Elephant Statistics

Asian Elephant (Elephas maximus)
The elephant is the largest terrestrial animal that evolved nearly 60 million years ago.

Family: Elephantidae
Order: Proboscidea
Status: Endangered (EN A1cd)

Subspecies
Elephas maximus maximus (Sri Lankan elephant)
Elephas maximus indicus (Asian Mainland elephant)
Elephas maximus sumatranus (Sumatran elephant)

Elephants in Borneo, on the basis of their genetic distinctiveness and evolutionary history, may constitute a separate subspecies, Elephas maximus borneensis according to DNA analysis carried out by Fernando et al., (2003).

Range and distribution
 

Elephant Population Tables

Minimum and maximum estimates of Asian Elephant numbers in the wild

Regional estimates of Asian Elephant numbers in the wild in India (Project Elephant Synchronized Census, 2002)

Number of elephants in captivity in India (Project Elephant, December 2000)

Elephant population trend in India between 1980 and 2002 (Project Elephant, 2002) 

Elephant Reserves in India (Project Elephant, August 2004)

Asian and African elephants – the difference

Elephant Anatomy and Physiology

Bones | Trunk | Teeth | Tusks | Brain | Ear | Eyes | Skin | Musth | Body Surface | Digestion & Defecation | Communication

Elephant Nutrition

Nutrition | Water | Protein | Fibre | Fat | Minerals | Vitamins

Range and distribution                                                                                                                   Top

The Asian elephants were distributed over a large area extending from the Tigris-Euphrates basin, eastward through the Indian sub-continent and Southeast Asia to north of the Yangtze river in China. An estimated 44,000 wild Asian elephants are presently distributed in thirteen Asian countries, viz., India, Nepal, Bhutan, Bangladesh, Sri Lanka, Myanmar, Thailand, Laos, Cambodia, Vietnam, China (only southern Yunnan), Malaysia (peninsular Malaysia and Sabah) and Indonesia (Sumatra and Kalimantan). There are about 16,000 elephants in captivity, found mostly in Myanmar, Thailand and India.
 

Asian and African elephants – the difference                                                                                Top

• Although both Asian and African elephants have five toes on each foot, they differ in the number of nails present on the toes. Asian elephants generally have 5 nails in the forefoot and 4 on the hind.

• The Asian elephant has only one finger at the trunk tip compared to two in the African.

• African elephants have roughly half moon shaped plates/lamellae, where as in the Asian, the ridges are transverse and parallel.

• In Asian elephants, females do not have tusks unlike their African counterparts.

• African elephants compared to their Asian counterparts have larger tusks.

Bones                                                                                                                                            Top

• The whole skeleton of the elephant weighs about 16.5% of its total body weight.

• An adult female Asian elephant is reported to have 282 bones (Shoshani et al. 1982).

• Weighing on an average 52 kilos, the head, which looks dimensionally massive, is not as heavy as it appears because of the large number of sinuses present. It is made up of 51 bones, all aerated by sinuses (Van-der-Merve et al. 1995).

• The vertebral column is made of 61 bones and the longest rib may reach 96.5 cm in length.

• The cervical bone is very short in the elephant. This is why an elephant cannot turn its neck and look backwards and this makes the elephant nervous about anything approaching from behind.

• The almost vertical limbs enable them to stand for long periods of time, as well as support the enormous body weight. The bones are arranged in direct line with one another, like a pillar providing rigid support for the enormous body. But the vertical nature of the foot does not allow the elephants to jump, but they can hop and leap. They can also walk forward and backward on very narrow stretches of land.

•  The thigh bone is the largest bone in the body. An adult animal has a 114.3-cm long femur (thigh bone).

Trunk                                                                                                                                            Top

• Trunk is the modified upper lip.

• It is used to drink, dress the food as well as used as a snorkel. The trunk also grasps the food and conveys it to the mouth for mastication. Since the tongue cannot be protruded, the dextrous trunk places the food on the tongue.

• The trunk also acts as an olfactory organ, which is a well-developed means of communication in elephants. It is used to test different smells by touching the object and placing the tip inside the mouth.

• The trunk is also used in threatening gestures and play fighting. During mock charges, it stretches its trunk outward, but if it holds its trunk tucked down, it is a real charge.

• With the trunk, an elephant-calf can lift about 4.5% of its bodyweight while an adult elephant can lift around 270 kg.

Digestion and defecation                                                                                                             Top

• The elephant is a non-ruminant mega herbivore and its digestive system is compared to that of a horse or a zebra.

• Elephants while grazing, pull out grass from the ground, remove the dust and mud by beating on the forelimb, and then eat the dressed food. They spend considerable time dressing palm fronds. The animal eats only the inner portion.

• Healthy elephants thoroughly masticate edible portions of the food.

• The maximum capacity of the stomach in an adult female elephant was found to be 76.6 litres (Shoshani 1982). In herbivores many of the complex carbohydrates that cannot be digested by the mammalian enzymes are digested by fermentation with the help of symbiotic microbes present in the anterior or posterior portions of the gastrointestinal tract. Anaerobic microbes inhabit the caecum and colon of elephants, similar to those seen in the rumen and reticulum of ruminants. The highly specialised anaerobic bacteria act on fragmented particles of cellulose, chromatophores and other partially degraded substances digesting these plant materials. Volatile fatty acids (VFA) is a major source of energy for elephants as in other herbivores, but the proportion of propionic acid is less. Probably this is compensated by absorption of carbohydrates from the foregut. Hence, the proportion of soluble carbohydrates available for fermentation in the caecum is much less than that of rumen in cattle.

• On an average, elephants excreted 3.9-kg faeces per 100 kg of body mass a day. Elephants defecate 14-18 times in a day passing 5-6 boluses of 1-1.5 kg, each time.

• Elephants void urine 10-14 times a day. Volume discharged at one time varies from 5-11 litres with a total 24-hour discharge of about 50 litres (Benedict Sikes 71, Wallach Boever 83).

• Elephants use the digestive strategy of passing large amounts of low quality forage through their gut within a short period of time (Loehlein et al. 2001). The passage time of food materials through the gastrointestinal tract ranges from 18 to 24 hours.

Teeth                                                                                                                                           Top

• Elephants have six sets of molars in their lifetime.

• A total of four teeth are present at a time, two in the lower and upper jaw respectively.

• If two teeth are seen at a time in the same alveolar pocket, the anterior one is the worn out old tooth and the posterior is the new tooth. This movement of teeth is unique to elephants, as in other animals the milk teeth are shed when the permanent teeth erupt.

• The last (sixth) set of teeth appears at the age of around 40 years and is almost worn out by the age of 60. Old elephants with their worn out tooth often confine themselves to an area where succulent food to the tune of 200-250 kg and water to an extent of 125-150 litres are available daily, until their probable death due to starvation. Hence in the wild, elephants that feed exclusively on fibrous food, the longevity is almost limited to 60 plus.

• In captivity, when high calorie, easily digestible, soft foods are given, elephants may live up to 70 years or even more.

Tusks                                                                                                                                          Top

• Tusks are lateral incisors that grow continuously throughout the animal’s lifetime. They emerge on the sides of the base of the trunk. Almost half of the tusk from its base is hollow with tusk pulp inside. It is made up of dentine and the surface is covered with shiny white enamel. The tusks are used for digging, carrying loads, debarking trees, in combat as well as in behavioural display.

• Asian elephant females do not have tusks but have a very small growth known as tushes, which are usually harder than the tusks.

• Some male Asian elephants also do not have tusks and are known as makhnas.

• External appearance of tusks varies with almost all elephants.

• They grow at an average of 15-20 cm in length each year.

Brain                                                                                                                                            Top

Elephants posses the largest brain among land mammals (Cozzi et al. 2001), four times the size of a human brain.
 

Ear                                                                                                                                               Top

• The elephant ear is very large and peculiar in shape.

• Ears are used for auditory purposes, balancing the body, thermoregulation and for signaling.

• Elephants have difficulty in losing excess body heat through the skin surface. An elephant’s ear will shed almost 100% of the total heat when maximally vasodilated and flapped gently.

• Since the size and shape of the ear is different in different elephants it is used in identification.

• Whenever an elephant perceives threat, it opens its ears wide.

• The fold on the dorsal aspect of the ear is an indication of the age of elephant.

• Elephants cannot hear above 10.5 kHz at an intensity level of 60 dB, but can hear low frequency sounds.

• Elephants communicate by producing deep growling or rumbling noises. When alarmed they let out an ear splitting trumpet.

Body surface                                                                                                                               Top

• Irregular surface of the elephant’s body cools it better than a smooth surface as the irregular surface retains more water.

• Elephants take dust-baths even after spending a great deal of time in the water. Apart from cooling the body, dust baths protect the elephants from insects and radiation (Rees 2002).

Eyes                                                                                                                                             Top

• Eyes in elephants are 1.5-2 inches long and 1 inch wide.

• The area of vision is limited to only up to 30-50 metres because of the position of the eyeball, presence of trunk and ear as well as the short neck. When the elephant senses trouble, it moves its body alternatively from side to side in order to see behind, instead of walking straight ahead. But this is compensated by extremely well developed olfactory and auditory capacities.

Skin                                                                                                                                             Top

• Pachyderm, derived from the Greek word Pachydermose (thick skinned).

• The skin of an elephant is as thick as 2.5-4 cm on the head and back.

• The colour of the skin is greyish black.

• De-pigmentation is noticed on the fore head, upper portion of the trunk and the ears.

• Although the skin is dry due to the absence of sweat gland, it is soft and supple.

• The highly wrinkled skin helps absorb water and helps retain surface moisture to compensate for evaporative heat loss. This is highly useful during periods of drought.

Communication                                                                                                                           Top

• Chemical communication relates to signalling between opposite sexes for mating. Secretions at the base of the toes, temporal gland and urogenital tract as well as saliva and mucus lining of the trunk produce chemical signals. Olfactory communication is achieved by pheromones. Urine of a cow elephant in oestrus produce pheromones to attract bulls, while the strong smell of the temporal gland secretion advertises musth in bulls.

• Tactile communication happens through sight and touch. When elephants meet, they vocalise, rub their bodies, press each other’s foreheads, intertwine trunks or put trunks in each other's mouths. These tactile contacts reinforce their bonds.

• Acoustic communication happens both in the audible and inaudible (subsonic) range. Extensive studies have confirmed that elephants produce low frequency sounds to interact in thick vegetation and among separated groups. In nature, infrasonic sounds are produced by ocean waves, volcanoes, earthquakes, thunderstorms, whales, etc. Elephants are the first terrestrial mammals reported to produce infrasound. The intensity of sounds produced is strongest at 18 hertz compared to 100 Hz in humans and 2500 Hz in mice. Infrasonic calls produced by elephants can travel 1-5 km or even more.

• Seismic waves in the ground are also used for communication.

Musth                                                                                                                                          Top

• The word musth is derived from the hindi or persian word ‘mast’ meaning intoxicated or angry.

• It is a physiological phenomenon seen in all adult healthy male elephants, usually every year, when the elephant shows aggressive behaviour and secretion is seen from the swollen temporal gland.

• Some of the other signs seen during this time is unusual alertness, spreading of ears, staring eyes with roving eyeballs, stiff and tense body, extended blowing of trunk and unusual vocalisation.

• Musth bulls are extremely dominant and try to keep the non-musth males away from the females.

• In many cases, successful mating in the wild happens in a bull in musth or one that is about to enter the musth period.

• The duration of musth may vary between 3-80 days.

Nutrition                                                                                                                                      Top

• The lateral movement of the jaws are not pronounced during mastication in elephants. This along with the lesser volume of the buccal cavity leads to poor digestibility and hence continuous feeding in wild elephants.

• Elephants graze and browse on the most tender and palatable portions of different plants and trees.

• Elephants spend between 12-18 hours feeding each day. They spend lesser time in savannah woodland and deciduous forest, compared to rainforest, due to the abundance of perennial grasses.

• The elephant feeds on leaves, bark, stem, twigs, pith, root, fruits and flowers.

• The number of plant species consumed generally exceeds 50 species in dry habitats, more than 100 in deciduous forests and over 200 in rainforest.

• Family Graminae (grasses including bamboo), Cyperaceae (sedges), Palmae (palms), Leguminosae (legumes), Combertaceae (Combertum family), Euphorbiaceae (spurges), Moraceae (figs), Anacardiaceae (Cashew family), Rhamnaceae (buckthorns) and the order Malvales contribute to the bulk of the elephant’s diet.

• Grasses and legumes are more important in drier habitats, while palms, vines and a variety of fruits are commonly consumed in moist forests.

Water                                                                                                                                          Top

Apart from pure metabolic requirements, elephants need water for their natural functions like spraying on the body as well as for wallowing, for body temperature regulation since the elephant hardly sweats. It is estimated that an average sized adult Asian elephant loses 40 litres of water through urine and 20 litres through the lungs and skin. On an average elephants require a minimum of 150-200 litres of water each day
 

Protein                                                                                                                                        Top

Proteins are polypeptides of amino acids required for building of body tissues. Several amino acids are not synthesised by mammals on their own and have to be supplied in the diet as essential amino acids. Among herbivores, only ruminants can synthesise several amino acids with the help of symbiotic microbes in the rumen. However, elephant being a non-ruminant herbivore, both qualitative and quantitative presence of protein in the diet is important in its nutrition.

Studies on Asian elephants in the wild in southern India showed the browse intake during the wet season had a crude protein content of 13-20%. During the dry season the crude protein was 6-18%. Grasses showed correspondingly lower value values of crude protein both during the wet and dry seasons.
 

Fibre                                                                                                                                           Top

Elephants digest crude fibre with the help of microbes present in the hind gut, as is the case in other non-ruminant herbivores like horses. The elephant’s digestive system and teeth are adapted to a diet high in fibre content. The elephant being a continuous feeder with its large digestive tract, takes feeds low in energy but high in bulk. Both browse and grass are rich in fibre.
 

Fat                                                                                                                                              Top

The natural diet of elephants is low in fat, found to be 1.2-1.8 % of the dry matter intake.
 

Minerals                                                                                                                                     Top

Not much is known about the requirements for various minerals and vitamins in elephants. The tendency of wild elephants to feed on the bark of certain trees suggested that this might be a source for some minerals. Estimate of Ca requirement for Asian elephants is put at 60 g per day (Sukumar 1989). Ca concentration is generally high in legumes and low in grasses, while both P and Na are low in both legumes and grasses. At least 8-9 g of calcium is required for the proper growth of the tusks (Mc Cullagh 1969).

The deficiency of certain minerals in the elephants leads to Reproductive problems, Poor growth, Emaciation and Listlessness, Affects growth, reproduction and lactation, leads to Abnormal growth, poor appetite, Zn abnormality, Anaemia, emaciation, pale mucus membrane and irregular pulse.
 

Vitamins                                                                                                       

Vitamins are a group of organic compounds essential for normal maintenance, growth and reproductive functions apart from protein, fat, carbohydrates and minerals. Many herbivores synthesise most, if not all their requirement of B complex vitamins.

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