Anatomy and Genetics

Elephants are truly fascinating animals, besides the obvious trunk and big ears, they have a number of other specialised parts of their bodies that are incredibly interesting!

• Elephants belong to the family Proboscidae.
• Their closest relative is the hyrax a small rodent-like animal from Africa
• Asian elephants are of five strains and they are Indian, Burmese, Ceylonese, Sumatran and Malaysian.
• An Asian cow elephant weighs 2.5 - 3.5 tonnes and a bull weighs 3.5 to 5 tonnes.
• Size of the neck is not proportionate to that of the head and so elephants have short necks to balance their huge head.
• 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 weighbridge, the following formulae can be applied, to weigh an elephant: A simple way of weighing an elephant is given by the following formula: Body Weight = (18.0 x girth cm ) – 3,336
• 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 ultrasonic 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 is poorer than other senses, it relies very much on its sense of smell. Elephants can recognise people by their sense of smell, even after several years.
• 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 Asian elephant.
• 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.
• An elephant's trunk is formed by the fusion of the upper lip and the nose. Trunk = 6 muscles broken down to 150 bundles of muscle fibers
• 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.
• There is no nasolacrimal 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 temperature.
• 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.
• 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 hypertrophy).
• 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.
• 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 elephant.
• 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 limbs.
• 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.