventures of elephantine pheromones. Biochemical Society Transactions 31.
Abstract: Understanding the linkage between behaviour of mammals in their natural environment and the molecular basis of their sensory modalities presents challenges to biologists. Our olfactory investigations that involve the largest extant land mammal, the elephant, offer some clues of how these events mesh in sequence. Proboscideans have developed a sophisticatedly organized society and they rank with primates and cetaceans with respect to cognitive abilities. Our studies of discrete, quantifiable pheromone-elicited behaviours demonstrate that Asian elephants utilize their olfactory senses during fundamental, life-strategy decisions, including mate choice, female bonding and male hierarchical sorting. How biologically relevant odorants traverse mucous interfaces to interact with cognate odorant receptors remains a basic question in vertebrate olfaction. We  have  partially tracked the molecular odour reception trail of behaviourally  distinct pheromones, (Z)-7-dodecenyl acetate and frontalin  (1,5-dimethyl-6,8 dioxabicyclo[3.2.1]octane), using approaches  developed for  insect studies and taking advantage of the extensive, highly mucoidal  olfactory and vomeronasal systems that permit detailed investigations  of  pheromone-binding proteins. We have combined studies of quantifiable responses and behaviours with biochemical and biophysical investigations of the properties of protein-ligand complexes, their sequential pathways and associated protein-ligand fluxes. In the delineation of these sequential integrations of behavioural, biochemical and molecular events, we have discovered novel spatial and temporal adaptations in both the main olfactory and vomeronasal systems.

Slade, B.E., Schulte, B.A., Rasmussen, L.E.L., 2003. Oestrous state dynamics in chemical communication by captive female Asian elephants. Animal Behaviour 65, 813-819.
Abstract: In many mammals, reproductive status is revealed through chemical cues in urine. The reproductive status of receivers may influence their interest in such signals. For social mammals that live in matrilineal groups, females may benefit by detecting the reproductive condition of herdmates. Responses to urine during oestrous cycles of senders and receivers are potential indicators of signal functions. We examined the chemosensory responses, first by four captive female Asian elephants, Elephas maximus, over their oestrous cycles to familiar follicular and luteal phase urine and second by 14 different female Asian elephants to unfamiliar conspecific follicular and luteal phase urine. We asked whether females could distinguish the reproductive state of another female as measured by their differential response to luteal-and follicular-phase urine. We further examined the influence of the receiver's reproductive status on response levels. Females responded more with specific tactolfactory trunk behaviours to follicular- than to luteal-phase urine, but only when the receiving female was in her follicular phase. Like their male conspecifics, Asian elephant females can detect changes in the reproductive state of conspecifics. The functional significance of this ability has yet to be determined but may be related more to the resource holding power of females in follicular phase than to a means for females to synchronize oestrous cycles. Such female-female communication may have important effects on social group dynamics.

Yappert, M.C., Rujoi, M., Borchman, D., Vorobyov, I., Estrada, R., 2003. Glycero- versus sphingo-phospholipids: correlations with human and non-human mammalian lens growth. Exp Eye Res 76, 725-734.
Abstract: The human lens differs from other mammalian lenses in its very slow growth and unusual phospholipid composition of its cell membranes. Dihydrosphingomyelins (DHSMs) make up about half of all phospholipids in adult human fiber membranes. In all other membranes, sphingomyelins(SMs) with a trans double bond in their backbone, are prevalent. In our quest to understand the biological implications of such elevated DHSM levels, we analyzed membranes from various regions of human, elephant, giraffe, polar bear, pig and cow lenses. The levels of DHSMs were minor in non-human lens membranes. A strong correlation was observed between growth rate and relative contents of phosphatidylcholines(PCs) in epithelia and outer cortical fibers. Sphingomyelins became increasingly predominant in differentiated fibers and this increase was age dependent. Indeed, nuclear fiber membranes of aged non-human mammals were composed, almost exclusively, of (SMs). Although human lens membranes followed comparable compositional trends, the magnitude of the changes was much smaller. We postulate that the high relative contents of DHSMs provide a biochemically inert matrix in which only small amounts of PCs and SMs and their metabolites, known to promote and arrest growth, respectively, are present. This compositional difference is proposed to contribute to the slow multiplication and elongation of human lens cells. Department of Chemistry, College of Arts and Sciences, University of Louisville, Louisville, KY 40292, USA. mcyapper@louisville.edu

Arnason, B.T., Hart, L.A., O'Connell-Rodwell, C.E., 2002. The properties of geophysical fields and their effects on elephants and other animals. J Comp Psychol 116, 123-132.
Abstract: Geophysical properties of acoustic, seismic, electric, and magnetic waveforms create opportunities and constraints for animals' communication and sensory monitoring of the environment. The geometric spreading of waves differs; at some frequencies, transmission is most efficient and has minimal noise. The spreading properties of seismic waves favor long-distance propagation for communication and environmental monitoring, and would benefit elephants (Elephas maximus and Loxodonta africana), such as in locating subsurface water. Extending C. E. O'Connell-Rodwell, B. T. Amason, and L. A. Hart (2000), a man jumping at 1.11 km propagated seismic waves at 10-40 Hz. Given the noise of lightning and the Schumann resonances, near field magnetic and electric transmission by animals would be most efficient around 1000 Hz.

Chandrasekharan, K., 2002. Elephant - an overview. Journal of Indian Veterinary Association Kerala 7, 8-11.

Chandrasekharan, K., 2002. Specific diseases of Asian elephants. Journal of Indian Veterinary Association Kerala 7, 31-34.
Abstract: The earliest writing describing the diseases of elephants in ancient literature said to be the works on "Gajasastra" (Elephantology) written in Sanskrit by authors like Gautama, Narada, Mrigacharma, Rajaputra and Vyasa. "Hasthyayurveda" a legendary book in Sanskrit written by a safe Palakapya deals with some diseases, treatment, desirable and undesirable points of selection, management practices and some mythological aspects on the origin of elephants. The earliest book in English dealing with diseases of elephants seems to be that of W. Gilchrist "A practical treatise on the treatment of diseases of elephants" published in 1848. Later Slym (1873), Sanderson (1878), Steel (1885), Evans (1910), Herpburn (1913), Milroy (1922), Ptaff (1940), Ferrier (1947), Utoke Gale (1974), Chandrasekharan (1979) and Panicker (1985) have documented their findings on the incidence, etiology and control of diseases of Asian elephants.

Johnson, E.W., Rasmussen, L., 2002. Morphological characteristics of the vomeronasal organ of the newborn Asian elephant (Elephas maximus). Anatomical Record 267, 252-259.
Abstract: The 6-week-old Asian elephant (Elephas maximus) has a well-documented precocious flehmen response to pheromones, suggesting that the pheromone-detecting vomeronasal organ (VNO) is functional very early in the life of this species. To further document this, the VNOs of two newborn elephants were examined in situ and analyzed by light microscopy (LM) to ascertain their structural maturity at birth. A tubular, cartilage-encased VNO was located along the anterior base of each side of the nasal septum. Its rostral end was connected to a duct to the roof of the mouth; the caudal end was attached to a well-defined vomeronasal nerve projecting toward the brain. LM revealed distinctive differences in the mucosae bordering the horseshoe-shaped lumen: a concave, sensory mucosa, and a convex, nonsensory mucosa. Small groups of receptor neurons were observed among ciliated columnar cells in the sensory epithelium. Numerous unmyelinated nerve bundles and blood vessels filled the underlying lamina propria (LP) and a small section of the vomeronasal nerve was conspicuous at one edge. The nonsensory mucosa manifested a thinner epithelium that principally consisted of ciliated columnar cells, some of which showed a granular cytoplasm, and a conspicuous row of basal cells. The LP was replete with acinar glands and ducts that opened into the lumen. This study shows that the VNO of the newborn elephant has reached an advanced stage of structural maturity, closely resembling that of the adult. Its composition supports the view that flehmen at 6 weeks delivers pheromones to a functional VNO.

Lazar, J., Greenwood, D.R., Rasmussen, L.E., Prestwich, G.D., 2002. Molecular and functional characterization of an odorant binding protein of the Asian elephant, Elephas maximus: implications for the role of lipocalins in mammalian olfaction. Biochemistry 41, 11786-11794.
Abstract: The sex pheromone present in the pre-ovulatory urine of female Asian elephants is the simple lipid (Z)-7-dodecen-1-yl acetate (Z7-12:Ac). Using radiolabeled probes, we have identified a pheromone binding protein that is abundant in the mucus of the trunk; this protein is homologous to a class of lipocalins known as odorant binding proteins (OBPs). To test five previously proposed roles for the OBP in chemosensory perception, we determined the equilibrium dissociation constant of the OBP-pheromone complex, as well as the association and dissociation rates. Using a mathematical model in conjunction with experimental data, we suggest that the binding and release of the pheromone by the OBP are too slow for the OBP to function in transporting the pheromone through the mucus that covers the olfactory sensory epithelium. Our data indicate that the elephant OBP only modestly increases the solubility of the pheromone in the mucus. Our results are most consistent with the notion that elephant OBP functions as a scavenger of the pheromone and possibly other ligands, including odorants. In light of these findings, and published results for other mammalian OBP-ligand complexes, a general model for the role of OBPs in mammalian olfaction is proposed. Moreover, the potential implications of these findings for interaction of Z7-12:Ac with insect antennal proteins are discussed.

Nayar, K.N.M., Chandrasekharan, K., Radhakrishnan, K., 2002. Management of surgical affections in captive elephants. Journal of Indian Veterinary Association Kerala 7, 55-59.

Rasmussen, L.E., Wittemyer, G., 2002. Chemosignalling of musth by individual wild African elephants (Loxodonta africana): implications for conservation and management. Proc R Soc Lond B Biol Sci 269, 853-860.
Abstract: Elephants have extraordinary olfactory receptive equipment, yet this sensory system has been only minimally investigated in wild elephants. We present an in-depth study of urinary chemical signals emitted by individual, behaviourally characterized, wild male African elephants, investigating whether these compounds were the same, accentuated, or diminished in comparison with captive individuals. Remarkably, most emitted chemicals were similar in captive and wild elephants with an exception traced to drought-induced dietary cyanates among wild males. We observed developmental changes predominated by the transition from acids and esters emitted by young males to alcohols and ketones released by older males. We determined that the ketones (2-butanone, acetone and 2-pentanone, and 2-nonanone) were considerably elevated during early musth, musth and late musth, respectively, suggesting that males communicate their condition via these compounds. The similarity to compounds released during musth by Asian male elephants that evoke conspecific bioresponses suggests the existence of species-free 'musth' signals. Our innovative techniques, which allow the recognition of precise sexual and musth states of individual elephants, can be helpful to managers of both wild and captive elephants. Such sampling may allow the more accurate categorization of the social and reproductive status of individual male elephants.

Rasmussen, L.E., Riddle, H.S., Krishnamurthy, V., 2002. Mellifluous matures to malodorous in musth. Nature 415, 975-976.
Abstract: Male Asian elephants in musth--an annual period of heightened sexual activity and intensified aggression--broadcast odoriferous, behaviourally influential messages from secretions of the temporal gland. From our observations in the wild, together with instantaneous chemical sampling and captive-elephant playback experiments, we have discovered that young, socially immature males in musth signal their naivety by releasing honey-like odors to avoid conflict with adult males, whereas older musth males broadcast malodorous combinations to deter young males, facilitating the smooth functioning of male society. As elephant--human conflicts can upset this equilibrium, chemically modulating male behaviour may be one way to help the conservation of wild elephants.

Rasmussen, L.E.L., Riddle, H.S., Krishnamurthy, V., 2002. Mellifluous matures to malodorous in musth; Mood-altering secretions by excited male elephants smooth out social interactions. Nature 415, 975-976.

Sarma, K.K., 2002. Treatment of descemetocele in a captive elephant – A report. The North-East Veterinarian 1, 6-7.

Singh, V.N., 2002. Symptomatic study of haemorrhagic septicaemia in elephant in Mudumalai Wildlife Sanctuary, Tamil Nadu. Indian Forester 128, 1089-1100.
Abstract: Symptoms of haemorrhagic septicaemia, a dreaded disease in elephant is recorded in this study which reveals systematic spread of Oedema from jowl to throat, neck, brisket, abdomen and perenical regions. It also records the changes in character/colour of dung, urine, eye, tongue, trunk, body temperature, feeding habit and body condition along with treatment given to cure the disease.

Tongwongsa, S., Diskul, M.L.P., Kanchanapangka, S., Mahasawangkul, S., Lungka, G., Angkswanich, T., 2002. The use of an etorphine-acepromazine cocktail for immobilization and diprenorphine as it's antagonist in an elephant (Elephas maximus indicus). Thai Journal of Veterinary Medicine 32, 45-51.
Abstract: Etorphine hydrochloride (2.45 mg/ml) in combination with acepromazine maleate (10 mg/ml) is a very potent neuroleptanalgesic. The drug principally affects psychomotor activities. With a bundle of roughage still in his mouth, Plai Kum-Sand, a 3400 kgs, bull elephant, 35 years of age lay down 6 minutes after an intramuscularly injection. In lateral recumbency and snoring, the heart rate was 44 beats/minute with respiration at 4 breaths/minute. This heavy level of sedation was reversed quickly and successfully using 9.78 mg of the antidote, diprenorphine hydrochloride intravenously, 18 minutes after anaesthetic challenge. The bull opened his eyes 2 minutes afterward. He moved, stood upright, and started nibbling food 6 minutes 30 seconds after diprenorphine administration.

Tuntivanich, P., Soontornvipart, K., Tuntivanich, N., Wongaumnuaykul, S., Briksawan, P., 2002. Conjunctival microflora in clinically normal Asian elephants in Thailand. Veterinary Research Communications 26, 251-254.
Abstract: The objective of the study is to determine the population of microbial flora present in the healthy conjunctival sacs of elephants in Thailand. 44 elephants with normal eyes were studied. Of the 79 swabs cultured, 63 (88.8%) were positive for aerobic bacteria or yeasts, while no organisms were isolated from 16 eyes (11.2%). Gram-positive organisms, predominantly Staphylococcus spp. and Corynebacterium spp., accounted from more then 50% of the total number of isolates. Acinetobacter lwoffii was the main Gram -negative bacterium identified. The presence of yeast was also evident.

Tuntivanich, P., Soontornvipart, K., Tuntivanich, N., Wongaumnuaykul, S., Briksawan, P., 2002. Schirmer tear test in clinically normal Asian elephants. Veterinary Research Communications 26, 297-299.
Abstract: The objective of the study was to evaluate normal tear production in captive Asian elephants (Elephas maximus) in Thailand. 44 elephants (80 eyes) were studied. The mean value for a 1-minute Schirmer tear test (STT), without topical anaesthesia, was 34.3±1.7 mm/min, with a range of 14-70 mm/min. There was no significant difference between males and females. STT values varied with age, being lowest in the 0-20 year age group and highest in the 41-60 year age group.

Groo, M., 2001. The elephant listening project. AWI (Animal Welfare Institute?) quarterly 50, 10.

Hart, L.A., Arnason, B.T., O'Connell-Rodwell, C.E. Bioseismic communication mechanisms in elephants and rhinoceroses. A Research Update on Elephants and Rhinos; Proceedings of the International Elephant and Rhino Research Symposium, Vienna, June 7-11, 2001.  42-46. 2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding

McComb, K., Moss, C., Durant, S.M., Baker, L., Sayialel, S., 2001. Matriarchs as repositories of social knowledge in African elephants. Science 292, 491-494.
Abstract: Despite widespread interest in the evolution of social intelligence, little is known about how wild animals acquire and store information about social companions or whether individuals possessing enhanced social knowledge derive biological fitness benefits. Using playback experiments on African elephants (Loxodonta africana), we demonstrated that the possession of enhanced discriminatory abilities by the oldest individual in a group can influence the social knowledge of the group as a whole. These superior abilities for social discrimination may result in higher per capita reproductive success for female groups led by older individuals. Our findings imply that the removal of older, more experienced individuals, which are often targets for hunters because of their large size, could have serious consequences for endangered populations of advanced social mammals such as elephants and whales.

Rasmussen, L.E.L., Riddle, H.S. Musth in Teenage Male Asian Elephants (Elephas maximus): The What & the Why of their Chemical Signals. A Research Update on Elephants and Rhinos; Proceedings of the International Elephant and Rhino Research Symposium, Vienna, June 7-11, 2001.  110. 2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding

Rasmussen, L.E.L., Krishnamurthy, V., 2001. Urinary, temporal gland and breath odors from Asian elephants of Mudumalai National Park. Gajah 20, 1-7.

Rasmussen, L.E.L., 2001. Source and cyclic release pattern of (Z)-7-dodecenyl acetate, the pre-ovulatory pheromone of the female Asian elephant. Chemical Senses 26, 611-623.
Abstract: Female Asian elephants (Elephas maximus) release a pre-ovulatory urinary pheromone, (Z)-7-dodecenyl acetate (Z7-12:Ac), to signal males of their readiness to mate. Z7-12:Ac is quantitatively elevated during the follicular stage of oestrus, reaching maximum concentrations just prior to ovulation, as demonstrated by two complementary headspace techniques: (1) evacuated canister capture followed by cryogenic trapping and (2) solid phase microextraction (SPME) used prior to gas chromatography/mass spectrometry (GC/MS). These patterns were coincident with observed male behaviours and were consistent with biochemical and binding properties of the active ligand, including optimal binding pH. To release maximum amounts of Z7-12:Ac for quantitation, serum and urine samples from three mature female Asian elephants in their luteal and follicular stages of several oestrous cycles were subjected to heat and pH changes and were then treated with protease prior to SPME-GC/MS analyses. When the post-luteal serum progesterone concentrations declined to baseline levels, Z7-12:Ac became detectable in the female urine. Throughout the follicular stage, pheromone concentrations increased linearly with no apparent relationship to the two serum luteinizing hormone peaks. Pre-ovulatory urine also contained related compounds, including (Z)-7-12-dodecenol. The relative amount of this alcohol increased relative to acetate during long-term storage, with a proportional reduction in bioactivity. Z7-12:Ac was not detected in mucus samples from the urogenital tract. A potential precursor of Z7-12:Ac was identified in liver homogenates from female elephants in the follicular stage.  Erratum in: Chem Senses 2001 Sep;26(7):935

Schulte, B.A., Slade, B.E., Rasmussen, L.E.L. The Trunk and Tail of Elephant Communication: Studies on Captive Asian Elephants. A Research Update on Elephants and Rhinos; Proceedings of the International Elephant and Rhino Research Symposium, Vienna, June 7-11, 2001.  286. 2001. Vienna, Austria, Schuling Verlag. 2001.
Ref Type: Conference Proceeding

Langbauer, W.R., Jr., 2000. Elephant Communication. Zoo Biology 19, 425-445.
Abstract: Elephants live in a complex society where both long- and short-distance communication play an important role in the ability to locate mates and to maintain intra- and inter-group cohesion. Elephants use a variety of sensory channels in ways both complementary and redundant to achieve this communication, as well as to advertise physiological states, allow reliable assessment of intent, and engage in other behaviors of group living. The majority of long distance communication is probably via infrasonic vocalizations and chemical signals, while vocalizations, chemical signals, and visual and tactile displays all play a role in short distance interactions. While much is known about the general social and behavioral contexts of elephant communication signals, more work needs to be done to elucidate the specific role of many signals. The next critical step in the study of the elephant's vocal repertoire is to collect and categorize the calls of known individuals for later playback experiments to confirm their function. In addition, the way that physiological state affects chemical signals and vice versa is worthy of further study, as is the role of chemical, acoustic, and perhaps seismic communication in long-distance communication. Tactile and visual displays have been qualitatively described, but there is a need to quantifying their role in the dynamic behaviors (such as conflict management) that maintain elephant society. Finally, the way signals from multiple sensory channels interact has been little studied and provides a rich arena for future work.

McComb, K., Moss, C., Sayialel, S., Baker, L., 2000. Unusually extensive networks of vocal recognition in African elephants. Animal Behaviour 59, 1103-1109.
Abstract: Research on acoustic communication has often focused on signaling between territorial individuals or static neighboring groups. Under these circumstances, receivers have the opportunity to learn to recognize the signals only of the limited number of conspecifics with which they are in auditory contact. In some mammals, however, social units move freely with respect to one another and range widely, providing individuals with opportunities to learn to recognize the signals of a wide range of conspecifics in addition to those of their immediate neighbors. We conducted playback experiments on African elephants, Loxodonta africana, in Amboseli National Park, Kenya, to determine the extent to which adult female elephants, which have a highly fluid social system, can recognize others in the population through infrasonic contact calls. Female elephants could distinguish the calls of female family and bond group members from those of females outside of these categories; moreover, they could also discriminate between the calls of family units further removed than bond group members, on the basis of how frequently they encountered them. We estimated that subjects would have to be familiar with the contact calls of a mean of 14 families in the population (containing around 100 adult females in total), in order to perform these discriminations. Female elephants thus appear to have unusually extensive networks of vocal recognition, which may prove to be typical of long-lived species that have both fluid social systems and the means for long-distance vocal communication.

McCowan, B. Developing a Quantitative Method for Analyzing Infrasonic Vocalizations in Elephants. Elephants: Cultural, Behavioral, and Ecological Perspectives; Program and Abstracts of the Workshop.  15. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding

O'Connell-Rodwell, C., Arnason, B., Hart, L. The Seismic Propagation of Elephant Low Frequency Vocalizations and Possible Detection Mechanisms. Elephants: Cultural, Behavioral, and Ecological Perspectives; Program and Abstracts of the Workshop.  18. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding

O'Connell-Rodwell, C.E., Arnason, B.T., Hart, L.A., 2000. Seismic properties of Asian elephant (Elephas maximus) vocalizations and locomotion. J Acoust Soc Am 108, 3066-3072.
Abstract: Seismic and acoustic data were recorded simultaneously from Asian elephants (Elephas maximus) during periods of vocalizations and locomotion. Acoustic and seismic signals from rumbles were highly correlated at near and far distances and were in phase near the elephant and were out of phase at an increased distance from the elephant. Data analyses indicated that elephant generated signals associated with rumbles and "foot stomps" propagated at different velocities in the two media, the acoustic signals traveling at 309 m/s and the seismic signals at 248-264 m/s. Both types of signals had predominant frequencies in the range of 20 Hz. Seismic signal amplitudes considerably above background noise were recorded at 40 m from the generating elephants for both the rumble and the stomp. Seismic propagation models suggest that seismic waveforms from vocalizations are potentially detectable by instruments at distances of up to 16 km, and up to 32 km for locomotion generated signals. Thus, if detectable by elephants, these seismic signals could be useful for long distance communication.

Rasmussen, L.E.L., Goodwin, T.E., 2000. Initial studies on the source and cyclic release pattern of (Z)-7-dodecenyl acetate, the preovulatory pheromone of female Asian elephants. Chemical Senses 25, 603.

Rasmussen, L.E.L. Wild and Non-wild Elephants: How Two Modes of Olfaction and a Multitude of Chemical Signals and Pheromones Influence Elephant Behavior. Elephants: Cultural, Behavioral, and Ecological Perspectives; Program and Abstracts of the Workshop.  19-20. 2000. Davis, CA. 2000.
Ref Type: Conference Proceeding

Rasmussen, L.E.L., Krishnamurthy, V., 2000. How chemical signals integrate Asian elephant society: the known and the unknown. Zoo Biology 19, 405-423.
Abstract: The importance of chemical senses to elephants was recognized in anecdotal observations by ancient humans. Modern scientific tools, such as molecular biological techniques, highly sensitive gas chromatographic/mass spectrometric instrumentation, and statistically valid ethological methods, have allowed the study of real events of chemical communication between elephants. Such communication encompasses long- and short-range navigation, relationship recognition, and inter- and intra-sexual exchange of reproductive condition, metabolic state, and social status. Asian elephants emit large amounts of complex chemical mixtures in breath and urine, and in secretions from the temporal gland, inter-digital glands, and ears. Some emitted chemicals originate in blood and may be metabolic products; others are secretory products, at times apparently under hormonal control. The wide variety of emitted compounds includes hormones, proteins, and volatile compounds; selected volatile ketones and an acetate ((Z)-7-dodecenyl acetate) function as chemical signals and a pheromone, respectively. Some of these specific chemicals identified in emissions from Asian elephants dwelling in the United States have been found to be present in the exudates from elephants in India. This similarity is demonstrable for three metabolic conditions: pregnancy in females and pre- and post-musth males. Future chemical communication studies on male elephants should focus on musth and its relevance to reproduction and male social structures. Such investigations should include hormones, metabolites, brain chemistry, and possible primer pheromones. For females, the factors influencing possible estrous synchrony, what role primer pheromones play in female reproduction, how chemical signals influence social behavior, and whether luteinizing hormone influences pheromone production are among remaining fundamental questions.

Riddle, H.S., Riddle, S.W., Rasmussen, L.E.L., Goodwin, T.E., 2000. First disclosure and preliminary investigation of a liquid released from the ears of African elephants. Zoo Biology 19, 475-480.
Abstract: This report is the first documentation, both behaviorally and chemically, of a phenomenon observed among African elephants (Loxodonta africana) whereby a sudden, often stream-like discharge of liquid is seen from the auricular orifice.  During this initial investigation, multiple samples of the fluid have been collected for analysis of physical properties and components.  Trace organic chemicals which are apparently of elephant origin have been identified in the ear liquid, and the aqueous nature of the liquid has been demonstrated.  The continuing objectives of this work and related studies are to determine the specific source of the liquid with particular focus on a search for auricular glands, to further characterize potential conspecific chemical signals, and to document more precisely particular social situations when this phenomenon occurs.

 1999. Equine Medicine and Surgery. Mosby, St. Louis MO USA.

Goodwin, T.E., Rasmussen, E.L., Guinn, A.C., McKelvey, S.S., Gunawardena, R., Riddle, S.W., Riddle, H.S., 1999. African elephant sesquiterpenes. J Nat Prod 62, 1570-1572.
Abstract: GC-MS analysis of extracts from temporal gland secretions of an African elephant has revealed the presence of several farnesol-related sesquiterpenes. Among these are (E)-2, 3-dihydrofarnesol (3), a bumblebee pheromone not seen before in mammals, and a rare component of a Greek tobacco, drimane-8alpha, 11-diol (4), never observed before in an animal.

Kodikara, D.S., deSilva, N., Makuloluwa, C.A.B., Gunatilake, M., 1999. Bacterial and fungal pathogens isolated from corneal ulcerations in domesticated elephants (Elephas maximus maximus) in Sri Lanka. Veterinary Ophthalmology 2, 191-192.
Abstract: Of 140 elephants of different ages and both sexes, 36 animals (25.7%) had evidence of keratitis, corneal ulcers, corneal opacities and some had foreign bodies in their eyes. Nine elephants (6.4%) had lesions in both eyes (6.41%). Cultures for both bacteria and fungi were obtained from 26 corneal ulcers, including the nine elephants with bilateral lesions. The other 10 animals could not be restrained for sample collection. Swabs from the normal corneas of an additional 20 elephants without signs of any ophthalmic diseases were also collected. 23 of the 35 (65.71%) samples from affected corneas yielded bacterial pathogens, and 14 (40%) also had fungal isolates. None of them yielded a fungal isolate alone. The predominant bacteria isolated were Staphylococcus aureus, beta haemolytic streptococci and coliforms. Fusarium, Cladosporium, Curvularia and Aspergillus species were the primary fugal isolates. No bacteria or filamentous fungi were isolated from the eyes with the normal corneas. Microbial identification including that of fungal isolates is suggested in the management of infective corneal diseases in elephants.

Kuntze, A., 1999. Oral and nasal diseases of elephants. In: Fowler, M.E., Miller, R.E. (Eds.), Zoo and Wild Animal Medicine: Current Therapy 4. W.B. Saunders, Philadelphia, PA,USA, pp. 544-546.

O'Connell, C.E., Hart, L.A., Arnason, B.T., 1999. Comments on "Elephant hearing". Journal of the Acoustical Society of America 105, 2051-2052.
Abstract: See "Elephant hearing" [J. Acoust. Soc. Am. 104, 1122-1123 (1998)]

Poole, J.H., 1999. Signals and assessment in African elephants: evidence from playback experiments. Animal Behaviour 58, 185-193.
Abstract: A series of playback experiments using two elephant vocalizations, the 'musth rumble' and the 'oestrous call', was carried out in Amboseli National Park to examine signaling and assessment in African elephants, Loxodonta africana. In response to the musth rumble of a high-ranking male other musth males approached the speaker aggressively, whereas nonmusth males walked away from the stimulus. The call of an oestrous female, too, attracted musth males who approached the speaker rapidly, while nonmusth males listened and then walked away. Females listened and often showed considerable interest in the musth rumbles of males, approaching the speaker and sometimes responding by vocalizing and or secreting from the temporal glands. The experiments bear out earlier observational data and game theory predictions which suggest that by being in or out of musth a male may be conveying information about the relative value he places on contesting his dominance rank and his access to oestrous females. When not visibly in musth, a male may be indicating his intention not to contest access to oestrous females.

Rasmussen, L.E.L., Perrin, T.E., 1999. Physiological correlates of musth: lipid metabolites and chemical composition of exudates. Physiology and Behavior 67, 539-549.
Abstract: Physiological changes related to lipid metabolism, behaviour and chemicals released in body exudates were studied during musth in the Asian elephant (Elephas maximus) as a case study. During musth, changes in serum testosterone and triglyceride concentrations followed similar patterns, with the former increasing sooner than the latter. Deviant behaviour increased during changing androgen levels. The observed high concentrations of testosterone were positively and significantly correlated with increased triglycerides. Lipase activity elevated significantly immediately before and after musth. Blood pH increased significantly in alkalinity. Urine and temporal gland secretions released variable amounts of compounds, some of which may be chemical signals. During musth, temporal gland and urinary exudates demonstrated increased acetone and other ketones indicative of lipid metabolic alterations. Large quantities of nonmethane hydrocarbons, especially 2-butanone, were released from the seemingly dry orifice of the temporal gland before the start of over musth and before maximum blood elevations were observed; isoprene release was similar. However, maximal acetone levels occurred simultaneously in blood, temporal gland secretions, and urine. Metabolically, musth is a series of interwoven, changing stages of increasing and decreasing hormones and lipid-related constituents. Released chemicals can be quantitatively related to these internal physiological events; some observed behaviours appear to result from altered chemical signals.

Rasmussen, L.E.L., Prestwich, G.D., 1999. Initial molecular studies of (Z)-7-dodecenyl acetate as a mammalian sex pheromone. Chemical Senses 24, Abstract # 365.

Rasmussen, L.E.L., 1999. Evolution of chemical signals in the Asian elephant, Elephas maximus: behavioural and ecological influences. Journal of Biosciences 24, 241-251.
Abstract: In antiquity, the Asian elephant, Elephas maximus, gradually spread southward and eastward to become a successfully surviving, ecologically dominant megaherbivore in the tropical environment of south-east Asia. The changing physical environment forced dynamic fluxes in its social structure and altered its metabolism. Such events shaped the production and ultimately the stability of certain chemicals released by body effluvia. Some of these chemicals took on significance as chemical signals and/or pheromones. This article demonstrates by experimental and observational evidence, and hypothesizes based on speculative reasoning, how and why specific chemical signals evolved in the modern Asian elephant. Evidence, including the functional criteria required by elephant social structure and ecology, is presented for the hypothesis that the recently identified female-emitted, male-received sex pheromone, (Z)-7-dodecenyl acetate evolved first as a chemical signal. Subsequently, the cohesiveness and harmony of small, matriarchally-led female groups were strengthened by a female-to-female chemical signal, recently defined behaviourally. The looser societal structure of freer, roaming males also became bounded by chemical signals; for the males, breath and temporal gland emissions, as well as urinary ones function in chemical signaling. Basic knowledge about elephant chemical signals is now linking chemical information to behaviour and beginning to demonstrate how these signals affect elephant social structure and enable the species to cope with environmental changes.

Rasmussen, L.E.L., Schulte, B.A., 1999. Ecological and biochemical constraints on pheromonal signaling systems in Asian elephants and their evolutionary implications. In: Johnston, R.E., Muller-Schwarze, D., Sorenson, P.W. (Eds.), Advances in Chemical Communication in Vertebrates 8. Kluwer/Academic/ Plenum Press, pp. 49-62.
Abstract: The Asian elephant is an unusual example of how intraspecies chemical communication helps maintain societal cohesiveness within familial and herd units. The amount of multi-directional chemical communication is surprising, because long-lived elephants have a highly organized society, are capable of trans-generational passage of information, possess a sophisticated vocalization system, and are capable of complex learning and tool use. This paper discusses the ecological, behavioral, and biochemical aspects of chemical signals in elephants from an evolutionary perspective. Diverse bodily emissions are utilized as intraspecies chemical signals (including pheromones), often with imposed biochemical constraints. In this chapter, chemosignals released from the temporal gland secretions and breath of male Asian elephants in musth and a urinary female-to-male preovulatory pheromone are utilized as examples of these concepts. Furthermore, specific behavioral and biochemical studies with (Z)-7-dodecenyl acetate (a female-to-male urinary sex pheromone) demonstrate that social context significantly influences responsivity (demonstrated by field studies in Myanmar) and that additional biochemical requirements, perhaps lipocalin-like proteins, may be required for full bioactivity. The remarkable convergent evolution of (Z)-7-dodecenyl acetate, both structurally and functionally, in elephants and Lepidoptera, allows the use in elephant studies of effective biochemical tools developed for insect investigations. This convergence of chemical signaling systems of elephants and insects has several interesting implications.

Rasmussen, L.E.L., 1999. Elephant Olfaction. ChemoSenses 2, 4-5.

Schulte, B.A., Rasmussen, L.E., 1999. Signal-receiver interplay in the communication of male condition by Asian elephants. Animal Behaviour 57, 1265-1274.
Abstract: Signal design and meaning are dependent on the condition of the sender and receiver as well as the response of the receiver. This study examined (1) whether female Asian elephants, Elephas maximus, can distinguish between a conspecific male in musth and nonmusth states using urinary signals, (2) how the oestrous condition of the female affects discrimination, and (3) correlation of female responses with the testosterone level of the male. Musth is a rut-like state displayed by healthy adult male elephants. Males in musth dominate nonmusth males and may be preferred by females as mates. Urine was collected from two captive male Asian elephants during nonmusth periods and from one of these males during times of musth. Samples of musth and nonmusth urine and control liquids were placed in an elephant enclosure weekly for 16 weeks, the length of a female oestrous cycle. Primary response behaviours were approach and four trunk-tip motions, namely sniff, check, place and flehmen. Musth urine consistently elicited greater responses than nonmusth and control samples. Females were more responsive during their follicular (sexually  receptive) than luteal (unreceptive) stages of oestrus. Furthermore, females appeared to be sensitive to the degree of musth as responses increased with rising serum testosterone levels of the male donor. Chemical signals from males are a likely source of honest signals related to status and reproductive condition. Female elephants appear capable of detecting differences in a male based upon urinary chemosignals.

Silver, W., 1999. Chemesthesis: The burning questions. Chemosense 2.

Krzywicki, Z., 1998. Surgical treatment of the bilateral nictitans prolapse in an elephant. Magazyn Weterynaryjny 7, 29-30.

Payne, K., 1998. Silent Thunder : in the presence of elephants. Simon & Schuster, New York.

Rasmussen, B., 1998. The Chemical Identification of a Preovulatory Pheromone: A Reproductive Chemosignal from Female to Male Asian Elephants. Journal of the Elephant Managers Association 7, 52-56.

Rasmussen, L.E.L., Schulte, B.A., 1998. Chemical signals in the reproduction of Asian and African elephants. Animal Reproduction Science 53, 34.

Rasmussen, L.E.L., 1998. Chemical communication: An integral part of functional Asian elephant (Elephas maximus) society. Ecoscience 5, 410-426.
Abstract: The matriarchally organized Asian elephant society is characterized by long-term stability and continuity. Flux within this society results from changing ecological conditions and the dynamics of its population. Its structure is influenced by age composition and physiological states within the female herd and by impinging influences of the peripheral males, especially during reproductive times. Recent behavioral studies of captive populations have substantiated older field studies and have demonstrated that chemical signals play a significant role in elephant society. Chemical investigations, based on previously substantiated behavioral interactions, have identified specific compounds or combinations of compounds in elephant emissions (especially urine, temporal gland secretions and breath) that retain bioactivity throughout chemical extractions and playback experiments, based on behavioral and/or chemosensory responses. Chemosensory neuroreceptive systems in Asian elephants are reviewed, as well as behavioral and chemosensory effects of whole exudate chemical signals on lifestyles, especially related to mating. Several discrete and composite chemical signals have been deciphered in elephants, one of which is a preovulatory female-to-male pheromone, (Z)-7-dodecen-1-yl acetate. This pheromone and other recently described or potential chemical signals are compared to compounds in insect pheromone blends. Such knowledge of the chemical ecology of the Asian elephant has potentially important implications for conservation.

Rasmussen, L.E.L., Lazar, J., Greenwood, D., Feng, L., Prestwich, G.D., 1998. Initial characterizations of secreted proteins from Asian elephants that bind the sex pheromone, (Z)-7- dodecenyl acetate. Chemical Senses 23, 591.

Rasmussen, L.E.L., Schulte, B.A., 1998. Chemical signals in the reproduction of Asian (Elephas maximus) and African (Loxodonta africana) elephants. Animal Reproduction Science 53, 19-34.
Abstract: Asian (Elephas maximus) and African (Loxodonta africana) elephants exhibit polygynous mating that involves female choice of mates and male-male competition for access to females. Chemical signals mediate intersexual and intrasexual interactions associated with reproduction. The need for reliable and honest signals is accentuated by the markedly different social structure of adult males and females. Adult female elephants live in matriarchal herds consisting of a dominant female and several generations of offspring. Adult males are solitary or travel with other males except during breeding periods. Because females have a long 16-week oestrous cycle with a brief 1-week receptive period and a 4-5 year interval between births, a sexually active female is a limited resource. Asian elephant females advertise a forthcoming ovulation by releasing (Z)-7-dodecen-1-yl acetate in their urine during the preovulatory period. African elephants probably produce a sex pheromone as well. Females regularly contact the ano-genital region of other females and show heightened chemosensory responsiveness to urine during the follicular phase. The physiological impacts of this ability to detect reproductive condition (e.g. possible synchronizing or suppressing of oestrus) are uncertain. Males experience an annual period of heightened aggressiveness and highly elevated testosterone concentrations known as musth. Males secrete fluid copiously from their temporal gland and dribble strongly odoriferous urine during musth. Females appear to prefer musth males as mates, and captive Asian females exhibit greater chemosensory responses to urine from males in musth than not. Males in musth are competitively dominant to all other males, even those larger than themselves. Nonmusth males avoid males in musth, and captive Asian bulls show greater interest in musth than nonmusth urine. In captivity subordinate Asian females back away from musth secretions, and females with calves sometimes display protective behaviour. Clearly, chemical signals play an important role in communication by elephants between and within the sexes. Further work is needed to identify more of these chemical messengers and to understand their complete function in mediating reproductive interactions in the elephant social system.

Dehnhardt, G., Friese, C., Sachser, N., 1997. Sensitivity of the trunk of Asian elephants for texture differences of actively touched objects. Zeitschrift fuer Saeugetierkunde 62, 37-39.

Heffner, R.S., 1997. Comparative study of sound localization and its anatomical correlates in mammals. Acta Otolaryngol Suppl 532, 46-53.
Abstract: One of the fundamental features of hearing is the ability to localize the sources of sounds, particularly brief sounds, which may warn of nearby animals. Yet not all mammals localize sound equally well with threshold acuity ranging from about 1 degree for elephants and humans to more than 25 degrees for gerbils and horses and a near absence of localization in some subterranean species. During the past decade evidence has accumulated that this variation cannot be accounted for simply by the availability of the physical cues for locus. Nor does it appear to be a function of an animal's lifestyle. Rather sound-localization acuity in mammals appears to be a function of the precision required of the visual orienting response to sound. Thus the neural integration of hearing and vision in cortex, as well as in multimodal subcortical structures, is a reflection of their behavioral integration and evolutionary coupling.

Larom, D., Garstang, M., Payne, K., Raspet, R., Lindeque, M., 1997. The influence of surface atmospheric conditions on the range and area reached by animal vocalizations. J Exp Biol 200 (Pt 3), 421-431.
Abstract: Low-level vertical changes in temperature and wind exert powerful and predictable influences on the area ensonified by animal vocalizations. Computer modelling of low-frequency sound propagation in measured atmospheric conditions predicts that the calls of the savanna elephant at these frequencies can have ranges exceeding 10 km and that the calls will be highly directional in the presence of wind shear. Calling area is maximized under temperature inversions with low wind speeds. Calling area changes substantially over 24 h periods; on any given day, the calling area undergoes an expansion and contraction which may be as large as one order of magnitude. This cycle is modulated by topography, regional weather patterns, seasonality and possibly by climate variation. Similar influences affect the somewhat higher-frequency calls of lions and may be a selective pressure towards their crepuscular and nocturnal calling behaviour. Coyotes and wolves, which also live in areas with strong and prevalent nocturnal temperature inversions, show similar calling patterns, maximizing their chances of being heard over the longest possible distances. The pronounced dawn and evening vocalization peaks in other animals including birds, frogs and insects may reflect the same influences in combination with other factors which selectively limit high-frequency sound propagation. Atmospheric conditions therefore need to be taken into account in many field studies of animal behaviour. A simplified method for estimating sound propagation during field studies is presented.

Meng, J., Shoshani, J., Ketten, D., 1997. Evolutionary evidence for infrasonic sound and hearing in proboscideans. J. Vert. Paleo. 17, 64A-65A.

O'Connell, C.E., Arnason, B.T., Hart, L.A., 1997. Seismic transmission of elephant vocalizations and movement. Journal of the Acoustical Society of America 102, 3124.

Rasmussen, L.E., Lee, T.D., Zhang, A., Roelofs, W.L., Daves, G.D.Jr., 1997. Purification, identification, concentration and bioactivity of (Z)-7-dodecen-1-yl acetate: sex pheromone of the female Asian elephant, Elephas maximus. Chemical Senses 22, 417-437.
Abstract: In their natural ecosystems, adult male and female Asian elephants, Elephas maximus, live separately. For several weeks prior to ovulation, female elephants release a substance in their urine which elicits a high frequency of non-habituating chemosensory responses, especially flehmen responses, from male elephants. These responses occur prior to, and are an integral part of, mating. Using bioassay-guided fractionation, quantitatively dependent on these chemosensory responses, a specific sex pheromone was isolated and purified by an alternating series of organic and/or aqueous extractions, column chromatography, gas chromatography and high-performance liquid chromatography. Using primarily 1H-proton nuclear magnetic resonance (NMR) spectrometry and gas chromatography-mass spectrometry (GC-MS) of the urine-derived pheromone and its dimethyl disulfide derivative, we determined the structure of the active compound to be (Z)-7-dodecen-1-yl acetate (Z7-12:Ac). Concentrations of Z7-12:Ac in the female urine increased from non-detectable during the luteal phase to 0.48 microgram/ml (0.002 mM) early in the follicular phase and to 33.0 micrograms/ml (0.146 mM) just prior to ovulation. Bioassays with commercially available authentic synthetic Z7-12:Ac, using 10 Asian male elephants at several locations in the US, demonstrated quantitatively elevated chemosensory responses that were robust during successive tests, and several mating-associated behaviors. Bioassays with Z7-12:Ac with adult male elephants dwelling in more natural social situations in forest camps in Myanmar revealed some differing contextual pre-mating behavioral components. The remarkable convergent evolution of this compound suggests that compounds identified in mammalian exudates that are also present in pheromone blends of insects should be re-evaluated as potential mammalian chemosignals.

Rasmussen, L.E.L., Gunawardena, R.A., Rasmussen, R.A., 1997. Do Asian elephants, especially males in musth, chemically signal via volatiles in breath? Chemical Senses 22, 775.

Rasmussen, L.E.L., Lee, T.D., Zhang, A., Roelofs, W.L., Daves, G.D., 1997. Purification, Identification, Concentration and Bioactivity of (Z)-7-Dodecen-1-yl Acetate: Sex Pheromone of the Female Asian Elephant, Elephas maximus. Chemical Senses 22, 417-437.
Abstract: In their natural ecosystems, adult male and female Asian elephants, Elephas maximus, live separately. For several weeks prior to ovulation, female elephants release a substance in their urine which elicits a high frequency of non-habituating chemosensory responses, especially flehmen responses, from male elephants. These responses occur prior to, and are an integral part of, mating. Using bioassay-guided fractionation, quantitatively dependent on these chemosensory responses, a specific sex pheromone was isolated and purified by an alternating series of organic and/or aqueous extractions, column chromatography, gas chromatography and high-performance liquid chromatography. Using primarily 1H-proton nuclear magnetic resonance (NMR) spectrometry and gas chromatography-mass spectrometry (GC-MS) of the urine-derived pheromone and its dimethyl disulfide derivative, we determined the structure of the active compound to be (Z)-7-dodecen-1-yl acetate (Z7-12:Ac). Concentrations of Z7-12:Ac in the female urine increased from non-detectable during the luteal phase to 0.48 ug/ml (0.002 mM) early in the follicular phase and to 33.0 ug/ml (0.146mM) just prior to ovulation. Bioassays with commercially available authentic synthetic Z7-12:Ac, using 10 Asian male elephants at several locations in the US, demonstrated quantitatively elevated chemosensory responses that were robust during successive tests, and several mating-associated behaviors. Bioassays with Z7-12:Ac with adult male elephants dwelling in more natural social situations in forest camps in Myanmar revealed some differing contextual pre-matching behavioral components. The remarkable convergent evolution of this compound suggests that compounds identified in mammalian exudates that are also present in pheromone blends of insects should be re-evaluated as potential mammalian chemosignals.

Poole, J., 1996. Coming of Age with Elephants: a Memoir. Hodder and Stoughton, New York.

Rasmussen, B., Schulte, B., 1996. A medley of chemical signals. Journal of the Elephant Managers Association 7, 61-64.

Rasmussen, L.E.L., Lee, T.D., Roelofs, W.L., Zhang, A., Daves, G.D., 1996. Insect pheromone in elephants. Nature 379, 1.

Rasmussen, L.E.L., Hall-Martin, A.J., Hess, D.L., 1996. Chemical profiles of African bull elephants, Loxodonta africana: physiological and ecological implications. Journal of Mammalogy 77, 422-439.
Abstract: This study reports concentrations of testosterone and dihydrotestosterone in both serum and temporal-gland secretion of male African elephant (Loxodonta africana), including radiocollared elephants, and identifies a spectrum of volatile components in the temporal-gland secretions. Androgens in the serum (testosterone and dihydrotestosterone) were measured in 111 adult male African elephants, ages 21-40 years, from two national parks in South Africa during several  years and seasons.  About one-fifth (18.6%) of these mature, male, African elephants exhibited dramatically increased concentrations of testosterone in serum characteristic of male Asian elephants during musth.  In Krueger National Park, six radiocollared male African elephants, ages 25-35 years, were tracked and serially samples for both serum and temporal-gland secretions during a 5-year period. Concentrations of testosterone in serum and temporal gland secretions were elevated cyclically at times when typical musth behaviors, including aggression, were observed.  This study reports the first chemical characterization of the volatile compounds of the temporal gland secretions from male African elephants in musth. It reveals many similarities between the chemical constituents of the temporal-gland secretions of these male African elephants and the compounds identified in male Asian elephants.  In addition, several compounds, not previously identified in temporal-gland secretions of African elephants, are described.  Such chemical data support the behavioral observations by ourselves and other researchers that male African elephants experience musth. Especially convincing are the concurrent hormonal and chemical data from the radiocollared males during episodic periods of behavioral musth. Implications of the incidence of musth in the past and present ecology of African elephants are discussed in view of the increasing compression within national parks.

Rasmussen, L.E.L., Munger, B.L., 1996. The sensorineural specializations of the trunk tip (finger) of the Asian elephant, Elephas maximus. Anatomical Record 246, 127-134.
Abstract: BACKGROUND: The dorsal extension of the tip of the trunk of Asian elephants (Elephas maximus), often referred to as "the finger," possesses remarkable mechanical dexterity and is used for a variety of special behaviors including grasping food and tactile and ultimately chemosensory recognition via the vomeronasal organ. The present study describes a unique sensory innervation of this specialized region of the trunk. METHODS: The tip of the dorsal aspect of the trunk is referred to as the trunk tip finger and has been studied grossly in 13 living elephants. One tip from a male Asian elephant was obtained for histologic study when it was accidentally severed. The tissue was fixed in 10% neutral buffered formalin, and portions were either sectioned frozen or embedded in paraffin and serial sectioned. Sections were stained with silver in both cases. RESULTS: The skin of the trunk tip finger differs from that of the surrounding areas; it contains a high density of free nerve endings, numerous convoluted branched small corpuscles, and vellus vibrissae that resemble vellus hairs, which do not protrude beyond the skin surface. The finger is thus densely innervated with three distinctive types of sensory terminals. Corpuscular receptors consist of small Pacinian corpuscles and convoluted branched simple corpuscles. Both are present in the superficial dermis. Abundant regular vibrissae are present in the skin surrounding the trunk tip finger. Short vibrissae that do not protrude from the skin surface, referred to as vellus vibrissae, are abundant in the finger tip. Both types of vibrissae are innervated by hundreds of axons resembling the mystacial vibrissae of rodents. Free nerve endings are numerous in the superficial dermis, often making intimate contact with the basal cells of rete pegs. CONCLUSIONS: The dorsal finger of the trunk tip of Asian elephants has a unique sensory innervation that resembles aspects of sensory innervation of mystacial skin of rodents or lip tissue of monkeys. This dense sensory innervation can be correlated with the tactile ability of these animals to use the trunk finger to grasp small objects for feeding and to insert chemically active samples into the ductal orifices of the vomeronasal organ for subsequent chemosensory processing.

Chandrasekharan, K., Radhakrishnan, K., Cheeran, J.V., Nair, K.N.M., Prabhakaran, T., 1995. Review of the Incidence, Etiology and Control of Common Diseases of Asian Elephants with Special Reference to Kerala. In: Daniel, J.C. (Ed.), A Week with Elephants; Proceedings of the International Seminar on Asian Elephants. Bombay Natural History Society; Oxford University Press, Bombay, India, pp. 439-449.
Abstract: Incidence, etiology, symptoms and control of specific and non-specific diseases of captive and wild elephants have been reviewed. Asian elephants have been observed to be susceptible to various parasitic diseases such as helminthiasis, trypanosomiasis and ectoparasitic infestations, bacterial diseases such as tetanus, tuberculosis, haemorrhagic septicemia, salmonellosis and anthrax, viral diseases such as foot and mouth disease, pox and rabies and non-specific diseases like impaction of colon, foot rot and corneal opacity. A detailed study extending over two decades on captive and wild elephants in Kerala, revealed high incidence of helminthiasis (285), ectoparasitic infestation (235), impaction of colon (169) and foot rot (125). Diseases such as trypanosomiasis (21), tetanus (8), tuberculosis (5) pox (2) and anthrax (1) were also encountered. The line of treatment against the diseases mentioned, have been discussed in detail.

Garstang, M., Larom, D., Raspet, R., Lindeque, M., 1995. Atmospheric controls on elephant communication. J Exp Biol 198 (Pt4), 939-951.
Abstract: Atmospheric conditions conducive to long-range transmission of low-frequency sound as used by elephants are found to exist in the Etosha National Park in Namibia during the late dry season. Meteorological measurements show that strong temperature inversions form at the surface before sunset and decay with sunrise, often accompanied by calm wind conditions during the early evening. These observations are used in an acoustic model to determine the sensitivity of infrasound to the effects of (a) the strength, thickness and elevation of temperature inversions, and (b) the growth and decay of an inversion typical of dry, elevated African savannas. The results suggest that the range over which elephants communicate more than doubles at night. Optimum conditions occur 1-2 h after sunset on clear, relatively cold, calm nights. At these times, ranges of over 10 km are likely, with the greatest amplification occurring at the lowest frequency tested. This strong diurnal cycle in communication range may be reflected in longer-lasting changes in weather and may exert a significant influence on elephant behaviour on time scales from days to many years.

Hemila, S., Nummela, S., Reuter, T., 1995. What middle ear parameters tell about impedance matching and high frequency hearing. Hear Res 85, 31-44.
Abstract: Acoustic energy enters the mammalian cochlea aided by an anatomical impedance matching performed by the middle ear. The purpose of this paper is to analyze the functional consequences of changes in scale of the middle ear when going from the smallest mammals to the largest. Our anatomical measurements in mammals of different sizes ranging from bats to elephants indicate that middle ear proportions are largely isometric. Thus the calculated transformer ratio is basically independent of animal size, a typical value lying between 30 and 80. Similarly, the calculated specific acoustic input impedance of the inner ear is independent of animal size, the average value being about 140 kPa s/m. We show that if the high frequency hearing limit of isometric ears is limited by ossicle inertia, it should be inversely proportional to the cubic root of the ossicular mass. This prediction is in reasonable agreement with published audiogram data. We then present a three-parameter model of the middle ear where some obvious deviations from perfect isometry are taken into account. The high frequency hearing limits of different species generally agree well with the predictions of this simple model. However, the hearing limits of small rodents clearly deviate from the model calculation. We interpret this observation as indicating that the hearing limit towards very high frequencies may be set by cochlear transduction mechanisms. Further we discuss the exceptional high frequency hearing of the cat and the amphibious hearing of seals.

Nummela, S., 1995. Scaling of the mammalian middle ear. Hear Res 85, 18-30.
Abstract: This study considers the general question how animal size limits the size and information receiving capacity of sense organs. To clarify this in the case of the mammalian middle ear, I studied 63 mammalian species, ranging from a small bat to the Indian elephant. I determined the skull mass and the masses of the ossicles malleus, incus and stapes (M, I and S), and measured the tympanic membrane area, A1. The ossicular mass (in mg) is generally negatively allometric to skull mass (in g), the regression equation for the whole material (excluding true seals) being y = 1.373 x(0.513). However, for very small mammals the allometry approaches isometry. Within a group of large mammals no distinct allometry can be discerned. The true seals (Phocidae) are exceptional by having massive ossicles. The size relations within the middle ear are generally rather constant. However, the I/M relation is slightly positively allometric, y = 0.554 x(1.162). Two particularly isometric relations were found; the S/(M + I) relation for the ossicles characterized by the regression equation y = 0.054 x(0.993), and the relation between a two-dimensional measure of the ossicles and the tympanic membrane ares, (M + I)2/3 /A1. As in isometric ears the sound energy collected by the tympanic membrane is linearly related to its area, the latter isometry suggests that, regardless of animal size, a given ossicular cross-sectional area is exposed to a similar sound-induced stress. Possible morphological middle ear adaptations to particular acoustic environments are discussed.

Rasmussen, L.E.L., 1995. Evidence for long-term chemical memory in elephants. Chemical Senses 20, 762.
Abstract: Asian elephants may have a mechanism to avoid close inbreeding that is mediated through the chemical senses. During the year-long postnatal, nursing period and for a number of years afterwards, young elephants live in intimate association with their mothers and closely related females. Although receptor cells were not detected in the vomeronasal organ (VNO) of newborn elephants (Rasmussen et al., 1993. Chemical Senses 18:618), the VNO is presumed to mature within 4-17 weeks postnatally to coincide with the first recognizable flehmen responses by young elephants. Over the past decade we have recorded the chemosensory-oriented behaviors of five calves during their first year. These young elephant, living within their natal group, were observed to flehmen to the urine from their mother twice as frequently as to urine from other females, both relatives and non-relatives. In the wild, by gradual exclusion, and in captivity, by actual removal for management reasons, prepubertal males are physically separated from their natal group. As adults, these males, prior to mating, cue into pheromones in preovulatory urine with a high frequency of flehmen responses (Rasmussen et al., 1993. J. Chem. Ecol. 19:2115). However, individual cues in maternal urine may override estrous cues. Adult males did not respond with high frequency to estrous urine from their mothers. However, chemical extracts of estrous maternal urine elicited high responses by male offspring, suggesting that the individual identity cues have been removed. We hypothesized that young elephant calves imprint on maternal urine and that they retain a chemical memory of this maternal urine over years. We have tested elephants who have been physically distant from their mothers for two to twenty-seven years. These offspring demonstrated a significantly higher response to maternal urine, whether recently collected or stored frozen since the test elephant's postnatal period, than to all other controls including long-time-ago-familiar, unrelated or non-maternally related urine, recently familiar urine, and non-maternal, lactating urine. Our data suggest chemical memory, via maternal urine, may allow filial-to-maternal recognition over time and space separations.

Kuttin, E.S., Muller, J., 1994. The fungal flora of zoo animals' ears. Mycoses 37, 59-60.
Abstract: The mycotic flora of the ears of zoo animals was investigated in a large zoological garden in Duisburg, Germany. Malassezia pachydermatis was isolated from the following animals: giant ant-eater (Myrmecophaga tridactyla), brown bear (Ursus arctos), common wombat (Vombatus ursinus), Eurasian badger (Meles meles), Indian elephant (Elephas maximus bengalensis), Mangaliza pig (Potamochoerus sus scrofa domestica) and white rhinoceros (Ceratotherium simum). Aspergillus fumigatus, A. niger, Candida guilliermondii, Geotrichum candidum, Trichosporon cutaneum [T. beigelii], Rhizopus microsporus, R. oryzae and Penicillium sp. were also isolated.

Rasmussen, L.E.L., Perrin, T.E., Rasmussen, R.A., Gunawardena, R., 1994. Isolation of potential musth-alerting signals from temporal gland secretions of male Asian elephants (Elephas maximus). Chemical Senses 19, 540.

Rasmussen, L.E.L., 1994. Sensory and Communication Systems. Medical Management of the Elephant. Indira Press, West Bloomfield, Michigan, USAI, pp. 207-217.

Bengis, R., 1993. Care of the African elephant Loxodonta africana in captivity. The capture and care manual : capture, care, accommodation and transportation of wild African animals. Pretoria : Wildlife Decision Support Services : South African Veterinary  Foundation, Pretoria, pp. 506-511.

Coetzee, E.M., Van-der-Bank, F.H., Critser, J.K., 1993. Allozyme variation in a wild African elephant (Loxodonta africana) population from the Kruger National Park, South Africa. Comparative Biochemistry and Physiology B-Comparative-Biochemistry 106, 109-114.
Abstract: 1. Blood, liver, heart, testis, skin, eye, muscle and kidney samples were obtained from elephants (Loxodonta africana) in the Kruger National Park during a culling programme in April 1992. 2. Gene products of 25 protein coding loci in L. africana were examined by horizontal starch-gel electrophoresis. 3. Eighteen protein coding loci (72%) displayed monomorphic gel banding patterns whereas only seven (28%) displayed polymorphic gel banding patterns. 4. Average heterozygosity values for adults, youngsters and the total population are respectively 0.058, 0.024 and 0.047. 5. Relative gene diversities within and between populations are 84% and 16% respectively. 6. Two population simulation programmes were utilized to predict the duration of the current variability present in this species, based on current genetic variation and gene transfer from one generation to the next.

Ebedes, H., 1993. The use of long-acting tranquilizers in captive wild animals. The capture and care manual : capture, care, accommodation and transportation of wild African animals. Pretoria : Wildlife Decision Support Services : South African Veterinary  Foundation, Pretoria.

Kern, T.J., Murphy, C.J., Howland, H.C. Physiological optics and ocular anatomy of the Asian elephant (Elephas maximus). Proceedings of the American Association of Zoo Veterinarians.  355. 1993.
Ref Type: Conference Proceeding

Lloyd, M., Goddard, M., Zeinowicz, R., Harper, J.S., III, 1993. One approach to the removal of an aural rhabdomyoma in a 7 year old african elephant. Proceedings American Association of Zoo Veterinarians 115-119.

Rasmussen, L.E.L., Johnson, E.W., Jafek, B.W. Preliminary observations on the morphology of the vomeronasal organ of a newborn Asian elephant. Chemical Senses 18, 618. 1993.
Ref Type: Abstract
Abstract: Abstract.  Full-text.  Adult Asian elephants have an apparently typical mammalian vomeronasal organ (VNO). Presumably, flehmen responses aid in the presentation of bioactive molecules to vomeronasal neuroreceptors.  Young Asian elephants do not exhibit flehmen responses until 6-17 weeks after birth. Histological studies of VNO in newborn elephants have not been available.  Recently, at the light microscopic level, we have observed a structure that in gross appearance is similar to the VNO of other mammals; there is a lumen surrounded by a convex and a concave epithelial border, those borders join at both ends.  Based on previous studies, we presume that the concave border would be the neuroepithelium with the receptor cells. The epithelia of both surfaces are pseudostratified.  Within these epithelia are cells with different nuclear morphologies. Some of the nuclei are euchromatic and oval.  Other appear heterochromatic.  Round basal cells are also apparent.  At the surfaces of the epithelia some ciliated cells can be seen.  To our knowledge, ciliated cells have been identified in the VNO neuroepithelium of only one other mammalian species.  To further document the cell types found in the newborn elephant VNO and to attempt to identify receptor cells, we will do electron microscopy on representative regions.

Rasmussen, L.E.L., Lee, T.D., Daves, G.D., Schmidt, M.J., 1993. Identification of indolo [2,1-b] quinazoline-6,12-dione in the pre-ovulatory, estrous urine of Elephas maximus. Journal of Chemical Ecology 19, 2115-2128.

Rasmussen, L.E.L., Lee, T.D., Daves, G.D.Jr., Schmidt, M.J., 1993. Female-to-male sex pheromones of low volatility in the Asian elephant, Elephas maximus. Journal of Chemical Ecology 19, 2115-2128.
Abstract: In their natural ecosystems, the sexes of Asian elephant, Elephas maximus, live separately.  For several weeks prior to ovulation, the urine and cervical mucus of female Asian elephants contain extractable chemical agents of low volatility that elicit a high frequency of flehmen responses from bull elephants as an integral part of mating.  Subsequent to flehmen responses, male sexual arousal occurs and, if the female is available, mating results.  During the course of our project to determine the agent(s) and describe the responses associated with female to male sexual communication, we have identified an unusual compound.  This compound, apparently the sole component of the active fraction, was identified by mass, proton nuclear magnetic resonance, ultraviolet/visible, and infrared spectrometries as indolo-[2,1-b]quinazoline-6,12-dione (tryptanthrine).  Exhaustive and repetitive bioassays established that pure authentic (synthetic) typtanthrine was not the compound responsible for the bioresponse.   Rather a coeluting minor component, of low volatility, elicited the male bioresponse.

Rasmussen, L.E.L., Schmidt, M.J. Filial-maternal chemorecognition in Asian elephant. American Society of Mammmalogists . 1993.
Ref Type: Abstract

Shyan, M.R., Dale, R.H.I., Collins, D., Olson, D., Critser, J.K., Noiles, E.E. Preliminary findings on vocal harmony and behavioral relationship in captive African elephants. Proc. Ann. Elephant Workshop. Proceedings of the Annual Elephant Workshop . 1993.
Ref Type: Conference Proceeding

Murphy, C.J., Kern, T.J., Howland, H.C., 1992. Refractive state, corneal curvature, accommodative range and ocular anatomy of the Asian elephant (Elephas maximus). Vision Res 32, 2013-2021.
Abstract: The resting refractive state of six mature, female, Asian elephants (Elephas maximus) was determined using streak retinoscopy and neutralizing video retinoscopy. The amplitude of accommodation was also measured by neutralizing video retinoscopy of two animals and the corneal curvatures of three animals was measured by photokeratoscopy. The net spherical refraction was found to be +0.23 D. No difference was observed between cyclopleged and non-cyclopleged eyes (data from three animals), nor was there any difference between right and left eyes. Nine of the twelve eyes refracted had > or = 0.5 D astigmatism. The mean corneal power, as measured by photokeratometry was 21.3 D (SD = 1.8 D). There was a tendency towards with-the-rule corneal astigmatism in our sample (mean value: 1.2 D), though it did not reach statistical significance (P = 0.06). Two elephants were examined using neutralizing video photoretinoscopy. They were able to accommodate through 3 D. Three fixed eyes from three different elephants were obtained for gross and microscopic examination. The mean axial length of the eye was 38.75 mm and the lens had an axial diameter of approx. 10 mm. The posterior sclera was thick (8.0-8.5 mm). Histologically, the cornea was comprised of five distinct layers. A thin, meridionally oriented smooth ciliary muscle was identified. Individual muscle fibers were also observed associated with the posterior trabeculae of the uveal meshwork.

Payne, K.B., Langbauer, W.R., Jr., 1992. Elephant communication. In: Shoshani, J. (Ed.), Elephants: Majestic Creatures of the Wild. Rodale Press, Emmaus, PA. USA, pp. 116-123.

Phillips, P.K., Heath, J.E., 1992. Heat exchange by the pinnae of the African elephant (Loxodonta africana). Comparative Biochemistry and Physiology [A] 101, 693-699.
Abstract: 1. Surface temperatures of the pinnae of four female African elephants were measured at ambient temperatures between 14 and 32 degrees C using infrared thermography. Instantaneous heat losses calculated using those values ranged from 10.67 to 76.2 W under the observed conditions. 2. Using a value of 17 kcal/kg/day, those heat losses account for 0.65-4.64% of the animals' standard metabolic rates, considering one side of one ear only. 3. A model of heat flow across a flat vertical plate was constructed and compared to the actual values. Up to 100% of an African elephant's heat loss needs can be met by movement of its pinnae and by vasodilation. 4. Thermography indicates that the temperature distribution pattern across the pinna changes with ambient temperature and that areas of specialized motor control exist

Rasmussen, B., Davies, G.D., Lee, T.D. An unusual compound and further characterization of a preovulatory pheromone of Asian elephants, Elephas maximus. Chemical Senses 17, 687. 1992.
Ref Type: Abstract
Abstract: Abstract.  Full text.  A compound isolated from pre-ovulatory urine of Asian elephants as apparently a single entity (as assessed by a single band on TLC, a single peak by HPLC and a single dominant mass by field desorption mass spectrometry [FDMS]), was consistently active during bioassay and exhibited a reproducible dose-response curve.  Once pure (apparently), this compound was rapidly identified using a combination of spectral and mass spectral techniques. The principal component of the active fraction exhibited a molecular ion (m/z) at 248.  An exact mass measurement on the molecular ion was obtained by electron ionization (EI) mass spectrometry (MS) analysis.  From the mass of 248.056, the composition C15H8N2O2 was established. The isotope distribution of the molecular ion calculated from this composition was consistent with that observed in the mass spectrum.  UV spectral data indicated an extended, complex chromophore, probably a nitrogen heterocyclic.  Fragmentation information by collision-activated, EIMS demonstrated ions at 220 and 192.  The fragment ions in the EI spectrum (m/z 220 and 192) were consistent with the sequential loss of carbonyl groups; Fourier transform infrared (FTIR) spectra also indicated carbonyls.  Definitive NMR data indicated eight aromatic hydrogens, assigned on the basis of their coupling characteristics observed in the 2-D spectrum that were individually assigned to two different benzene rings.  All of these spectral data and comparison with an authentic sample established unambiguously the structure as indolol[2,1-b]-quinazoline-6,12-dione (tryptanthrine). Subsequent bioassays of the synthetic, authentic compound exhibited an initial high, novel substance response, followed by a sustained low-level response which gradually diminished to zero during a 6th month test period.  Several hundred bioassays of wide ranges of concentrations and conditions were conducted such that we are reasonably sure that tryptanthrine is not the active pheromone.  Re-evaluation of the active elephant preparation by HPLC and UV spectrometry demonstrated an earlier eluting, UV distinctive peak that, when isolated and bioassayed by itself, was active.  Preliminary data on this compound are reported.  Supported by NIH grant HD  19219-06.

Wiesner, H., 1992. Occurrence of Arcus scleralis in elephants. Zoologische Garten 62, 287-293.

Wolfer, J., Rich, P., 1992. Persistent corneal erosion in an Asian elephant. Canadian Veterinary Journal 33, 337-339.

Chakraborty, A., Islam, S., Gogoi, A.R., Chaudhury, B., 1991. A note on clinical examination of elephants in Manas Tiger Project and Kaziranga National Park in Assam. Zoos' Print Journal November.
Abstract:
The diseases of elephants have been recorded by Steel (1885) and Evans (1910) and till then many works have done on elephants. Compared to the extent of work done in other states of our country, very little investigation seems to have been done in Assam. The present communication relates the report of investigation carried out in the domesticated elephants of Manas Tiger Project and Kaziranga National Park in Assam.

Kuruwita, V.Y., Abeysinghe, A.B. Surgical correction of blindness due to mature cataract in a domesticated Asian elephant. International Seminar on Veterinary Medicine in Wild & Captive Animals, Bangalore, India, November 8 to 10, 1991.  23. 1991.
Ref Type: Conference Proceeding
Abstract: Full text: Cataract is a common condition affecting the vision of about 6-8% domesticated elephants in Sri Lanka. A thirty five year old, Asian elephant (Elephas maximus maximus) was presented to the veterinary teaching hospital with a complaint of impaired vision in both eyes. At initial examination it was revealed that the animal was blind in the right eye by birth and subsequently developed a cataract in the other eye. Native treatment was sought and despite continuous treatment the vision deteriorated over a period of two years and the animal became totally blind and helpless, depending totally on the mahout for ambulation. The affected eye was examined and was diagnosed as a mature cataract with the possibility of partial anterior displacement of the lens. Subsequent to complete clinical evaluation of the patient a total lendectomy was performed on the left eye. This paper describes the anesthetic methods adopted, the surgical approach the post operative care and the prognosis of the unique operation.

Langbauer, W.R., Jr., Payne, K.B., Charif, R., Rapaport, L., Osborn, F., 1991. African elephants  respond to distant playback of low-frequency conspecific calls. J Exp Biol 157, 35-46.

Rasmussen, L.E.L., Lee, T.D. Purification and initial characterization of a pre-ovulatory pheromone from female Asian elephants (Elephas maximus). Chemical Senses 16, 569. 1991.
Ref Type: Abstract
Abstract: Abstract.  Full text.  Urine from female Asian elephants in the pre-ovulatory phase of the ovarian cycle elicits a high frequency of flehmen responses from Asian bulls in a non-habituating manner.  These flehmen responses are an integral part of the mating sequence and suggest the presence of a sex pheromone.  Extraction and partial purification of components with retention of high biological activity was accomplished several years ago [Rasmussen et al. (1982) Science, 217, 159-162].  Subsequently, standard isolation techniques and molecular weight characterization by conventional mass spectrometric methods proved ineffective.  The pheromone was not identifiable by gas chromatography/ mass spectrometry (both electron impact and chemical ionization) nor by solid probe inlet electron impact mass spectrometry.  The pheromone appeared to be a compound of low volatility, of low molecular weight (200-500) and to be thermally labile.  It was not a peptide. The purification was hampered by close association of high concentrations of inactive components, often aromatics, which possessed similar chromatographic properties.  Purified by an empirically determined series of low pressure and high performance liquid chromatography fractionation sequences, guided at each step and in each preparation by high frequency flehmen responses from Asian bull elephants, the active sex pheromone is apparently a single entity.  Recent developments in field desorption mass spectrometric techniques allow molecular weight determinations on several micrograms of thermally labile substances; by this technique the protonated molecular weight was determined to be 249 and a tentative molecular weight of 248 is assigned.  Further information is presented on the physical and chemical properties of the elephant pheromone including its ultraviolet absorption maximum and it nuclear magnetic resonance spectrum.  Supported by NIH grant HD-19219-06.

Ratnasooriya, W.D., Fernando, S.B.U., Manatunga, A.N.V.R., 1991. Presence of an arcus senilis-like structure in the eyes of Sri Lankan elephants (Elephas maximus maximus). Med. Sci. Res. 19, 715-716.

Fischer, M.S., 1990. The unique ear of elephants and manatees (Mammalia): A phylogenetic paradox. C. R. Acad. Sci. Ser. III Sci. Vie 311, 157-162.

Rasmussen, D.T., Gagnon, M., Simons, E.L., 1990. Taxeopody in the carpus and tarsus of Oligocene Pliohyracidae (Mammalia:Hyracoidea) and the phyletic position of hyraxes. Proc Natl Acad Sci U S A 87, 4688-4691.
Abstract: Recent hyracoids and elephants share a taxeopode arrangement of tarsal and carpal bones, a condition in which bones are aligned with minimal interlocking between adjacent elements. Taxeopody has often been interpreted as a synapomorphy reflecting a close phyletic link between Hyracoidea and Proboscidea, but recently it has been suggested [Fischer, M. S. (1986) Cour. Forschungsinst. Senckenberg 84, 1-132] that hyracoid taxeopody is an independent acquisition resulting from selection favoring increased midcarpal and midtarsal rotation and that Hyracoidea is actually allied with Perissodactyla. As a test of this hypothesis, isolated carpal and tarsal bones of primitive Oligocene hyracoids from the Fayum, Egypt, have been examined to determine whether these indicate a taxeopode or diplarthral carpus and tarsus. Four complete astragali from the Fayum, representing at least three taxa, show a single, slightly convex articular surface on the head for articulation with the navicular and lack a facet for the cuboid. Two complete magna representing two species have a single proximal facet for articulation with the lunar, and they lack a facet for the scaphoid. Thus, both the carpus and tarsus of Fayum hyracoids are taxeopode. Taxeopody in hyracoids cannot be attributed to selection for carpal and tarsal rotation in climbers because the Oligocene, Miocene, and Recent species show great diversity in body size and probably locomotor specializations, despite relative uniformity of structure in the carpus and tarsus. The shared taxeopody of hyracoids and proboscideans, along with other osteological characters and similarities in hemoglobin, eye lens proteins, and other molecules, all suggest that Hyracoidea belongs within Paenungulata.

Rasmussen, L.E.L., Hultgren, B., 1990. Gross and microscopic anatomy of the vomeronasal organ in the Asian elephant. In: McDonald, D.W., Muller-Schwarze, D., Natynczuk, S.E. (Eds.), Chemical signals in vertebrates 5. Oxford University Press, New York, pp. 154-161.

Rasmussen, L.E.L., Hess, D.L., Hall-Martin, A. Chemical profiles of temporal gland secretions from captive Asian bull elephants during musth and from African bull elephants living in wild but crowded conditions. Chemical Senses 15, 628. 1990.
Ref Type: Abstract
Abstract: Full-text: This study compares the volatile components of the temporal gland secretions of captive Asian bull elephants in musth and a distinctive group of wild African bull elephants, confined to a national park.  The captive Asian population has been well studied (Rasmussen et al., 1984; Rasmussen, 1988). Serum testosterone was elevated at specific times; aggressive behaviors occurred concomitantly with temporal gland secretions, although aggression and elevated serum testosterone were not always related.  Selected volatiles among the 23 compounds identified demonstrated concentration changes during the progression of musth, at times simultaneously with alterations in testosterone levels (Rasmussen et al., in press).  The African bull elephants have been monitored, behaviorally and physiologically, by radiocontrolled tracking and monthly sampling during the past 5 years.  Aggressive behaviors similar to those of Asian bull elephants have been documented; serum and temporal gland testosterone were elevated concomitantly in a cyclical fashion similar to musth in Asian elephants.  Chemical characterization of the volatiles of the temporal gland secretions from these bulls revealed several similarities to the compounds described in Asian bulls, including several compounds not previously described in African temporal gland secretions.  It is suggested that these chemicals, or other, more ephemeral compounds, may chemically inform other bulls and cows of the musth-like state of these bulls.

Rasmussen, L.E.L., Hess, D.L., Haight, J.D., 1990. Chemical analysis of temporal gland secretions collected from an Asian bull elephant during a four-month musth episode. Journal of Chemical Ecology 16, 2167-2181.
Abstract: The temporal glands, modified facial apocrine sweat glands unique to elephants, release collectable secretions during an unusual physiological state termed "musth" in the Asian bull elephant (Elephas maximus).  Recently we began the characterization of the chemical components of musth, especially in the temporal gland secretions (TGS), and the examination of the role of such secretions as agents for chemical communication among elephants.  The presents study focuses on possible correlations between testosterone levels and the serum and temporal gland secretions.  We were especially interested in possible qualitative and/or quantitative changes in volatile compounds as the testosterone levels varied during a discrete musth period.  Ouantitative changes in TGS and serum testosterone were determined by radioimmunoassay.  Qualitative and semiquantitative changes occurring in volatile composition were studied by high-resolution gas chromatography (fused silica capillary column, on column injection).  Compound identification was by nuclear magnetic resonance, gas chromatography-mass spectrometr, and gas chromatography internal standards. Twenty-three major compounds and a number of minor components were identified.  Androgen concentrations were correlated with TGS-specific volatiles including benzoic acid, 2-nonanone, 5-nonanol, tetradecanoic acid and decanoic acid.  The latter two compounds and (E)-farnesol, a major component of African TGS, demonstrated an inverse relationship to T levels.

Rasmussen, L.E.L., Munger, B. Micro-anatomy of the trunk tip of Elephas maximus. Chemical Senses 15, 629. 1990.
Ref Type: Abstract
Abstract: Full-text:  This study documents the characteristics of the sensory innervation and cutaneous receptors in the dermal and epidermal skin of the extreme trunk tip (finger) and adjacent skin of the Asian elephant Elephas maximus by light microscopy.  During the flehmen response the elephant moistens the trunk tip with liquids of interest and apparently uses this tip for transport of such substances to the mucous-filled openings of the incisive ducts, which lead to the vomeronasal organ.  We expected to find this region of the trunk tip richly innervated, perhaps with specialized nerve endings, especially in the epidermis.  Unexpectedly, our light microscopic examinations demonstrated three distinctive features.  First, a uniquely high density of free nerve endings are apparent in the superficial layers of the trunk tip skin.  Second, in the skin closely associated with the trunk tip unusual tiny short vibrissal hairs surrounded by hundreds of axons were interspersed with more conventional vibrissal hairs.  Third, unique complex branched encapsulated corpuscles were abundant in the superficial layer of the dermis in the area of the tip and in the closely associated skin. This study provides basic histological information about the trunk tip region as the initial part of our investigation of the innervation, cutaneous sensory receptors, especially possible chemosensory receptors of the trunk and its orifices.

Elephant.  1989. Washington, D.C.], National Geographic special; Distributed by Vestron Video; DNAL Videocassette-no.1154.
Ref Type: Online Source
Abstract: The video is an in-depth look at the elephant and its precarious future.  Covers Asian and African elephants, their behavior, their methods of communication, and their society.

Langbauer, W.R., Jr., Payne, K.B., Charif, R.A., Thomas, E.M., 1989. Reponses of captive African elephants to playback of low-frequency calls. Canadian Journal of Zoology 67, 2604-2607.
Abstract:  We conducted a series of playback trials with captive African elephant to identify behaviors that might indicate perception of calls by conspecifics.  Our findings were as follows. (i) The elephants responded clearly to playbacks of prerecorded low-freqency elephant calls.  Responses included, in rough sequence, lifting and stiffening of ears, vocalization, walking or running towards the concealed speaker, clustering in a tight group, and remaining motionless ("freezing"), with occassional scanning movements of the head.  The occurrence of each of these behaviors increased substantially immediately after the playbacks.  (ii) Elephants responded to full-bandwidth playbacks and to playbacks of calls in which most of the above 25 Hz was filtered out, simulating the effect of frequency-dependent attenuation over distance.  (iii) Elephants did not respond to pure-tone control stimulus similar in frequency and intensity to the filtered elephant calls.  Thus, the observed responses to the elephant calls were not merely responses to an unexpected stimulus, but probably indicate recognition of a biologically meaningful signal.

Payne, K., 1989. Elephant talk. National Geographic 176, 264-277.

Poole, J.H., Moss, C.J. Elephant mate searching: group dynamics and vocal and olfactory communication. Symposia of the Zoological Society of London.  111-125. 1989.
Ref Type: Conference Proceeding

Stone, J., Halasz, P., 1989. Topography of the retina in the elephant Loxodonta africana. Brain,Behavior and Evolution 34, 84-95.
Abstract: The distribution of neurones in the ganglion cell layer of the retina of an African elephant is described. The eye was obtained post-mortem from an infant animal, which died of an unknown disease. It is assumed that most of the neurones observed in the ganglion cell layer are ganglion cells. Ganglion cells concentrate along a horizontal axis extending across the retina inferior to the optic disc, as in the visual streak described in the retina of many mammals. They also concentrate in the upper temporal retina, in a pattern distinctive to elephants. We suggest that this latter concentration has evolved to monitor the animal's trunk. Features of the eye, including its size, orientation and fundal pigmentation, are also described.

Banziger, H., 1988. The heaviest tear drinkers: ecology and systematics of new and unusual notodontid moths. Natural History Bulletin of the Siam Society 36, 17-53.
Abstract: Seven moths are described: Tarsolepis elephantorum sp. nov., Poncetia bovoculosugens sp. nov., P. doisuthepica sp. nov., P. huaykaeoensis sp. nov., all from Doi Suthep, Chiang Mai Province, Thailand; T. equidarum sp. nov., P. siamica sp. nov. from elsewhere in northern Thailand; and P. bhutanica sp. nov. from Bhutan and Meghalaya, India. The subspecies P. albistriga sphingoides and P. a. kanshireiensis are new synonyms of P. albistriga albistriga; P. fuscipennis comb. nov. is a new combination transferred from Ramesa. Nocturnal field research during 17 years in Thailand, western Malaysia and other countries has shown T. elephantorum, T. equidarum, T. remicauda, P. albistriga, P. bovoculosugens, P. huaykaeoensis and Pydnella rosacea to be lachryphagous: male moths suck lachrymal secretions from eyes, and/or other fluids from the body, of Asian elephant (Elephas maximus), Malayan tapir (Tapirus indicus), black rhinoceros (Diceros bicornis), 4 deer (Hyelaphus porcinus [Cervus porcinus], C. unicolor, C. dama and C. elaphus) and 2 antelope species (Boselaphus tragocamelus and Antilope cervicapra), and 5 species of domestic ungulates (horses, mules, donkeys, buffaloes and cattle). P. rosacea drank tears from the author's eye 8 times, Tarsolepis elephantorum 3 times, and many more unsuccessful attacks were experienced. This is the first report of Notodontidae feeding on human tears. Details are given of the moths' distribution, habitats, types of food, feeding behaviour, host preferences, host reactions, and seasonal abundance. Reasons for the sucking of tears by, and its restriction to, nocturnal Lepidoptera are offered.

Poole, J.H., Payne, K., Langbauer, W.R., Moss, C.J., 1988. The social context of some very low frequency calls of African elephants. Behavioral Ecology and Sociobiology 22, 385-392.

Rasmussen, L.E.L., 1988. Chemosensory responses in two species of elephants to constituents of temporal gland secretion and musth urine. Journal of Chemical Ecology 14, 1687-1711.
Abstract: This report discusses three areas of investigation: (1) The chemical components in the temporal gland secretion (TGS) of Asian (Elephas maximus) and African (Loxodonta africana) elephants were characterized by radioimmunoassay (RIA) for testosterone (T) and dihydrotestosterone(DHT) levels and by on-column capillary column gas chromatographic analysis of volatiles.  An inverse relationship between TGS testosterone levels and (E)-farnesol levels was observed. (2) African elephants responded preferentially toward a particular constituent of African elephant (TGS). (3) Urine from Asian bull elephants in musth was partially fractionated by high-performance liquid chromatography.  Specific chromatographic regions elicited dramatic avoidance responses from female African elephants.  These results support the suggestion that the TGS plays multiple chemocommunicative roles.

 1986. Elephant calls humans can't hear. Science News 129, 122.

 1986. Elephant talk. Science Digest 94, 15.

Payne, K.B., Langbauer, W.R., Thomas, E.M., 1986. Infrasonic calls of the Asian elephant (Elephas maximus). Behavioral Ecology and Sociobiology 18, 297-301.
Abstract: Calls at frequencies below the range of human hearing were recorded from two groups of captive Asian elephants (Elephas maximus).  Most of the calls ranged in frequency from 14 to 24 Hz, with durations of 10-15 s (Fig. 1).  With the nearest elephant 5 m from the microphone, sound pressure levels were 85 to 90 dB (re 20 microPa).  These calls occurred in a variety of circumstances.  Elephants are the first terrestrial mammals reported to produce infrasound.  These calls might be important in the coordination of behavior in thick vegetation or among separated groups of elephants.

Rasmussen, L.E., Schmidt, M.J., Daves, G.D., 1986. Chemical communication among Asian elephants. In: Duvall, D., Silverstein, M., Muller-Schwarze, D. (Eds.), Chemical Signals in Vertebrates: Evolutionary, Ecological, and Comparative Aspects. Plenum Press, pp. 627-646.

Wemmer, C., Mishra, H., Dinerstein, E., 1985. Unusual use of the trunk for sound production in a captive Asian elephant: a second case. Journal of the Bombay Natural History Society 82, 187.

Domrow, R., Ladds, P.W., 1984. A new ear mite from the Indian elephant (Acari:Anoetidae) [Loxanoetus lenae]. J. Nat. Hist 18, 759-764.

Rasmussen, L.E., Buss, I.O., Hess, D.L., Schmidt, M.J., 1984. Testosterone and dihydrotestosterone concentrations in elephant serum and temporal gland secretions. Biology of Reproduction 30, 352-362.
Abstract: Serum and termporal gland secretions (TGS) were obtained from mature wild African (Loxodonta africana) and captive Asian (Elephas maximus).  Samples were obtained from five cows and eight bulls culled for management purposes in Kruger National Park, South Africa, and from four females and two males residing at the Washington Park Zoo, Portland, Oregon.  Our purpose was to describe the levels of androgens, testosterone, and dihydrotestosterone, and to correlate these observations with sex, species, and behavioral status.  Male-female differences in serum T were pronounced in the Asian species, whereas male and female concentrations overlapped in the African elephant serum. Serum T concentrations in African females were > than in Asian females.  Serum DHT reflected T levels, except that the striking elevation of testosterone in Asian bulls during musth was not paralleled by = increases in DHT.  A species difference observed among males was higher serum T levels in nonmusth Asian bulls (1.84-5.35ng/ml) compared to levels in African bulls (0.38-0.68ng/ml), except for one dominant African bull (6.64ng/ml).  This single African value was still considerably lower than the serum T values of the Asian males during musth. These musth values were the highest serum androgen concentrations: T was between 19 and 40ng/ml (average 26.1 ng/ml).  The TSG values of T and DHT were much higher than serum levels except in the Asian female.  T/DHT ratios in TGS were more similar than in serum.  One dominant African bull had a T TGS value of 78ng/ml, which was much higher than the rest of the African males or females, but considerably lower than an Asian bull in musth (547ng/ml).  It seems apparent that a change in androgen status as reflected in serum and TGS levels of T and DHT precedes or is concomitant with overt alteration in behavior in the Asian male.  The temporal gland appears to actively concentrate androgens in both African males and females, but in the Asian male the gland secretes only during musth when the greatest concentration of both T and DHT were observed.  The apparent difference in the degree of temporal gland secretory activity between the 2 species suggests a more specific communicative function within the Asian male.

Berg, J.K., 1983. Vocalizations and associated behaviors of the African elephant (Loxodonta africana) in captivity. Zeitschrift fur Tierpsychologie 63, 63-78.
Abstract: This analysis presents the physical characteristics of the vocalizations of the African elephant and describes the associated behavioral contexts of the elephant's communicative system.  One male and 8 female African elephants were systematically observed in a relatively large captive environment.  Their repertoire of sounds constitutes 10 distinct vocalizations which are emitted during 11 behavioral categories.  Although all but one of the sounds is emitted in more than one context, many of the sounds are more characteristic of a specific behavior than others.  An interesting finding is that the fundamental frequency of the emitted sound is significantly correlated to the level of excitement of the individual.  In general, sounds with a low fundamental frequency are emitted within the animals are in a low level of excitement and are important in those behaviors which promote group cohesion and the orderly interactions of individuals.  In contrast, the higher fundamental frequency sounds predominate when the animals are in a high level of excitement and are emitted most often during aggressive type behaviors.  The elephants' vocalizations are associated behaviors in captivity are discussed in comparison to those of their free-living relatives and those of other animals showing similarities across some of the sounds and behaviors.

Heffner, R., Heffner, H., Stichman, N., 1982. Role of the elephant pinna in sound localization. Animal Behavior 30(2), 628-630.

Heffner, R.S., Heffner, H.E., 1982. Hearing in the elephant (Elephas maximus):  Absolute sensitivity, frequency discrimination, and sound localization. Journal of Comparative and Physiological Psychology 96, 926-944.
Abstract: A young Indian elephant was tested to determine its absolute sensitivity, frequency-discrimination thresholds, and sound-localization thresholds.  The elephant was found to have an audibility curve similar to that of other mammals but one that is more sensitive to low frequencies and less sensitive to high frequencies than any other mammalian audiogram including human's.  The elephant's sensitivity to frequency differences at low frequencies was found to equal that of humans.  Finally, the elephant was found to be very accurate at localizing sounds in the azimuthal plane, with thresholds around 1 degree for broadband noise.  The elephant's ability to localize pure tones suggested that it could use both binaural time- and intensity-difference cues to localize sound.

Rasmussen, L.E., Schmidt, M.J., Henneous, R., Groves, D., Daves, G.D.Jr., 1982. Asian bull elephants: flehmen-like responses to extractable components in female elephant estrous urine. Science 217, 159-162.
Abstract: Flehmen-like responses (urine tests) are one of the characteristic behavioral reactions of male Asian elephants (Elephas maximus) to cow elephants in estrus.  Components of the urine of estrous cow elephants were extracted with organic solvents and partially purified by chromatography and shown to evoke Flehmen-like responses when they were presented to adult bulls.

Wheeler, J.W., Rasmussen, L.E., Ayorinde, F., Buss, I.O., Smuts, G.L., 1982. Chemical constituents of temporal gland secretion of the African elephant, Loxodonta africana. Journal of Chemical Ecology 8, 821-835.
Abstract: Temporal gland secretion (TGS), obtained from 15 different mature African elephants in Kruger National Park was analyzed for volatile constituents.  Only five volatile components were present. p-Cresol was present in all samples, but phenol was found as an appreciable component of only one sample and as trace amounts in six others.  Three sesquiterpenes were identified, the latter two being new natural products: E-farnesol, farnesol hydrate (3,7,11-trimethyl-2,10-dodecadien-1,7 diol), and farnesol dihydrate (3,7,11-trimethyl-2-dodecen-1,7,11-triol).  These sesquiterpenes represent the first isolated from mammals.  Ten samples of TGS, serum, and saliva were assayed for cholesterol, urea, and proteins including several enzymes.

Altmann, D., Krebs, W., 1981. Combined Vetalar-Combelen anesthesia of elephant for surgical removal of foreign body from eye. Erkrankungen der Zootiere 261-265.

Heffner, H., Heffner, R., 1981. Functional interaural distance and high-frequency hearing in the elephant. Journal of the Acoustical Society of America 70, 1794-1795.
Abstract: Auditory thresholds were determined for a 7-year-old Indian elephant. The animal cound hear only as high as 10.5 kHz (at an intensity of 60 dB SPL) and was unable to respond to frequencies above 12 kHz at intensities exceeding 90 dB.  The results indicate that the inverse relationship between functional interaural distance (that is, the distance between the two ears divided by the speed of sound) and high-frequency hearing limit is valid even for very large mammals.

Heffner, H., Heffner, R. Research into elephant hearing. AAZPA Reg.Conf.Proc.  23-29. 1980.
Ref Type: Conference Proceeding

Heffner, R., Heffner, H., 1980. Hearing in the elephant (Elephas maximus). Science 208, 518-520.
Abstract: Auditory thresholds were determined for a 7-year-old Indian elephant. The hearing range extended from 17 hertz to 10.5 kilohertz. The results indicate that the inverse relationship between functional interaural distance (that is, the distance between the two ears divided by the speed of sound) and high-frequency hearing limit is valid even for very large mammals.

Vendan, C., 1979. The trunk, hand of the elephant. Study of its prehensile and tactile termination. Ann. Chir. Plast. 24,  392-396.

Cmelik, S.H.W., Ley, H., 1978. Neutral lipids from the temporal gland of the African elephant (Loxodonta africana). Lipids 13, 195-198.

Hass, G., 1978. Behavioural disorders in a female Indian elephant (Elephas maximus bengalensis) with bony structures on the intermediofacial and statoacoustic nerves. Zoologische Garten 48(4,S.), 297-298.

De Jong, W.W., Nuy-Terwindt, E.C., Versteeg, M., 1977. Primary structures of alpha crystallin A chains of elephant, whale, hyrax and rhinoceros. Biochim. Biophys. Acta 491, 573-580.
Abstract: As part of a study of the evolutionary development of the eye lens protein alpha-crystallin the 173 residue A chain of this protein has been studied in elephant, whale, hyrax and rhinoceros.  The primary sturctures were inferred mainly from amino acid compositions of peptides obtained by enzymatic digestions and CNBr cleavage.  The positions of substitutions, as compared to known bovine A chain, were confirmed by Edman degradation.  In accordance with the previously observed slow rate of evolution of the A chain only a small number of substitutions were found among these species.  Elephant and hyrax share a number of unique substitutions, strongly indicating a common ancestry of these two species within the mammalian class.

De Jong, W.W., Gleaves, J.T., Boulter, D., 1977. Evolutionary changes of alpha-crystallin and the phylogeny of mammalian orders. J Mol Evol 10, 123-135.
Abstract: The sequences of the A chains of the eye lens protein alpha-crystallin from seventeen mammalian species were compared. They showed a generally slow rate of evolution, but with marked variations in different lineages. Most substitutions have occurred in the C-terminal part of the chain, which probably forms part of the surface of the alpha-crystallin aggregate. The ancestral sequence method of Dayhoff revealed interesting indications about the phylogenetic relationships between the eleven mammalian orders that were represented by the investigated species. Most evident was the divergence of marsupial and placental orders. A notable resemblance between the hyrax and elephant sequences was observed, setting them apart from the ungulates, including whale. Primates, rodents, lagomorphs, insectivores and tupaiids seem to derive from a common stem group. These phylogenetic inferences are discussed in relation to current paleontological and taxonomical opinions, and compared to evidence from other protein sequence data.

Khan, M., 1977. The three senses of the Malayan elephant. Malayan Nature Journal 30, 31-34.

Buss, I.O., Estes, J.A., Rasmussen, L.E., Smuts, G.L., 1976. The role of stress and individual recognition in the function of the African elephant's temporal gland. Mammalia 40, 437-451.
Abstract: Biochemical measurements were made from a sample of temporal gland secretion from each of five wild African elephant bulls (23 to 38 years of age) collected in Kruger National Park, South Africa between November 1974 and April 1975.  Total protein content was high (26-57 mg/ml), acid phosphatase ranged between 1.9 and 6.3 mM/h/mgm protein, and lactic dehydrogenase levels were undetectable.  Total lipid content in the secretion averaged 80 mg% and ranged from 75 to 87 mg%.  Triglycerides were just detectable, varying from 2 to 8 mg%, and phospholipids ranged from 9 to 11 mg% (ave. 10 mg%).  Cholesterol content was surprisingly high, measuring 12, 19, 26, 36, and 70 mg% for five samples of secretion.    Field observations indicated that stress triggers liberation of temporal gland secretion.  Among 116 elephants collected in Uganda, secretory activity of their temporal glands was more frequent during dry (probably more stressful) than during wet seasons.  Among 62 elephants driven by helicopter to roadways for collection in Kruger National Park, 23 driven relatively far and fast were in prominent musth; most of those driven slower and shorter distances showed no evidence of musth.  The matriarchal leader of an elephant family near Lake Albert, Uganda developed very prominent temporal gland activity after an hour and 45 minutes of vigorously defending three of her family members.    Chemical individuality of cholesterol levels in temporal glands of five adult bulls suggests a pheromone-producing function which serves for individual recognition by the African elephant.  Direct observations of wild elephants also suggest that the temporal gland functions as a scent gland helping to recognize other members of the group or to find them.

Markowitz, H., Schmidt, M., Nadal, L., Squier, L., 1975. Do elephants ever forget? Journal of Applied Behavior Analysis 8, 333-335.
Abstract: The adult female elephants (Elephas maximus) were tested on a light-dark discrimination problem with an eight year intertrial interval.  The first subject took only six minutes to reach criterion and made only 2 errors, suggesting remarkable retention.  The other 2 subjects were identified to have visual anomalies which would have gone undetected without this research.

Subramaniam, A., Purushothaman, S., 1975. A case of hypohyon keratitis in an elephant. Madras Veterinary College Annual 33, 15-16.

Super, S.J., 1975. Optometric examination of the African elephant, Loxodonta africana africana, in south west Africa. Madogua 9, 45-51.
Abstract: Twenty-one immobilized elephants, optometrically examined in the Etosha National Park, exhibited very little refractive error.  "Super Retinoscopy," applying sunlight for external illumination, was used for the first time as a refractive technique.  Etorphine hydrochloride (M 99), the immobilizing agent instilled, caused non-reacting miotic pupils.  Gross anatomical observations were made on immobilized elephant's eyes as well as on enucleated eyes.

Buss, I.O., Estes, J.A., 1971. The functional significance of movements and position of the pinnae of the African elephant Loxodonta africana. Journal of Mammalogy 52, 21-27.
Abstract: Observations of wild African elephants (Loxodonta africana) in Uganda indicated that flapping and spreading the highly vascularized ears are probably important functions for heat dissipation.  Ear flapping increased as ambient temperatures rose and decreased or ceased during cold or rainy weather.  Rate of ear flapping was inversely related to wind velocity.  Spreading the ears reduced ear flapping, particularly when an elephant faced downwind.  Stimuli that elicited alertness, excitement or hostility caused elephants to raise their heads and spread their ears widely and rigidly, and large elephants occasionally flapped their ears loudly and sharply. Flapping and spreading the ears for heat dissipation are generally not interpreted as danger signals by other elephants.

Fain, A., 1970. A new anoetid living in the ear wax of an elephant (Acarina: Sarcoptiformes). Acta Zool Pathol Antverp 50, 173-177.

Marschner, C., 1970. Qualitative and quantitative studies on the olfactory bulb of elephants in comparison with that of man and pigs. Acta Anat (Basel) 75, 578-595.
Abstract: In this article, the side preferences of feeding-related trunk movements of free-ranging Asian elephants (Elephas maximus) were investigated for the first time. It is hypothesized that a functional asymmetry of the trunk is necessary to perform skillful feeding movements more efficiently. This might be connected with a corresponding hemispheric specialization. Video recordings of 41 wild elephants provided frequencies and durations of the following trunk-movement categories: object contact, retrieval, and reaching. In each category, individual side preferences were found. The strength of side preferences varied between the trunk-movement categories and the sexes. Mean durations of retrieval and reaching correlated negatively with the strength of side biases. Comparing the side preferences in the unpaired trunk with analogous phenomena in other unpaired grasping organs and in primate handedness. the authors discuss possible explanations for the evolution of asymmetries in unpaired grasping organs.

Rao, A.T., Acharjya, L.N., 1970. A case of fibrosarcoma in a baby elephant. Indian Veterinary Journal 47, 593.

McCullagh, K.G., Gresham, G.A., 1969. Eye lesions in the African elephant (Loxodonta africana). Research in Veterinary Science 10, 587-589.

Buttiker, W., 1967. First records of eye-frequenting Lepidoptera from India. Revue Suisse de Zoologie 74, 389-407.

Laws, R.M., 1967. Eye lens weight and age in the African elephant. East African Wildlife Journal 5, 46-52.
Abstract: Eye lens dry-weights have been determined for 543 African elephants from three populations in East Africa.  When plotted against estimated ages based on tooth replacement and wear criteria they indicate growth curves with rapid initial growth in lens weight, succeeded by a phase of rectilinear growth which apparently persists throughout life.    Parameters for the regressions of lens dry weight on age have been calculated by sex and locality.  Confidence limits are fitted and no significant difference in growth ratescan be demonstrated, except for a sex difference in the values for the a intercept.    Variability at age is slightly greater in males than females, but is little greater than is indicated by studies on other species using known-age animals.  This is taken to confirm the accuracy of the age criteria adopted and leads to conclusions on their precision.    It is suggested that this method might provide an objective check on the accuracy and precision of age estimates in other species.

Cave, A.J.E., 1963. Vocal communication in an elephant. Wildlife and Sport 3, 14-19.

Buss, I.O., 1962. The origin of certain sounds made by the elephant. Wildlife and Sport 3, 33-35.

 

 

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