Significance of Various Internal and External Organs
Evolutionary History and Sub-Species
Introduction to Elephants - some general facts
Dr. Jacob V. Cheeran
Elephants have always been fascinating to human beings
because of their various peculiarities. Listed below are some
interesting facts about elephants.
- Elephants belong to the family
Proboscidae. In India, elephants are found in South India,
North-eastern India and Himalayan valleys and Orissa.
- Asian elephants are of five strains
and they are Indian, Burmese, Ceylonese, Sumatran and
- An Asian cow elephant weighs 2.5 - 3.5
tonnes and a bull weighs 3.5 to 5 tonnes.
- Bull elephants without tusks are
- Size of the neck is not proportionate
to that of the head and so elephants have short necks to
balance their huge head.
- The elephant is one among a few
animals that use tools in their day-to-day lives. A few
examples of such animals are discussed. A species of vulture
uses a stone to break ostrich eggs. Some otters found in the
Californian seas, use a stone to break open clam shells. A
woodpecker sometimes uses a stick to stir insects hiding in
a hole. Monkeys use a blade of grass to draw out ants from a
hole. An elephant uses a twig to scratch itself and can
learn to manipulate a variety of objects, to carry out a
variety of activities.
- Elephants have nails rather than
hooves. Most of the elephants have 18 nails, 5 in each of
the front legs and 4 in each of the hind legs and very
rarely 20 nails (5 nails each, on the hind and fore legs).
The foot pad has a thick fat cushion, to provide a good
grip, while walking over marshy and slushy grounds, as well
as on rocks.
- It is possible to measure the height
of an elephant, by measuring the circumference of the front
foot. Twice the circumference, gives the approximate height.
- The upper ridge of the ear, starts
folding inwards, from the age of 10 and folds about an inch,
in 20 years. An elephant with a 1" fold on its ear, is
considered to be 30-35 years of age, approximately. There
are however, many exceptions to this rule.
- In the absence of a weigh bridge, the
following formulae can be applied, to weigh an elephant
- W = 12.8 (g+ng)-42811. W = 12.8 (g+ng)-4281
- W = Weight in Kg; g = girth (Chest
circumference just behind the forelimb, in cms); ng = neck
girth (in cms)
- W = l x g2 x 1.252. W = l x g2
- W = Weight in Pounds; l = length
(Anterior tip of the shoulder to point of tip, in inches); g
= girth (in inches)
- Elephants love spending lots of time
in the water and can swim long distances. They also love
wallowing in the marsh.
- Elephants travel extensively, walking
long distances in the wild, in search of food, shade,
minerals and water. Since they have an enormous food
requirement, they have to travel constantly to look for
fodder sources. They do not stay confined to a single place
for a long time which avoids habitat destruction.
- They walk at a slow pace of 4km/hr.
Elephant walk has been made into a music, (in the film
Hatari) which is popular all over the world.
- Elephants feed on all three tiers of
plant life i.e., lower (grass), middle (bush), and upper
- Elephants have very clean feeding
habits. While grazing, they pull out a bunch of grass and
dust the mud and dirt against their legs before eating it.
- Elephants drink 200-255 litres of
water a day. I.e., 50-60 litres at a time, 3-4 times a day.
A trunkful can retain 6-7 litres or even as much as 10
- Elephants can run short distances
quite quickly (25 Km/hr for short distances), or 30-40 kms/hr,
according to reports from Mudumalai Elephant Camp, in Tamil
Nadu. Even with hobbles they can hop very fast, but cannot
gallop like horses or run like cattle.
- Elephants can perceive sound
frequencies inaudible to the human ear. Frequencies below
the normal audible range are called infrasonic waves and
those above the normal audible range are called ultra sonic
waves. Examples of infrasonic waves are thunder, earthquakes
etc. Elephants sometimes communicate with each other through
infrasonic waves. This was discovered by Catherine Payne in
Africa. The region between the frontal projection and the
base of the trunk, produces vibrations. A simple experiment
to demonstrate this fact can be done, by submerging (half
way, to the middle of head) the elephant in water, facing
the current and tickling the frontal area. The vibrations
produced, can be seen as ripples, in the water. In an
African savannah, elephants can perceive thunder several
miles away and will move towards that direction to find the
rain. Elephants have several kinds of communications between
them. They are provided with large ears so that they can
receive as many of these frequencies, as possible.
- An elephant?s eye sight being very
poor, it relies very much on its sense of smell. Elephants
can recognise people by their sense of smell, even after
- In Kerala, there is a misconception
that, elephants fan their ears because they appreciate the
rhythm of the Panchavadyam, a musical symphony.
Although it makes a nice story, this is not true. Elephants
fan their ears, to cool their body. Sweating, in other
species such as man, helps maintain suitable body
temperature. Since elephants have few sweat glands, they
depend on their ears to regulate their body temperature. The
ear is an important organ in removing heat. The blood from
the various parts of the body is transported to the ear
where they are cooled due to its fanning motion. This cooled
blood, then flows back into the various parts of the body,
thus bringing down the body temperature. It is observed that
there is a difference of 1 degree centigrade in the
temperature, of arterial and venous blood of the ear.
- The normal body temperature of the
elephant is 96.6 OF,
( 36.9 OC)
- The skull has several sinuses and so
the head is not as heavy as it may appear.
- The elephant has only two pairs of
teeth, at a time and they are replaced 5 times during its
lifetime. The number of ridges on the teeth increase with
age . In most animals the teeth erupt from the bottom, but
in elephants, they grow and push from the back to the front.
The molars are replaced five times, in the lifetime of an
- The tusk is an outgrowth or extension
of the upper incisor or teeth. In males, it starts in two or
two and a half years and grows 3 - 4 inches every year. The
tusk has regenerative capacity. The pulp, which is conically
shaped, is present along the inside of the tusk. One has to
be careful not to damage the pulp, while trimming, or
shaping the tusk. Teeth in Sanskrit are called Dantam,
and thus the elephants are also called Danti. The
elephant uses its tusks in a variety of ways. Humans may be
right or left handed. Elephants also exhibit, a similar
dexterity, for a particular tusk. The tusks continue
growing, even after being cut.
- The Asian cow elephants have tushes,
but African cows have tusks.
- The tongue has restricted movement and
cannot be protruded out. The food can be hooked if placed on
the tongue and pushed back into the mouth.
- An elephant's trunk is formed by the
fusion of the upper lip and the nose. It is made of
approximately 1,00,000 muscles.
- There is no naso lacrimal duct,
running from the eye to the nose and so water runs out of
the eyes constantly.
- A few sweat glands are present on the
skin, found at the base of the nails. Since the sweat glands
are deficient, the elephant sucks secretions from the mouth
and sprays it on its body, with its trunk, to lower the body
- The skin is very thick and hence is
called a Pachyderm. The skin has several folds and wrinkles,
which help to remove heat. Though the skin is thick, the
elephant will experience pain when injured.
- Males and females have a temporal
gland, which produces secretions or temporal discharge .
Temporal gland activity in bulls, is characterised by
behavioural changes, particularly aggression, libido and
disobedience to words of commands. Some cow-elephants
occasionally exhibit temporal gland activity, but do not
show any pronounced behavioural changes.
- Elephants cannot jump up, because
their legs are not shaped correctly, for absorbing the shock
of a jump. They may leap horizontally however, as their knee
cap is placed very low, which helps them stand on or bend
their knees, like humans.
- The heart of an elephant does not have
a pointed apex, like other mammals. The ends are shaped
differently and have a bifid apex.
- As in marine mammals, the testes of a
male elephant are placed abdominally (close to the kidneys).
During musth, the testes enlarge in size (functional
- In a cow-elephant, the vulval openings
are between the hind legs. Clitoris is large and may be
15-30 cms long, but they mate like all other quadrupeds or
four legged animals.
- Elephants have two openings on the
roof of their mouth called vomero- nasal openings, which act
as scent glands. Mating consists of prolonged courting ,
short duration of penetration, several times a day. The
special position of the vulva makes the penis (when
erected), into a cobra shaped hood, to facilitate
penetration. An ejaculate may have 50-100ml of semen.
- The gestation period is 21 months.
Even when pregnant, ovulation takes place in cows.
- Calf at birth weighs 80-100 kg and
90-100 cms in height.
- Mammary glands are found between the
forelegs. They secrete milk through several pores. Usually
they suckle offspring for 4-5 years, but in captivity, the
calves are weaned after 2 years.
- Although herbivorous, the cholesterol
level in African elephants is high, compared to that of the
local tribes (Masai), who eat beef.
- There is no gall bladder in the
- Dog posture or 'sternal recumbency'
posture is a relatively safe and comfortable position in
other animals. In elephants this is dangerous, especially
when they are tired. The pleural cavity around the lungs is
absent in elephants, and they may die of suffocation if made
to sit in the dog posture for long periods under sedation,
or for any other purpose. Respiration rate is 10 PM (per
minute) while standing and 5 PM during recumbency.
- Like humans, elephants are also prone
to arthritis, because of the vertical position of their
- The total number of bones in the
elephant's body is 282 and the total number of vertebrae is
61. The bones are not very thick and so the likelihood of a
fracture is greater.
- Elephants can stand for long periods.
Horses and passerine birds have checked ligaments, which
help them to stand, while sleeping straight up. Similarly,
elephants are also provided with such feet, that can be
splayed, thus enabling them to stand for long periods. There
was an elephant in Thrippunithara, Kerala, that stood up for
18 months, when it was sick. Healthy elephants in captivity,
usually do not lie down during the day.
- Most animals, fold their hind limbs
backwards, while lying down, but elephants fold them
- Captive elephants in Kerala, are given
a restorative treatment during the monsoon, which is a
practise for human beings too, in Kerala.
- Elephants are efficient seed
dispersers. Seeds that pass out in the elephant's dung are
highly viable and germinate easily.
- They defecate 15-20 times a day. The
number of boli being 5-8 and weighing 1-21/2 kg. Elephants
urinate 10-15 times a day and a total quantity of 50-60
litres is expelled. Inadequate water intake produce
- Elephants can unerringly locate and
dig out water from the sub soil or river beds, during the
- Elephants have a remarkable memory for
events and people and are also believed to be emotional.
While in musth, captive male elephants deliberately try to
attack their mahouts.
- Elephants are gregarious by nature. In
the wild when a baby elephant is born, it is trained and
disciplined by every adult in the group. Captive born
calves, on the other hand, turn out to be truants, as they
are excessively pampered by humans. They turn out to be
problematic adults, if not trained properly after weaning.
- Elephants have matriarchal groups and
the leader of a herd is usually a cow-elephant. Males are
loosely attached to the herd. In summer, when there is
scarcity of food and water, the herds break up into smaller
herds and when favourable conditions return , they re-unite
to form a large herd with a larger number of individuals.
Elephants in the wild spend a minimum of 60-70% of their
activity in feeding. In summer during the day, the herds
spend 2-4 hours a day resting, to prevent heat strokes.
- Elephant herds when threatened, have
an interesting defence strategy. At first they all stand in
a line defending. Then they round up the young ones and
sub-adults into the centre and form a circle around them.
- Elephants can never be completely
domesticated. They always have a desire to return to the
wild, unlike some other domesticated species, such as dogs
and cats, which come back home.
- Elephants are a valuable commodity and
need to be handled with care and respect. In Artha
shastra, an ancient Indian text, Chanakya (the author),
described the value of elephants as equivalent to gold.
Chankaya says that, a man deserved capital punishment, if
charged of killing an elephant.
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SIGNIFICANCE OF VARIOUS INTERNAL AND EXTERNAL ORGANS
Dr. K.C. Panicker
Trunk: The trunk is the most attractive feature in
an elephant and makes it look different from other herbivores.
Trunk is an extension of the upper lip. The shape and length
of the trunk varies in various elephants. Some elephants have
a very long trunk that touches the ground, where as others
have very short trunks. The free end of the trunk is produced
into a triangular finger like, tip. This organ enables the
elephant to pick up the smallest of objects from the ground.
The trunk is made of two types of muscles. It is by the action
of these muscles that the elephant is able to extend or
retract its trunk. The trunk has two openings on its free end.
The opening within the trunk forms the nasal passage. The nasa
passage runs into the centre of the forhead bump, followed by
the gullet and finally branches into the lungs.
The elephant thus breathes and also sucks water, through
the trunk. The trunk is also used for other things such as
spraying the body with water, uprooting grass, pulling down
branches, tearing the palm branches apart etc. The elephant
has a highly developed sense of smell. Using the trunk, they
can smell objects and people. Bulls use the trunk to check if
a cow is in heat. They hold twigs or branches by the trunk to
scratch their body.
Tusks: Tusks are modified incisors of the upper jaw.
They arise form the front portion of the skull.1/3rd of the
tusk is embedded in the skull and the rest is visible from
outside. 2/3rds of the tusk is hollow and consists of pulp.
Tusks continue to grow throughout the elephant’s life. In
captivity, the tusks are trimmed once in every two years.
Elephants with long divergent tusks are considered attractive
in Kerala. Tusks acquire various shapes. They are also called
"white gold", because of the demand for ivory. Ivory continues
to be a priced commodity, for which several elephants have
been killed. It is therefore rightly said that the tusk is the
elephant's enemy. The tusk is used a defence weapon during
fights between elephants. They are also used to push trees
down, lift objects etc. The Asian cow elephant and Makhnas
posses tushes instead of tusks. African bulls and cows posses
Ears: Broad and fan shaped ears make an elephant
attractive. An elephant that fans its ears constantly is
considered healthy. The ears help balance the body temperature
of the elephant. The skin on the ear is very thin and the
veins can be seen very clearly. Injections and intravenous are
administered through the veins on the ears. The sides of the
ears begin folding inwards as the elephant becomes older. It
is possible to make a rough estimate of the elephant’s age by
looking at the folds. The ear folds about an inch in 30 years,
meaning if an elephant has a fold measuring an inch, its age
can be predicated as 30 years.
Eyes: The eyes are relatively small in size. The
elephant cannot see objects at long distance. The colour of
the eyes are normally honey or dark brown. A third eyelid
within the eye protects the pupil. This makes it difficult to
apply ointments on the eye. Hence medicines must be applied
from the lower portion of the eye.
Teeth: The elephant possesses only molars and there
are four of them at any given time. The upper surface of the
teeth are made up of several ridges. The teeth are replaced
constantly. New teeth arise from behind the mouth and push
forwards while growing and the older teeth to fall off. The
teeth are replaced six times in an elephant's lifetime. Thus
there are a total of 24 teeth. Occasionally one may observe a
single worn out tooth or a pair, on one side of the jaw. If a
pair are seen then one of them is the remnant of the old tooth
and the other is the rudiment of the new tooth. The teeth are
replaced at various ages in an elephant's life time. The first
set of teeth appear when the elephant is a year old. These are
replaced when the elephant is six years of age. This is
followed by further replacements at 9, 25, 50 and 100 years of
age. The age of an elephant can be estimated by observing its
teeth. The sixth set is the largest of all the sets and it
measures 1 feet in length, 2 inches in breadth and
approximately weigh four kilo grams.
Fore and hind limbs: The limbs are strong and pillar
like in appearance. In
Malayalam, the forelimbs are called nada and
hindlimbs, amaram. The joints between the bones are
vertical which make it difficult for elephants to jump
forwards. The limbs bear digits and nails. The digits are not
visible as they are embedded within the skin. The nails are
visible. Most elephants have 18 nails, 5 on each foreleg and 4
on each hindleg. The number of nails varies in number and some
posses 16 or 17 nails. Those with 16 nails are considered
inauspicious. It is rare to see elephants with 20 nails, which
is considered as a very auspicious sign.
Tongue: The tongues is fleshy and cannot be
protruded outwards. While feeding a depression is found in the
middle of the tongue where the food material is placed and
folded backwards into the mouth.
Digestive system: Stomach is single chambered. The
intestine is approximately 170 feet long. Digestion takes
place in the large intestine.
Liver: Liver is large but gall bladder is absent.
Heart: has 2 apexes. The rate of heartbeat is 28
times per minute, but it is greater when lying down ie 35
times per minute. Heart beat is recorded from the veins behind
Testis : are located internally, on either side of
the vertebral column.
Temporal glands : are located in the temporal region
of the brain. They lead to a temporal opening which is located
between the eye and the ear. During musth, the temporal gland
becomes enlarged and secretes a fluid, which runs out through
the temporal opening.
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EVOLUTIONARY HISTORY AND SUB SPECIES
Dr. K.C. Panicker
Evolutionary history of elephants dates back several
million years, along the geological time scale. They underwent
a series of changes over the years to evolve into the present
form. They are placed under the family Proboscidae. A few
ancestors of elephants are mentioned below.
Moeritherium : The fossils of Moeritherium were
first discovered near Lake Moeris in Egypt, hence the name.
Moeritherium is considered to be the ancestor of all
Proboscides. This species was about 2 feet tall and looked
more like a pig than an elephant. The eyes and ears were small
and the trunk was absent. The evidence for its ancestry to
elephants is in the skull structure and dentition. The upper
jaw bears outgrowths of incisor teeth.
Dinotherium : This group is nicknamed as monsters
because of their appearance. On the lower jaw a pair of
backward curving tusks were present. They had a flat head and
the trunk was quite long.
Trilophodon : Trilophodon received its name from the
peculiar dentition it exhibited. The upper region of the first
two molars were fused to form a crown. This group also were
characterised by an extended lower jaw bearing two long tusks.
Platybilodon : They had short trunks and a large
mouth. Each jaw bore a pair of tusks. The tusks of the lower
jaw were short and spoon-shaped.
Mastodon : Mastodons were about the same size as
modern elephant but of a much bigger build. Its head showed
features such as a flattened forehead rising to a prominent
domed crown, large curved tusks in the upper jaw and a well
developed trunk. The body was covered with hair.
Mammoth : The mammoth is the most popular among
ancestors of elephants. Their fossil remains have been found
preserved in the icy ground of Siberia. Mammoths were
extremely tall (measuring up to 15 feet) and possessed a pair
of large curved tusks emerging from the upper jaw. Their body
was covered with long, thick hairs as protection against the
cold. Scientists claim that the present two elephant types --
Asian and African -- evolved directly from mammoths.
There are several differences between the two living
Smaller in size
Larger in size
Shorter in height
Taller in height
Highest point at the middle of the
Highest point at shoulder
Comparatively smaller ears
Long and large trunk
Comparatively smaller trunk
One finger like process at the tip of
Two finger like processes at tip of
Tusks only in males
Tusks in both sexes
Commonly found to posses 18 nails
14 nails are common
Back is unbroken and convex in
dip on the back between fore and hind
Bull-dog faced with twin domed
Elongate,narrow face with flat
Musth episodes usually in male
Musth in both sexes
Easier to domesticate
Comparatively difficult to
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Sub Species of Asian elephants (Elephas
The Asian elephants (Elephas maximus) are classified
into 7 sub species, based on their geographical distribution.
How ever scientific data for this classification is not
Name of sub species
1. Elephas maximus ceylonicus
2. Elephas maximus indicus
3. Elephas maximus bengalensis
4. Elephas maximus dakamensis
5. Elephas maximus burmanicus
6. Elephas maximus hirsutus
7. Elephas maximus sumatranus
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Sub Species of African
elephants (Loxodonta africana ) :s
Loxodonta africana africana
Loxodonta africana cyclotis