anatomy

1. Bates L.A. and 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, sociallearning 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.

2. Bates L.W. and 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.

3. Bouley D.M., Alarcón C.N., Hildebrandt T., O'connell-Rodwell C.E. and . 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 Aug 15; [Epub ahead of print].
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.

4. Brown J.L., Somerville M., Riddle H.S. et al. 2007. Comparative endocrinology of testicular, adrenal and thyroid function in captive Asian and African elephant bulls.General and Comparative Endocrinology 151: 153-162.
Abstract: Concentrations of serum testosterone, cortisol, thyroxine (free and total T4), triiodothyronine (free and total T3) and thyroid stimulating hormone (TSH) were measured to assess adrenal and thyroid function as they relate to testicular activity and musth in captive elephants. Blood samples were collected approximately weekly from Asian (n = 8) and African (n = 12) bulls at seven facilities for periods of 4 months to 9.5 years. Age ranges at study onset were 8-50 years for Asian and 10-21 years for African elephants. Based on keeper logs, seven Asian and three African bulls exhibited behavioral and/or physical (temporal gland secretion, TGS, or urine dribbling, UD) signs of musth, which lasted 2.8 +/- 2.5 months in duration. Serum testosterone was elevated during musth, with concentrations often exceeding 100 ng/ml. Patterns of testosterone secretion and musth varied among bulls with no evidence of seasonality (P > 0.05). Only three bulls at one facility exhibited classic, well-defined yearly musth cycles. Others exhibited more irregular cycles, with musth symptoms often occurring more than once a year. A number of bulls (I Asian, 9 African) had consistently low testosterone (< 10 ng/ml) and never exhibited significant TGS or UD. At facilities with multiple bulls (n = 3), testosterone concentrations were highest in the oldest, most dominant male. There were positive correlations between testosterone and cortisol for six of seven Asian and all three African males that exhibited musth (range, r = 0.23-0.52; P < 0.05), but no significant correlations for bulls that did not (P > 0.05). For the three bulls that exhibited yearly musth cycles, TSH was positively correlated (range, r = 0.22-0.28; P < 0.05) and thyroid hormones (T3, T4) were negatively correlated (range, r = -0.25 to -0.47; P < 0.05) to testosterone secretion. In the remaining bulls, there were no clear relationships between thyroid activity and musth status. Overall mean testosterone and cortisol concentrations increased with age for all bulls combined, whereas thyroid activity declined. In summary, a number of bulls did not exhibit musth despite being of adequate physical maturity. Cortisol and testosterone were correlated in most bulls exhibiting musth, indicating a possible role for the adrenal gland in modulating or facilitating downstream responses. Data were generally inconclusive as to a role for thyroid hormones in male reproduction, but the finding of discrete patterns in bulls showing clear testosterone cycles suggests they may facilitate expression or control of musth in some individuals.

5. Helke K.L., Mankowski J.L. and Manabe Y.C. 2007. Animal models of cavitation in pulmonary tuberculosis.Tuberculosis (Edinb) 86: 337-348.
Abstract: Transmission of tuberculosis occurs with the highest frequency from patients with extensive, cavitary, pulmonary disease and positive sputum smear microscopy. In animal models of tuberculosis, the development of caseous necrosis is an important prerequisite for the formation of cavities although the immunological triggers for liquefaction are unknown. We review the relative merits and the information gleaned from the available animal models of pulmonary cavitation. Understanding the host-pathogen interaction important to the formation of cavities may lead to new strategies to prevent cavitation and thereby, block transmission.

6. Kellogg M.E., Burkett S., Dennis T.R. et al. 2007. Chromosome painting in the manatee supports Afrotheria and Paenungulata.BMC Evolutionary Biology 7.
Abstract: Sirenia (manatees, dugongs and Stellar's sea cow) have no evolutionary relationship with other marine mammals, despite similarities in adaptations and body shape. Recent phylogenomic results place Sirenia in Afrotheria and with elephants and rock hyraxes in Paenungulata. Sirenia and Hyracoidea are the two afrotherian orders as yet unstudied by comparative molecular cytogenetics. Here we report on the chromosome painting of the Florida manatee. Results: The human autosomal and X chromosome paints delimited a total of 44 homologous segments in the manatee genome. The synteny of nine of the 22 human autosomal chromosomes (4, 5, 6, 9, 11, 14, 17, 18 and 20) and the X chromosome were found intact in the manatee. The syntenies of other human chromosomes were disrupted in the manatee genome into two to five segments. The hybridization pattern revealed that 20 (15 unique) associations of human chromosome segments are found in the manatee genome: 1/15, 1/19, 2/3 (twice), 3/7 (twice), 3/13, 3/21, 5/21, 7/16, 8/22, 10/12 (twice), 11/20, 12/22 (three times), 14/15, 16/19 and 18/19. Conclusion: There are five derived chromosome traits that strongly link elephants with manatees in Tethytheria and give implicit support to Paenungulata: the associations 2/3, 3/13, 8/22, 18/19 and the loss of the ancestral eutherian 4/8 association. It would be useful to test these conclusions with chromosome painting in hyraxes. The manatee chromosome painting data confirm that the associations 1/19 and 5/21 phylogenetically link afrotherian species and show that Afrotheria is a natural clade. The association 10/12/22 is also ubiquitous in Afrotheria (clade I), present in Laurasiatheria (clade IV), only partially present in Xenarthra (10/12, clade II) and absent in Euarchontoglires (clade III). If Afrotheria is basal to eutherians, this association could be part of the ancestral eutherian karyotype. If afrotherians are not at the root of the eutherian tree, then the 10/12/22 association could be one of a suite of derived associations linking afrotherian taxa.

7. Kinahan A.A., Pimma S.L. and van Aarde R.J. 2007. Ambient temperature as a determinant of landscape use in the savanna elephant, Loxodonta africana.Journal of Thermal Biology 32: 47-58.
Abstract: Elephants occur in landscapes where temperatures can reach 50 degrees C. Due to their large size they may face physiological problems of dissipating heat during such high temperatures. In spite of this, no one seems to have considered ambient temperature as limiting landscape choices in elephants. We recorded hourly landscape use in free-ranging elephants using GPS collars. We also placed temperature data loggers in each of the landscapes, to obtain corresponding ambient temperatures for each hour. Our results suggest that elephants may select landscapes based on the rate at which temperatures changed and also for shade. We suggest that these selected variables provide a thermal benefit to individuals. As such, we propose that landscape use in elephants may be constrained by their thermal physiological requirements as well as other resources such as food and water.

8. Mills A. and Milewski A. 2007. Geophagy and nutrient supplementation in the Ngorongoro Conservation Area, Tanzania, with particular reference to selenium, cobalt and molybdenum.Journal of Zoology 271: 110-118.
Abstract: Wildlife and livestock in the Ngorongoro Conservation Area (NCA), Tanzania, commonly practise geophagy. We investigated the nutrient content of nine earth licks and adjacent topsoils in the NCA, and for comparative purposes, two salt pans in north-eastern Tanzania, licks in central Tanzania and a lick near Puerto Maldonado, Peru. The licks had no consistent pattern of nutrient enrichment relative to unutilized topsoils, although the Na content of licks was greater than that of the adjacent topsoils at all but one site. The three largest licks in the NCA (Gibbs Farm, Seneto and Ascent Road) were enriched relative to topsoils and global averages in Se (maximum of 4.7 mg kg), Co (maximum of 107 mg kg) and/or Mo (maximum of 7.4 mg kg). We suggest that licks do provide supplemental Na, but that Se, Co and/or Mo at the largest licks provide easily overlooked nutritional benefits and are perhaps the primary target for geophagy at these sites. Subsoil zones of clay deposition are likely to be enriched in various elements through illuviation or mineral precipitation from solution. Animals may use the taste of NaCl as a clue for locating such zones where they are likely to find a greater quantity of micronutrients relative to other soils. These findings have consequences for conservation and pastoralism in that these large licks may be key resources, providing micronutrients that are essential for maintaining the health and fecundity of animal as well as human populations in the region.

9. 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.

10. Ren L. and Hutchinson J. 2007. Three-dimensional locomotor dynamics of African (Loxodonta africana) and Asian (Elephas maximus) elephants.Comparative Biochemistry And Physiology A-Molecular & Integrative Physiology 146: S110-S111.
Abstract: Elephants do not trot or gallop, but can move smoothly to high speeds without changing their footfall pattern. Do they change gait? We measured the 3D centre of mass (CoM) motions and trunk rotations of three African elephants at West Midlands Safari Park, UK and two Asian elephants at Woburn Safari Park, UK using a novel multi-sensor met hod i ntegrating 3D accelerometers and 3D gyroscopes. Hundreds of continuous gait cycles were recorded in the field at different speeds. The CoM motions and mechanical energies in each stride cycle were calculated. The mechanical energy recovery was assessed at
different speeds.

11. Witter K., Egger G.F. and Boeck P. 2007. Renaut bodies in nerves of the trunk of the African elephant, Loxodonta africana.J Morphol 268: 414-422.
Abstract: Renaut bodies are loosely textured, cell-sparse structures in the subperineurial space of peripheral nerves, frequently found at sites of nerve entrapment. The trunk of the elephant is a mobile, richly innervated organ, which serves for food gathering, object grasping and as a tactile organ. These functions of the trunk lead to distortion and mechanical compression of its nerves, which can therefore be expected to contain numerous Renaut bodies. Samples of the trunk wall of an adult African elephant (Loxodonta africana) were examined histologically using conventional staining methods, immunohistochemistry, and lectin histochemistry. Architecture of nerve plexuses and occurrence of Renaut bodies in the elephant trunk were compared with those in tissues surrounding the nasal vestibule of the pig. Prominent nerve plexuses were found in all layers of the elephant trunk. Almost all (81%) nerve profiles contained Renaut bodies, a basophilic, discrete subperineurial layer resembling cushions around the nerve core. In contrast, Renaut bodies were seen in only 15% of nerve profiles in the porcine nasal vestibule. Within Renaut bodies, fusiform fibroblasts and round, ruff-like cells were placed into a matrix of acidic glycosaminoglycans with delicate collagen and very few reticular fibers. The turgor of this matrix is thought to protect nerves against compression and shearing strain. Renaut bodies are readily stained with alcian blue (pH 2.5) favorably in combination with immunohistochemical markers of nerve fibers. They should be regarded as a physiological response to repeated mechanical insults and are distinct from pathological alterations.

12. Benz A., Zenker W., Hildebrandt T.B., Weissengruber G. and Geyer H. 2006. Recent findings about the macroscopic and microscopic morphology of the elephants hooves (Elephantidae). Proceedings International Elephant Conservation & Research Symposium., 2006, pp. 38-41.

13. Bertschinger H., Delsink A., Kirkpatrick J.F. et al. 2006. Management of elephant populations in private South African game reserves with porcine zona pellucida vaccine. 2006 Proceedings American Association of Zoo Veterinarians, pp. 283-285.
Abstract: Control of African elephant populations has become an absolute necessity in a number of game reserves in southern Africa. The two main methods used to control populations so far are culling and translocation. Culling, besides being regarded as inhumane and unacceptable in many quarters, is not suitable for smaller populations. It requires that whole family units are culled simultaneously which could mean that in reserves with 10 to 50 elephants a considerable portion, if not the entire population, is killed. As far as translocation is concerned, limited new space is available for elephants. The only alternative to the two above options is to control the rate of reproduction. The porcine zona pellucida (pZP) vaccine has been used to successfully contracept wild horses and other wildlife species. Work on the contraception of African elephants was initiated in the Kruger National Park in 1995 when the potential for using the porcine zona pellucida (pZP) was investigated. Subsequently the first field trials on wild elephants were carried out in Kruger and the results clearly showed that elephants could be contracepted with the pZP vaccine, although the efficacy achieved was 80%. During these field trials safety and reversibility werecould be demonstrated. In 2000 an elephant contraceptive program was initiated at Makalali Private Game Reserve, RSA, which has become the flagship model for immunocontrol in African elephants. The preliminary findings have been reported in three publications.During the first year, all 18 cows that were individually identified and older than 12 yr of age were treated. During the next 4 yr the number of cows contracepted increased to 23 as young animals were added to the program. The standard vaccination procedure during the first year consisted of a primary vaccination (600 μg or 400 μg pZP with 0.5 ml Freund's modified complete adjuvant) followed by boosters (200 μg pZP with 0.5 ml Freund's incomplete adjuvant) at 3 to 6-wk intervals. Annual boosters to maintain antibody titers and contraceptive effect followed. To date, the success rate on cows that have passed reserve-specific intercalving period of 56 mo has been 100%. The population stabilized within 3 yr by which time when all cows that had been pregnant at the time of first vaccination in 2000 had calved. Once again safety during pregnancy (14 cows pregnant at 2-21 mo gestation when first treated gave birth to normal healthy calves) as well as side effects that were limited to occasional lumps at the site of vaccination could be shown. Following ground darting, behavioral patterns returned to pre-darting status within 2 days. During 2003 and 2004 most boosters were administered from a helicopter; whereas, previously they had been done from a vehicle or on foot. In all cases, drop-out darts were used. Time taken for vaccination from helicopter take-off to landing was about 30 min (1.5 min per cow; 30 min for total time). This required prior knowledge of the locations of family units or that an individual in each unit is radio-collared. Herds settled down much more quickly (1-2 days) than if darted from the ground. Since then we have vaccinated another 107 elephant cows in eight game reserves. The cow populations have ranged from 4 to 43. In one of the reserves, Mabula, RSA, two of the four cows vaccinated have passed the mean intercalving intervals of the reserve with neither of them producing a calf. Treatment at the remaining reserves was initiated in 2004 or 2005 and it is too early to evaluate results. The most difficult reserve in terms of the vaccination process was Welgevonden, RSA, (35 000 ha) with 43 cows. The reserve is mountainous and heavily wooded. None of the elephants were collared and individuals could not be easily identified on the day of primary vaccination. The total flying time during which individuals were identified and vaccinated was 4.5 hr. Administration of the first booster took about 2 hr to locate and vaccinate each cow. Between the first and second booster the first rains occurred, followed by the spring flush of the vegetation. By the time the second booster was attempted late in November, the trees all had foliage. Only half the cows were located and darted because the elephants were very difficult to spot under the tree canopies. The valuable lessons we learned from this were: 1) that helicopter vaccinations should be performed when most trees are bare, and 2) when larger populations are vaccinated repeatedly during the first year, one cow in each family unit should be radio-collared. This makes rapid location of each unit possible and cuts down on the major cost factor that is flying time. Elephant behavior is being monitored in all eight reserves where contraception is being applied. Because most of them have been contracepted recently, only the data from Makalali is available. The elephants at Makalali have been monitored intensively almost on a daily basis. To date, no anomalies in terms of aggressive or indifferent behavior with regards to nursing time, nursing behavior and calf proximity have been noted. No change in the cows' social hierarchy has been noted. Since January 2003, a total of 15 heats were observed in 10 cows (nine in 2003 and six in 2004) with four mating episodes. For the same period, 38 musth occasions were seen in five bulls (26 in 2003 and 12 in 2004). These occasions include musth displayed in the same bull during consecutive days or within the same musth cycle. The greatest occurrence of musth was recorded in the largest, dominant bull. Bulls were not observed harassing or separating cows off from their herds or calves as a result of increased estrous frequency. Thus, the Makalali program demonstrates that pZP does not cause herd fragmentation, harassment by bulls, change in rank and other negative behaviors normally associated with hormonal contraceptives. In conclusion we feel that it is important to emphasize the following points: The pZP vaccine can be used successfully to contracept African elephants The vaccine is safe during pregnancy and has no negative effect on birth or calf raising It has no side effects other than occasional swelling at the site of vaccination It is reversible Other than an increased incidence of heat no behavioral side effects were seen.

14. Brown J.L., Somerville M., Riddle H.S., Keele M. and Duer C. 2006. Comparative endocrinology of testicular and thyroid function in captive Asian and African elephant bulls. Proceedings International Elephant Conservation & Research Symposium., 2006, pp. 58-75.

15. Drews B., Göritz F., Hermes R. et al. 2006. Morphological and ultrasonographic characterization of the embryonic development in elephants. Proceedings International Elephant Conservation & Research Symposium., 2006, pp. 82-83.

16. Hildebrandt T.B., Hermes R., Ratanakorn P. et al. 2006. Ultrasonographic assessment and ultrasound-guided biopsy of the retropharyngeal lymph nodes in elephants. 2006 Proceedings American Association of Zoo Veterinarians, pp. 117-118.
Abstract: So far there are no valid diagnostic tools available for identifying latent carriers of endotheliotropic elephant herpes virus (EEHV). For this reason, the lateral retropharyngeal lymph node complex (LARELYNOC) of elephants, identified during postmortem studies as target organ for EEHV and suitable for transcutaneous biopsy, was grossly described. Transcutaneous ultrasound (3.5 MHz) was applied behind the ear region to identify the LARELYNOC containing up to four single lymph nodes on each side. The lymph node tissue is situated 20-50 mm below the skin surface. An ultrasonographic assessment of the LARELYNOC and two biopsies were performed on 39 healthy Asian elephants (Elephas maximus). Samples were tested for EEHV via PCR. Whole blood samples were also collected and tested for active EEHV infection. Lymph nodes were ultrasonographically classified as active (calculated mean volume=17.4 ± 6.9 cm3, P>0.001), inactive (calculated mean volume=3.1 ± 0.6 cm3, P<0.001), or chronic active (calculated mean volume=10.6 ± 1.0 cm3, P<0.05). Histology confirmed not only the presence of lymph tissue but also the ultrasonographically diagnosed reactivity status of the lymph node biospies. Although all samples including whole blood were found to be negative for the EEHV DNA particles, the successful development of this procedure in elephants could prove beneficial for the screening of not only latent EEHV infections but might also be a less dangerous alternative method for the diagnosis of zoonotic infections such as tuberculosis.

17. Reznikova Zh.I. 2006. The study of tool use as the way for general estimation of cognitive abilities in animals.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.

18. Schmitt D., Cartmill M., Griffin T.M., Hanna J.B. and Lemelin P. 2006. Adaptive value of ambling gaits in primates and other mammals.J Exp Biol 209 (Pt 11): 2042-2049.
Abstract: At speeds between the walk and the gallop, most mammals trot. Primates almost never trot, and it has been claimed that they transition directly from a walk to a gallop without any distinctive mid-speed running gait. If true, this would be another characteristic difference between the locomotion of primates and that of most other quadrupedal mammals. Presently, however, few data exist concerning the actual presence or absence of intermediate-speed gaits (i.e. gaits that are used between a walk and a gallop) in primates. Video records of running in twelve primate species reveal that, unlike most other mammals, all the primates studied almost exclusively adopt an 'amble'--an intermediate-speed running gait with no whole-body aerial phase--rather than trot. Ambling is also common in elephants and some horses, raising the question of why ambling is preferred over trotting in these diverse groups of animals. Mathematical analyses presented here show that ambling ensures continuous contact of the body with the substrate while dramatically reducing vertical oscillations of the center of mass. This may explain why ambling appears to be preferable to trotting for extremely large terrestrial mammals such as elephants and for arboreal mammals like primates that move on unstable branches. These findings allow us to better understand the mechanics of these unusual running gaits and shed new light on primate locomotor evolution.Department of Biological Anthropology and Anatomy, Duke University, Durham, NC 27710, USA. daniel_schmitt@baa.mc.duke.edu

19. Shakespeare A., Steyl J. and Strydom S. 2006. Investigating the depth of thermal burns in elephants.Journal Of The South African Veterinary Association-Tydskrif Van Die Suid-Afrikaanse Veterinere Vereniging 77: 134-140.

20. Shoshani J., Kupsky W.J. and Marchant G.H. 2006. Elephant brain. Part I: gross morphology, functions, comparative anatomy, and evolution.Brain Res Bull 70: 124-157.
Abstract: We report morphological data on brains of four African, Loxodonta africana, and three Asian elephants, Elephas maximus, and compare findings to literature. Brains exhibit a gyral pattern more complex and with more numerous gyri than in primates, humans included, and in carnivores, but less complex than in cetaceans. Cerebral frontal, parietal, temporal, limbic, and insular lobes are well developed, whereas the occipital lobe is relatively small. The insula is not as opercularized as in man. The temporal lobe is disproportionately large and expands laterally. Humans and elephants have three parallel temporal gyri: superior, middle, and inferior. Hippocampal sizes in elephants and humans are comparable, but proportionally smaller in elephant. A possible carotid rete was observed at the base of the brain. Brain size appears to be related to body size, ecology, sociality, and longevity. Elephant adult brain averages 4783 g, the largest among living and extinct terrestrial mammals; elephant neonate brain averages 50% of its adult brain weight (25% in humans). Cerebellar weight averages 18.6% of brain (1.8 times larger than in humans). During evolution, encephalization quotient has increased by 10-fold (0.2 for extinct Moeritherium, approximately 2.0 for extant elephants). We present 20 figures of the elephant brain, 16 of which contain new material. Similarities between human and elephant brains could be due to convergent evolution; both display mosaic characters and are highly derived mammals. Humans and elephants use and make tools and show a range of complex learning skills and behaviors. In elephants, the large amount of cerebral cortex, especially in the temporal lobe, and the well-developed olfactory system, structures associated with complex learning and behavioral functions in humans, may provide the substrate for such complex skills and behavior.

21. Siegal-Willott J., Isaza R., Johnson R. and Blaik M. 2006. Clinical evaluation of distal limb radiography and growth plate closure in the juvenile Asian elephant (Elephas maximus).
2006 Proceedings American Association of Zoo Veterinarians, pp. 181-182.
Abstract: The thoracic limb digits of 11 healthy juvenile Asian elephants (Elephas maximus) were evaluated radiographically to assess normal developmental anatomy. Parameters evaluated included: the location(s) of centers of ossification, relative age at time of phalangeal ossification, and relative times of growth plate closure in the bones of the distal forelimb. Specifically, the third phalanx (P3) of each digit was evaluated, as well as the first (P1) and second (P2) phalanges of the third digit (D3). A retrospective evaluation of radiographs from juvenile elephants was also done to augment the data set. This study reports the methods used to obtain high-quality radiographs of the elephant foot, the locations of centers of ossification based on radiographic evaluation, and the relative times of growth plate closure within the digital bones. The settings used to obtain the radiographs used in this study for P3 are presented in Table 1. Radiographs of D3, P1, and P2 were obtained in a similar manner, using a 45° angle for focal spot positioning. The kilovoltage power and milliampere seconds were adjusted as needed. Radiographic evaluation of the juvenile Asian elephants revealed variability in the shape of P3 based on age of the animal and degree of ossification of P3. The relative times of growth plate closure and number of ossifications were also determined. The information presented will help clinicians in radiographing elephants, interpreting foot radiographs, and recognizing normal versus abnormal anatomy. It will also help in aging juvenile elephants, investigating diseases and deaths, and recognizing normal patterns of toe and foot development.

22. Takahashi H., Yamashita M. and Shigehara N. 2006. Cranial photographs of mammals on the web: The Mammalian Crania Photographic Archive (MCPA2) and a comparison of bone image databases.Anthropological Science 114: 217-222.
Abstract: The Mammalian Crania Photographic Archive (MCPA2) is a website (http://1kai.dokkyomed.ac.jp/mammal/en/mammal.html) that includes a collection of 10,950 photographs of mammalian crania, which have been taken with a high-resolution digital camera. In the present report, we outline the characteristics of MCPA2 and how it was created, and make brief comparisons with several similar websites currently accessible via the internet. The archived MCPA2 materials include 1825 cranial specimens, ranging from insectivores to elephants, which have been macerated in Japan during the past 35 years and prepared for osteological study. Of the 16 orders represented in the database, primates comprise the major group with 704 specimens. Each cranium was placed with the orbitomeatal (Frankfort) or palatine plane horizontal, and was photographed in six perpendicular views from a long distance using a telephoto or telemacro lens. These long-distance shots decrease perspective distortion that lead to measurement errors when studying cranial profiles and landmark positions, and enable detailed observation and measurement of specific bony characteristics on a computer screen. From our website, images can be searched using (1) the taxonomic table, (2) Japanese name, (3) English name, and (4) scientific name. In the page of search results, in addition to the images, four caliper measurements and additional text (taxonomy, sex, and age) are available for every specimen.

23. Uemura Y., Asakuma S., Yon L. et al. 2006. Structural determination of the oligosaccharides in the milk of an Asian elephant (Elephas maximus).Comparative Biochemistry and Physiology A- Molecular and Integrative Physiology 145: 468-478.
Abstract: Milk of an Asian elephant (Elephas maximus), collected at 11 days post partum, contained 91 g/L of hexose and 3 g/L of sialic acid. The dominant saccharide in this milk sample was lactose, but it also contained isoglobotriose (Glc(alpha 1-3)Gal(beta 1-4)Glc) as well as a variety of sialyl oligosaccharides. The sialyl oligosaccharides were separated from neutral saccharides by anion exchange chromatography on DEAE-Sephadex A-50 and successive gel chromatography on Bio Gel P-2. They were purified by high performance liquid chromatography (HPLC) using an Amide-80 column and characterized by H-1-NMR spectroscopy. Their structures were determined to be those of 3'-sialyllactose, 6'-sialyllactose, monofucosyl monosialyl lactose (Neu5Ac(alpha 2-3)Gal(beta 1-4)[Fuc(alpha 1-3)]Glc), sialyl lacto-N-neotetraose c (LST c), galactosyl monosialyl lacto-N-neohexaose, galactosyl monofucosyl monosialyl lacto-N-neohexaose and three novel oligosaccharides as follows: Neu5Ac(alpha 2-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc (beta 1-3)Gal(beta 1-4)Glc, Neu5Ac(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)GlcNAc(beta-3)Gal(beta 1-4)Glc, and Neu5Ac(alpha 2-3)Gal(beta 1-4)[Fuc(alpha 1-3)] GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4)Glc. The higher oligosaccharides contained only the type II chain (Gal(beta 1-4)GlcNAc); this finding differed from previously published data on Asian elephant milk oligosaccharides.

24. Weissengruber G.E., Fuss F.K., Egger G. et al. 2006. The elephant knee joint: morphological and biomechanical considerations.Journal of Anatomy 208: 59-72.
Abstract: Elephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. In elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. In addition, the knee joint is affected frequently by arthrosis. Here we examined structures of the knee joint by means of standard anatomical techniques in eight African (Loxodonta africana) and three Asian elephants (Elephas maximus). Furthermore, we performed radiography in five African and two Asian elephants and magnetic resonance imaging (MRI) in one African elephant. Macerated bones of 11 individuals (four African, seven Asian elephants) were measured with a pair of callipers to give standardized measurements of the articular parts. In one Asian and three African elephants, kinematic and functional analyses were carried out using a digitizer and according to the helical axis concept. Some peculiarities of healthy and arthrotic knee joints of elephants were compared with human knees. In contrast to those of other quadruped mammals, the knee joint of elephants displays an extended resting position. The femorotibial joint of elephants shows a high grade of congruency and the menisci are extremely narrow and thin. The four-bar mechanism of the cruciate ligaments exists also in the elephant. The main motion of the knee joint is extension-flexion with a range of motion of 142 degrees. In elephants, arthrotic alterations of the knee joint can lead to injury or loss of the cranial (anterior) cruciate ligament. Anatomy, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria. gerald.weissengruber@vu-wien.ac.at

25. Weissengruber G.E., Egger G.F., Hutchinson J.R. et al. 2006. The structure of the cushions in the feet of African elephants (Loxodonta africana).Journal of Anatomy 209: 781-792.
Abstract: The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

26. Williams M.F. 2006. Morphological evidence of marine adaptations in human kidneys.Med Hypotheses 66: 247-257.
Abstract: Amongst primates, kidneys normally exhibiting lobulated, multipyramidal, medullas is a unique attribute of the human species. Although, kidneys naturally multipyramidal in their medullary morphology are rare in terrestrial mammals, kidneys with lobulated medullas do occur in: elephants, bears, rhinoceroses, bison, cattle, pigs, and the okapi. However, kidneys characterized with multipyramidal medullas are common in aquatic mammals and are nearly universal in marine mammals. To avoid the deleterious effects of saline water dehydration, marine mammals have adaptively thickened the medullas of their kidneys--which enhances their ability to concentrate excretory salts in the urine. However, the lobulation of the kidney's medullary region in marine mammals appears to be an adaptation to expand the surface area between the medulla and the enveloping outer cortex in order to increase the volume of marine dietary induced hypertonic plasma that can be immediately processed for the excretion of excess salts and nitrogenous waste. A phylogenetic review of freshwater aquatic mammals suggest that most, if not all, nonmarine aquatic mammals inherited the medullary pyramids of their kidneys from ancestors who originally inhabited, or frequented, marine environments. So this suggest that most, if not all, aquatic mammals exhibiting kidneys with lobulated medullas are either marine adapted--or are descended from marine antecedents. Additionally, a phylogenetic review of nonhuman terrestrial mammals possessing kidneys with multipyramidal medullas suggest that bears, elephants and possibly rhinoceroses, also, inherited their lobulated medullas from semiaquatic marine ancestors. The fact that several terrestrial mammalian species of semiaquatic marine ancestry exhibit kidneys with multipyramidal medullas, may suggest that humans could have, also, inherited the lobulated medullas of their kidneys from coastal marine ancestors. And a specialized marine diet in ancient human ancestry could, also, explain the reactivation and enumeration of corporeal eccrine sweat glands and the copious secretion of salt tears. The substantial loss of genetic variation in humans relative to other hominoid primates, combined with the apparent isolation of early Pliocene human ancestors from particular retroviruses that infected all other African primate species, may suggest that such a semiaquatic marine phase, during the emergence of Homo, may have occurred on an island off the coast of Africa during the early Pliocene.

27. Zuba J.R., Oosterhuis J.E. and Pessier A.P. 2006. The toenail "abscess" in elephants: treatment options including cryotherapy and pathologic similarities with equine proliferative pododermatitis (canker). 2006 Proceedings American Association of Zoo Veterinarians, pp. 187-190.
Abstract: Foot problems potentially represent the single most important clinical disease of captive elephants. Predisposing factors include obesity, lack of exercise, nail or sole overgrowth, improper foot care, poor hygiene, inappropriate enclosure surfaces, poor conformation, malnutrition and secondary skeletal disorders such as degenerative joint disease. Furthermore, factors such as elephant management philosophy, disposition of elephants, facilities and competency of staff in caring for elephant feet will contribute significantly to the foot health of captive animals. It is important to note that these conditions are rarely reported in free-ranging elephants. The elephant toenail abscess is characterized grossly by proliferative outgrowth of "crab meat-like" tissue that may acutely rupture through the surface of the nail wall and/or adjacent cuticle or sole. True abscess formation with localized collections of suppurative material is not a consistent clinical feature. In most cases, the inciting cause of these lesions are typically not found and are likely due to one or more of the predisposing factors listed above. Once established, these frustrating lesions require extensive, intensive and prolonged medical attention. If not cared for properly, these wounds may progress to phalangeal osteomyelitis and the need for surgical intervention. Sole abscesses are equally frustrating and difficult to manage with proposed etiologies similar to toenail lesions. There are no reports in the literature describing the pathology of the classic proliferative abscess tissue of the elephant nail abscess. Although variously interpreted as fibrous or granulation tissue, the authors are unaware of previous histologic descriptions of this tissue. Biopsy samples of toenail abscess tissue from two Asian elephants (Elephas maximus) at the San Diego Wild Animal Park (SDWAP) consisted of stratified squamous epithelium arranged in columns resembling horn tubules. The predominant histologic finding was marked, near diffuse, hydropic degeneration of keratinocytes. There were multifocal areas of suppurative inflammation with admixed bacterial colonies. Inflammatory foci comprised only a small portion of the lesion and were interpreted as the external surfaces of the biopsy with likely secondary bacterial colonization. Because descriptions of the normal histology of the elephant toenail could not be located, a grossly normal toenail from a different Asian elephant was obtained to compare histologic features with those of the toenail abscesses. Sections demonstrated formation of the toenail in a manner similar to that of the hoof of the horse and cattle with tubular, intertubular and laminar horn. Primary and secondary epidermal laminae were identified. Proliferative lesions of horn-producing epithelium associated with ballooning degeneration and inadequate keratinization of keratinocytes, have been described in horses as equine "canker" and coronary band dystrophy. Equine canker is most commonly observed in the hind feet of draft horses and begins in the frog sometimes with extension to the sole and hoof wall. Grossly, lesions are characterized by soft white papillary to "cauliflower-like" tissue associated with a foul odor. Similar to what is noted in elephant foot problems, predisposing factors for the development of equine canker include poor hygiene or wet environmental conditions. There is a lack of gross and histologic description of the normal nail and sole tissue of the elephant and further investigations are warranted. A review of the anatomy and histology of the normal equine hoof may provide a basic understanding of the elephant nail until more specific and detailed elephant information is available. From our investigation, the authors offer that a more accurate description of the elephant toenail abscess would be proliferative pododermatitis, the term synonymous with equine canker. A more colloquial term such as "elephant canker" may be appropriate, as well. Canker in the horse is an uncommon but difficult to treat disease of the hoof. Historically, treatment options for elephant toenail abscesses include corrective trimming, superficial debridement and application of topical disinfectants or antibiotics. Others have constructed innovative sandals to treat and protect the affected sole or nail with success. The use of regional intravenous perfusion of the affected limb with antibiotics has also been successful. Since the elephant nail abscess now appears to be histologically and clinically comparable to equine canker, this novel characterization of an old disease may offer unique insight for treatment. In the least, it has provided our practice with a new list of treatment options and experienced equine clinicians for consultation who have been managing patients with a similar disease for many years. One of the Asian elephants at the SDWAP has had chronic toenail abscesses for over 2 yr. Radiographs of the affected digits, as reported by others to assess degree of involvement, have fortunately been negative for evidence of osteomyelitis. Several bacterial and fungal cultures of deep tissue biopsies and swabs of affected lesions have resulted in a mixture of organisms with no consistent single etiologic agent. Biopsies were found negative for presence of viral DNA (elephant papillomavirus and herpesvirus) by PCR. Typical elephant foot care at the SDWAP includes trimming and debriding with hoof knives, foot soaks and topical antibiotics. Although difficult, attempts are made in keeping the affected foot clean and dry. Following recommendations for the treatment of equine canker, we recently implemented the routine use of cryotherapy in all elephants with proliferative pododermatitis with improved success in the control and recession of exuberant nail lesions. The proliferative tissue of the nail is first cleaned then disinfected, debrided, trimmed with hoof knives and allowed to dry. Modified brass branding tools with contact surfaces of variable size (2-5 cm diameter) and shape (round or ovoid) are placed into liquid nitrogen (-196 C) for several minutes and then placed directly on the cankerous tissue for 30-60 sec. This process is then repeated 4-5 min later, following a complete thaw of tissue. Within 24 hr, the cryoburned tissue becomes macerated and necrotic and is readily removed with gentle scrubbing. Cryotherapy offers the advantage of destroying tissue to a deeper level than trimming alone and provides hemostasis, as well. Because of decreased sensation at the cryotherapy treatment site, a memorable painful event is avoided and the elephant patient is more routinely accepting of this technique. With the use of hoof knives, we typically remove 2-3 mm of proliferative tissue before the patient refuses further treatment, presumably due to discomfort. With cryotherapy, we are able to remove an additional 3-5 mm of tissue by cell freezing and necrosis. The result is quicker resolution of cankerous lesions without the need for aggressive, and potentially painful, interventions. In conclusion, it appears that elephant nail abscesses can best be described as proliferative pododermatitis, or canker, as is seen in other species. Further gross and microscopic descriptions of normal and pathologic nail or sole lesions are necessary. Routine cryotherapy has shown promise in the treatment of these chronic, frustrating and potentially devastating lesions of our captive elephants.

28. Allen W.R., Mathias S. and Ford M. 2005. Placentation in the African elephant, Loxodonta africana. IV. Growth and function of the fetal gonads.Reproduction 130: 713-720.
Abstract: The gonads, both ovaries and testes, of 44 elephant fetuses weighing 0.09-112 kg (6.1-21.3 months gestation) were examined grossly and histologically. As in equids, elephant fetal gonads undergo a phase of marked growth and enlargement during the second half of gestation, which is more pronounced in ovaries than testes due to growth and antrum formation of numerous follicles in the former. Stromal cells undergo hypertrophy and transformation to form zones of interstitial cells that are associated with the enlarged follicles in the ovaries and in which the primitive seminiferous tubules are embedded in the testes. The interstitial cells have the capacity to synthesize 5alpha-dihydroprogesterone and other 5alpha-reduced progestagens from cholesterol and pregnenelone and the hypothesis is raised that these fetal gonadal progestagens may supplement significantly the progestagens secreted by the multiple large corpora lutea of pregnancy in the elephant.

29. Benz A. 2005. The elephant's hoof: macroscopic and microscopic morphology of defined locations under consideration of pathological changes. Inaugural Dissertation Vetsuisse-Fakultät Universität Zürich.

30. Benz A., Zenker W., Hildebrandt T.B., Weissengruber G.E. and Geyer H. 2005. About the macroscopic and microscopic morphology of elephants' hooves (Elephantidae). Erkrankungen der Zootiere. Verhandlungsbericht des Internationalen Symposiums über die Erkrankungen der Zoo- und Wildtiere / International Symposium on Diseases of Zoo and Wild Animals, pp. 164-166.

31. Benz A. 2005. The elephant's hoof: Macroscopic and microscopic morphology of defined locations under consideration of pathological changes. University of Zurich, Zurich.

32. Clauss M., Robert N., Walzer C., Vitaud C. and Hummel J. 2005. Testing predictions on body mass and gut contents: dissection of an African elephant Loxodonta africana Blumenbach 1797.Eur J Wildl Res 51: 291-294.
Abstract: The values reported in the literature for the total gastrointestinal tract (GIT) content mass of elephants are lower than expected from interspeci.c mammalian regression. This .nding agrees with theoretical considerations that elephants should have less capacious GITs than other herbivorous mammals, resulting in short ingesta retention times. However, the data on elephants was so far derived from either diseased zoo specimens or free-ranging animals subjected to an unknown hunting stress. In this study, we weighed the wet contents of the GIT segments of a captive African elephant that was euthanased because of a positive serological tuberculosis test, but that was clinically healthy, did not show a reduced appetite, and ingested food up to the time of euthanasia. The animal weighed 3,140 kg and its total gut contents were 542 kg or 17% of body mass. This is in close accord with the published mammalian herbivore regression equation of Parra (Comparison of foregut and hindgut fermentation in herbivores. In: Montgomery GG (ed) The ecology of arboreal folivores. Smithsonian Institution Press, Washington DC, pp205-230, 1978) and contradicts the notion that elephants have comparatively less capacious gastrointestinal tracts. Data on the individual gut segments, however, do support earlier suspicions that elephants have a comparatively less capacious caecum and a disproportionally capacious colon.

33. Gunther B., Morgado E. and Cocina M. 2005. [Homeostatic range of the oxidative metabolism: 60 years of integrative fisiometry].Rev Med Chil 133: 362-370.
Abstract: The energetic metabolism and its relationship with body weight generated a vivid controversy, since the Rubner's surface law was introduced into biology. Recently, the multifactor theory (Darveau et al) has caused again a revival of this polemic topic. Moreover, the investigations concerning metabolism and body weight include all terrestrial mammals, from the shrew (3 grams) to the elephant (three tons). The corresponding allometric exponent for standard metabolic rate, both theoretical and empirical, fluctuates around an average value of 0.75, in contrast with the surface law, which postulated a value of 0.67. The "metabolic range" (rest vs maximal exercise) does vary from 1 to 10, due to the prevalent influence of the skeletal muscle activity. Recent investigations have emphasized the fact that the allometric exponent is not unique (0.75), but it should be subjected to statistical variability, both in standard and in maximal exercise.

34. Hakeem A.Y., Hof P.R., Sherwood C.C. et al. 2005. Brain of the African elephant (Loxodonta africana): Neuroanatomy from magnetic resonance images.The Anatomical Record Part A 287A: 1117-1127.
Abstract: We acquired magnetic resonance images of the brain of an adult African elephant, Loxodonta africana, in the axial and parasagittal planes and produced anatomically labeled images. We quantified the volume of the whole brain (3,886.7 cm3) and of the neocortical and cerebellar gray and white matter. The white matter-to-gray matter ratio in the elephant neocortex and cerebellum is in keeping with that expected for a brain of this size. The ratio of neocortical gray matter volume to corpus callosum crosssectional area is similar in the elephant and human brains (108 and 93.7, respectively), emphasizing the difference between terrestrial mammals and cetaceans, which have a very small corpus callosum relative to the volume of neocortical gray matter (ratio of 181-287 in our sample). Finally, the elephant has an unusually large and convoluted hippocampus compared to primates and especially to cetaceans. This may be related to the extremely long social and chemical memory of elephants.

35. Mobasheri A., Gent T.C., Womack M.D. et al. 2005. Quantitative analysis of voltage-gated potassium currents from primary equine (Equus caballus) and elephant (Loxodonta africana) articular chondrocytes.Am J Physiol Regul Integr Comp Physiol 289: 172-180.
Abstract: Quantitative analysis of voltage-gated potassium currents from primary equine (Equus caballus) and elephant (Loxodonta africana) articular chondrocytes. Am J Physiol Regul Integr Comp Physiol 289: R172-R180, 2005. First published March 31, 2005; doi:10.1152/ajpregu.00710.2004.-In this comparative study, we have established in vitro models of equine and elephant articular chondrocytes, examined their basic morphology, and characterized the biophysical properties of their primary voltage-gated potassium channel (Kv) currents. Using whole cell patch-clamp electrophysiological recording from first-expansion and first-passage cells, we measured a maximum Kv conductance of 0.15 ± 0.04 pS/pF (n =10) in equine chondrocytes, whereas that in elephant chondrocytes was significantly larger (0.8 ± 0.4 pS/pF, n = 4, P = 0.05). Steady-state activation parameters of elephant chondrocytes (V1/2 = -22 ± 6 mV, k =11.8 ±3 mV, n = 4) were not significantly different from those of horse chondrocytes (V1/2 = - 12.5 ± 4.3 mV, k = 12 ± 2, n =10). This suggests that there would be slightly more resting Kv activation in elephant chondrocytes than in their equine counterparts. Kinetic analysis revealed that both horse and elephant chondrocyte Kv currents had similar activation and inactivation parameters. Pharmacological investigation of equine chondrocyte Kv currents showed them to be powerfully inhibited by the potassium channel blockers tetraethylammonium and 4-aminopyridine but not by dendrotoxin-I. Immunohistochemical studies using polyclonal antibodies to Kv1.1-Kv1.5 provided evidence for expression of Kv1.4 in equine chondrocytes. This is the first electrophysiological study of equine or elephant chondrocytes. The data support the notion that voltage-gated potassium channels play an important role in regulating the membrane potential of articular chondrocytes and will prove useful in future modeling of electromechanotransduction of fully differentiated articular chondrocytes in these and other species.

36. Natiello M., Lewis P. and Samuelson D. 2005. Comparative anatomy of the ciliary body of the West Indian manatee (Trichechus manatus) and selected species.Vet Ophthalmol 8: 375-385.
Abstract: OBJECTIVE: To examine the anatomy of the ciliary body in the West Indian manatee (Trichechus manatus), paying close attention to its vascularization and to compare to those of its distant relative, the African elephant (Loxodonta africana), the amphibious hippopotamus (Hippopotamus amphibius) and the aquatic short-finned pilot whale (Globicephala macrorhynchus). PROCEDURE: Specimens from each species were preserved in 10% buffered formalin, and observed stereomicroscopically before being embedded in paraffin, sectioned and stained by Masson trichrome, hematoxylin and eosin, and periodic acid-Schiff for light microscopic evaluation. RESULTS: The network of blood vessels in the ciliary processes of the West Indian manatee appear to have an intricate pattern, especially with regard to venous outflow. Those of the elephant are slightly less complex, while those of the hippopotamus and whale have different vascular patterns within the ciliary body. Musculature within the ciliary body is absent within the manatee and pilot whale. CONCLUSIONS: In general, there appears to be a direct relationship between the increased development of vasculature and the loss of musculature within the ciliary bodies of the aquatic and amphibious mammals presently studied. Specifically, the ciliary body of the West Indian manatee has a comparatively unique construction, especially with regard to its vasculature.

37. Osthoff G., De Waal H.O., Hugo A., de Wit M. and Botes P. 2005. Milk composition of a free-ranging African elephant (Loxodonta africana) cow during early lactation.Comparative Biochemistry and Physiology A- Molecular and Integrative Physiology 141: 223-229.
Abstract: Only one study previously reported comprehensively on the composition of African elephant's (Loxodonta africana) milk that was collected from 30 dead animals. In the current study milk was obtained from a tame but free-ranging African elephant cow without immobilization during the period when she was 4-47 days postpartum. At the respective collection times the nutrient content was 21.8 and 25.0 g protein; 56.0 and 76.0 g fat, 71.1 and 26.0 g sugars per kilogram of milk. The protein fraction, respectively, consisted of 10.0 and 14.0 g caseins/kg milk and of 11.8 and 11 g whey proteins/kg milk. During lactation the lactose content dropped from 52.5 to 11.8 g/kg milk, while the oligosaccharide content increased from 11.8 to 15.2 g/kg milk. The oligosaccharide was characterized as a galactosyllactose, which is digestible by cellulase. Electrophoresis and identification of protein bands showed a similar migrating sequence of proteins as seen in cow's milk, but some of the corresponding proteins were less negatively charged. The lipid fraction contains a high content of capric and lauric acids, approximately 60% of the total fatty acids, and low content of myristic, palmitic and oleic acids.

38. Perez-Barberia F.J. and Gordon I.J. 2005. Gregariousness increases brain size in ungulates.Oecologia 145: 41-52.
Abstract: The brain's main function is to organise the physiological and behavioural responses to environmental and social challenges in order to keep the organism alive. Here, we studied the effects that gregariousness (as a measurement of sociality), dietary habits, gestation length and sex have on brain size of extant ungulates. The analysis controlled for the effects of phylogeny and for random variability implicit in the data set. We tested the following groups of hypotheses: (1) Social brain hypothesis-gregarious species are more likely to have larger brains than non-gregarious species because the former are subjected to demanding and complex social interactions; (2) Ecological hypothesis-dietary habits impose challenging cognitive tasks associated with finding and manipulating food (foraging strategy); (3) Developmental hypotheses (a) energy strategy: selection for larger brains operates, primarily, on maternal metabolic turnover (i.e. gestation length) in relation to food quality because the majority of the brain's growth takes place in utero, and finally (b) sex hypothesis: females are expected to have larger brains than males, relative to body size, because of the differential growth rates of the soma and brain between the sexes. We found that, after adjusting for body mass, gregariousness and gestation length explained most of the variation in brain mass across the ungulate species studied. Larger species had larger brains; gregarious species and those with longer gestation lengths, relative to body mass, had larger brains than non-gregarious species and those with shorter gestation lengths. The effect of diet was negligible and subrogated by gestation length, and sex had no significant effect on brain size. The ultimate cause that could have triggered the co-evolution between gestation length and brain size remains unclear.

39. Roca A.L. and O'Brien S.J. 2005. Genomic inferences from Afrotheria and the evolution of elephants.Current Opinion in Genetics and Development 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.

40. Sanna M.T., Manconi B., Castagnola M. et al. 2005. Functional and structural characterization of the myoglobin from the polychaete Ophelia bicornis.Biochem J 389: 497-505.
Abstract: The myoglobin of the polychaete annelid Ophelia bicornis was isolated, purified to homogeneity and characterized. The primary structure, obtained from cDNA and protein sequencing, consists of 139 amino acid residues. The alignment with other globin sequences showed that O. bicornis myoglobin misses the pre-A helix and the first six residues of the A helix. The presence of a PheB10-GlnE7 haem distal residue pair is in agreement with the measured oxygen affinity (P50=0.85 mmHg; 1 mmHg=0.133 kPa) and the only slightly higher autoxidation rate constant (0.28 h(-1)) with respect to that of the sperm whale myoglobin mutant E7 His-->Gln (0.21 h(-1)) and to elephant myoglobin (0.1 h(-1)). Oxygen-binding co-operativity was found to be absent under all the examined experimental conditions. The resistance of O. bicornis myoglobin towards autoxidation seems to confirm the important role of part of the A helix in the stability of the globin. The higher pKa of the acid-alkaline ferric transition of O. bicornis with respect to Asian elephant myoglobin, as well as the higher absorbance ratio of its ferric form to the oxy form measured in the Soret region (gammamet/gammaoxy) with respect to that of the African elephant myoglobin, suggested a stronger interaction between the distal glutamine and the water molecule at the sixth co-ordinate position.

41. Shoshani J. and 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.

42. Sitati N.W., Walpole M.J. and Leader-Williams N. 2005. Factors affecting susceptibility of farms to crop raiding by African elephants: using a predictive model to mitigate conflict.Journal of Applied Ecology 42: 1175-1182.
Abstract: 1. Crop raiding by African elephants Loxodonta africana erodes local tolerance for elephants and thereby impedes conservation efforts, so solutions are urgently required. Within conflict zones, crop raiding is not distributed equally amongst farms, which may be a result of variation in local physical or geographical factors, or in farmers' efforts to defend their fields. Understanding the efficacy of local conflict mitigation methods is important, but few quantitative evaluations exist.
2. Using a comparative survey of raided and non-raided farms in Transmara
District, Kenya, and multivariate logistic and linear regression analyses, we explored a range of factors affecting (i) the susceptibility of farms to elephant crop raiding and (ii) the amount of crop damage once elephants had entered a field.
3. The results revealed that farms that had been habitually raided in the past were more likely to be raided during the study period, as were those that were larger and bordered by hedges or fences. Greater guarding effort increased the likelihood that elephants were detected prior to entry and decreased the likelihood of successful crop raiding, as did the use of fire and noise.
4. However, there was an interaction between physical and human factors; larger farms used more advanced barrier methods at the expense of guarding effort. Farmers' efforts did not appear to diminish the damage inflicted once elephants had entered a field.
5. A subsequent experimental test confirmed these results; the application of enhanced early warning and guarding effort on previously raided farms reduced incidents of crop raiding by 89.6% over 2 years in comparison with a control group of farms.
6. Synthesis and applications. These results suggest that early detection of elephants approaching fields, increased guarding effort, and the use of active deterrents could form the basis of an effective mitigation strategy regardless of location and the physical attributes of a farm. Validating the results of predictive models through participatory mitigation trials serves to demonstrate effective solutions to farmers themselves. Researchers and practitioners should be encouraged to replicate such field trials over broader spatial and temporal scales and to find means to encourage farmers to take up appropriate solutions.

43. Weissengruber G.E., Egerbacher M. and Forstenpointner G. 2005. Structure and innervation of the tusk pulp in the African elephant (Loxodonta africana).J Anat 206: 387-393.
Abstract: African elephants (Loxodonta africana) use their tusks for digging, carrying and behavioural display. Their healing ability following traumatic injury is enormous. Pain experience caused by dentin or pulp damage of tusks seems to be negligible in elephants. In this study we examined the pulp tissue and the nerve distribution using histology, electron microscopy and immunhistochemistry. The results demonstrate that the pulp comprises two differently structured regions. Randomly orientated collagen fibres characterize a cone-like part lying rostral to the foramen apicis dentis. Numerous nerve fibres and Ruffini endings are found within this cone. Rostral to the cone, delicate collagen fibres and large vessels are orientated longitudinally. The rostral two-thirds of the pulp are highly vascularized, whereas nerve fibres are sparse. Vessel and nerve fibre distribution and the structure of connective tissue possibly play important roles in healing and in the obviously limited pain experience after tusk injuries and pulp alteration. The presence of Ruffini endings is most likely related to the use of tusks as tools. Institute of Anatomy, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria. gerald.weissengruber@vu-wien.ac.at

44. Yokoyama S., Takenaka N., Agnew D.W. and 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.

45. Boy S.C. and Steenkamp G. 2004. Neural innervation of the tusk pulp of the African elephant (Loxodonta africana).Veterinary Record 154: 372-374.

46. Bulte E., Damania R., Gillson L. and Lindsay K. 2004. Space-The final frontier for economists and elephants.Science 306: 420-421.
Abstract: At the Convention on International Trade in Endangered Species this month , Namibia is asking for an annual quota for the sale of ivory that is "accumulated from natural and management-related mortalities." The discussion is likely to be steeped in controversy, not least because of the complexity of the economic and ecological arguments involved. Managing elephant populations and evaluating the sustainability of the ivory trade require not only detailed economic analyses, but also recognition of the ecological complexities that influence decisions about elephant management. Understanding the economics of natural resources is crucial in such policy deliberations. So-called bioeconomic modeling- which describes interactions between commodity markets and biological populations such as elephant populations-has provided useful insights into two principal aspects of the ivory trade. First, bioeconomic modeling has shown that poaching and legal harvesting of ivory are not independent, although the nature of this interrelationship is still disputed. Some economists argue that banning a legal ivory trade might give an impetus to the black market and boost poaching. Others suggest that legal harvesting and trade may facilitate the "laundering" of illegal products- a potentially important but untested hypothesis. Second, economists have debated the effects that revenues from the ivory trade might have on conservation. On the one hand, it can be argued that ivory sales might provide incentives for governments to carefully manage the resource. For example, governments may be encouraged to invest in the monitoring of elephant populations, to enforce laws against illegal hunting and poaching, and to set aside land as elephant habitat [the species "earns its way". In the absence of such revenues, with growing elephant and human populations competing for land, it has been pointed out that wildlife may be exploited unsustainably, and that habitat will be converted to other more lucrative purposes by local people or investors. Conversely, recent developments in political economics emphasize that high commodity prices for ivory may be bad for conservation. High prices may unleash forms of "rent seizing" and patronage politics whereby vested interests seek to dismantle the protective institutions that limit their ability to grab the resource. Notwithstanding these contributions and the conflicting signals they send, economic models of elephant management and the ivory trade have failed to capture several essential elements.

47. Carter A.M., Enders A.C., Kunzle H., Oduor-Okelo D. and Vogel P. 2004. Placentation in species of phylogenetic importance: The Afrotheria.Animal Reproduction Science 82-83: 35-48.
Abstract: Afrotheria, one of four mammalian superorders, comprises elephants, sea cows, hyraxes, aardvark, elephant shrews, tenrecs and golden moles. Their placentas either form an equatorial band or are discoid in shape. The interhemal region, separating fetal and maternal blood, is endotheliochorial in elephants, aardvark and possibly the sea cows, but hemochorial in the remaining orders. There is a secondary epitheliochorial placenta in elephant shrews while a similar structure in tenrecs erodes maternal tissues. Specialized hemophagous regions are a striking characteristic of some of these placentas yet absent in hyraxes, elephant shrews, and golden moles. It is possible that the common ancestor of the Afrotheria had an endotheliochorial placenta. Establishment of a hemochorial condition, as seen in rock hyraxes, elephant shrews, tenrecs, and golden moles, would be a more recent development. The elephant, manatee, and aardvark all have circumferential placentas. Thus the formation of a discoid placenta with a more or less extensive secondary placenta in elephant shrews and tenrecs would also be a derived state.

48. Carter A.M. and Enders A.C. 2004. Comparative aspects of trophoblast development and placentation.Reproductive Biology and Endocrinology 2.
Abstract: Based on the number of tissues separating maternal from fetal blood, placentas are classified as epitheliochorial, endotheliochorial or hemochorial. We review the occurrence of these placental types in the various orders of eutherian mammals within the framework of the four superorders identified by the techniques of molecular phylogenetics. The superorder Afrotheria diversified in ancient Africa and its living representatives include elephants, sea cows, hyraxes, aardvark, elephant shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and sloths, diversified in South America. All placentas examined from members of these two oldest superorders are either endotheliochorial or hemochorial. The superorder Euarchontoglires includes two sister groups, Glires and Euarchonta. The former comprises rodents and lagomorphs, which typically have hemochorial placentas. The most primitive members of Euarchonta, the tree shrews, have endotheliochorial placentation. Flying lemurs and all higher primates have hemochorial placentas. However, the lemurs and lorises are exceptional among primates in having epitheliochorial placentation. Laurasiatheria, the last superorder to arise, includes several orders with epitheliochorial placentation. These comprise whales, camels, pigs, ruminants, horses and pangolins. In contrast, nearly all carnivores have endotheliochorial placentation, whilst bats have endotheliochorial or hemochorial placentas. Also included in Laurasiatheria are a number of insectivores that have many conserved morphological characters; none of these has epitheliochorial placentation. Consideration of placental type in relation to the findings of molecular phylogenetics suggests that the likely path of evolution in Afrotheria was from endotheliochorial to hemochorial placentation. This is also a likely scenario for Xenarthra and the bats. We argue that a definitive epitheliochorial placenta is a secondary specialization and that it evolved twice, once in the Laurasiatheria and once in the lemurs and lorises.

49. Enders A.C. and Carter A.M. 2004. What can comparative studies of placental structure tell us?--A review.Placenta Suppl A: 3-9.
Abstract: The diversity of placental structures in Eutherian mammals is such that drawing generalizations from the definitive forms is problematic. There are always areas of reduced interhaemal distance whether the placenta is epitheliochorial, synepitheliochorial, endotheliochorial or haemochorial. However, the thinning may be achieved by different means. The presence of a haemophagous area as an iron transport facilitator is generally associated with endotheliochorial placentae but is also found in sheep and goats (synepitheliochorial) and in tenrecs and hyaenas (haemochorial). Although similar chorioallantoic placentae are found within families, structure begins to diverge at the ordinal level and there is little correlation at the supraordinal level of phylogeny. Differences in formation and function of the yolk sac provide additional variation. There would appear to be considerable adaptive pressure for development or retention of the haemochorial type of chorioallantoic placenta. This type of placenta has several possible drawbacks including more ready passage of fetal cells to the maternal organism and, should the haemochorial condition be achieved early,oxidative stress. At any rate no animal larger than the human and gorilla has this type of placenta. The endotheliochorial condition is found in animals as large as the bears, manatee and elephants. In addition to the ungulates, the epitheliochorial condition is present in the largest animals with the longest gestation periods, the whales. Considering the length of time since the early stages of mammalian evolution, it is probable that few unmodified structural features are present in any currently surviving mammal. Nevertheless, more complete studies of divergent types of mammalian placenta should help our understanding of mammalian interrelationships as well as placental function.

50. Gobbel L., Fischer M.S., Smith T.D., Wible J.R. and 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

51. Hatfield J.R., Samuelson D.A., Lewis P.A. and 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.

52. Lamps L.W., Smoller B.R., Goodwin T.E. and Rasmussen L.E.L. 2004. Hormone receptor expression in interdigital glands of the Asian elephant (Elephas maximus).Zoo Biology 23: 463-469.
Abstract: Recently, our group performed the first histologic, histochemical, and immunohistochemical analysis of eccrine-type interdigital glands in the Asian elephant (Elephas maximus) (Lamps et al. [2001] Res Vet Sci 71:197-200). Since morphologically similar human eccrine glands express reproductive hormone receptors (including androgen, estrogen, and progesterone receptors), the purpose of the current study was to determine whether interdigital eccrine glands in the Asian elephant contain these same hormone receptors. Necropsy samples of interdigital areas from two adult Asian elephants (one male and one female) were obtained. Immunohistochemical staining was performed for estrogen, progesterone, and androgen receptor proteins. Immunoreactivity to all three receptor proteins was seen in a nuclear distribution in eccrine glands from both samples. This staining pattern is similar to that seen in human eccrine glands and tumors of eccrine derivation, although the significance of the receptor protein expression is unknown. The immunoreactivity of elephant interdigital glandular epithelium with monoclonal antibodies raised to human receptor proteins also suggests a high degree of phylogenetic conservation of these proteins between Asian elephants and humans. Despite detailed morphologic characterization, the function of these glands remains unclear. Further studies are needed to elucidate the function of these glands, the possible relationship between hormone receptor expression and circulating hormone levels, and the potential role of these glands in chemical communication in Asian elephants.

53. Meyer J.M., Walker S.L., Freeman E.W., Steinetz B.G. and Brown J.L. 2004. Species and fetal gender effects on the endocrinology of pregnancy in elephants.General and Comparative Endocrinology 138: 263-270.
Abstract: Quantitative and temporal progestin profiles vary during gestation in the elephant, sometimes making it difficult to determine if a pregnancy is progressing normally. The aim of the present study was to determine if circulating progestin variability was related to species or fetal gender effects. A similar comparison also was conducted for secretory profiles of prolactin, relaxin, and cortisol. Overall mean progestin concentrations during gestation in Asian (n = 19) and African (n = 8) elephants were similar; however, the temporal profiles differed (P < 0.001). Concentrations were higher in African elephants during the first half of pregnancy, but then declined to levels below those observed in Asian elephants (P < 0.05). There also was a fetal gender effect in Asian, but not African elephants. Progestin concentrations were higher in Asian cows carrying male calves (n = 9) as compared to those carrying females (n = 10) (P < 0.001). Overall prolactin concentrations were higher in Asian than in African elephants between 8 and 15 months of gestation (P < 0.001). There were no species differences in the secretory patterns of relaxin. Cortisol was relatively stable until the end of gestation when significant surges were observed, mainly between 8 and 11 days before parturition, and again on the day of birth. In sum, a comparison of progestin patterns between Asian and African elephants identified notable differences related to species and fetal gender. A role for cortisol in the initiation of parturition also was inferred from these data. From a practical standpoint, understanding the factors affecting gestational hormone characteristics and recognizing what the species differences are will help en