Asian elephant

Appearance

In general, the Asian elephant is smaller than the African elephant and has the highest body point on the head. The back is convex or level. The ears are small with dorsal borders folded laterally. It has up to 20 pairs of ribs and 34 caudal vertebrae. The feet have more nail-like structures than those of African elephants — five on each forefoot, and four on each hind foot.

Distribution

Asian elephants inhabit grasslands, tropical evergreen forests, semi-evergreen forests, moist deciduous forests, dry deciduous forests and dry thorn forests, in addition to cultivated and secondary forests and scrublands. Over this range of habitat types elephants are seen from sea level to over 3,000 m. In the Eastern Himalaya in northeast India, they regularly move up above 3,000 m in summer at a few sites.

Three subspecies are recognized:
⤷  the Sri Lankan elephant lives in Sri Lanka;
⤷  the Indian elephant lives in mainland Asia: India, Nepal, Bangladesh, Bhutan, Myanmar, Thailand, Malay Peninsular, Vietnam, Cambodia, Laos, and China;
⤷  the Sumatran elephant lives in Sumatra and Borneo.

In China, Asian elephants survive only in the prefectures of Xishuangbanna, Simao, and Lincang of southern Yunnan. In Bangladesh, only isolated populations survive in the Chittagong Hills.

In 2003, Mitochondrial DNA analysis and microsatellite data indicated that the Borneo elephant population is derived from stock that originated in the region of the Sunda Islands. The genetic divergence of Borneo elephants warrants their recognition as a separate Evolutionary Significant Unit.

Status

"Elephas maximus" is listed on CITES Appendix I.

Asian elephants are quintessential flagship species, deployed to catalyze a range of conservation goals, including:
⤷ habitat conservation at landscape scales
⤷ generating public awareness of conservation issues
⤷ mobilization as a popular cultural icon both in India and the West

Behavior

Elephants are crepuscular. They are classified as megaherbivores and consume up to 150 kg of plant matter per day. They are generalist feeders, and both grazers and browsers, and were recorded to feed on 112 different plant species, most commonly of the order Malvales, and the legume, palm, sedge and true grass families. They browse more in the dry season with bark constituting a major part of their diet in the cool part of that season. They drink at least once a day and are never far from a permanent source of fresh water. They need 80–200 litres of water a day and use even more for bathing. At times, they scrape the soil for clay or minerals.

Adult females and calves may move about together as groups, but adult males disperse from their mothers upon reaching adolescence. Bull elephants may be solitary or form temporary 'bachelor groups'.

Cow-calf unit sizes generally tend to be small, typically consisting of three adult females which are most likely related, and their offspring; however, larger groups containing as many as 15 adult females may occur. There can also be seasonal aggregations containing 100 individuals at a time, including calves and subadults. Until recently, Asian elephants, like African elephants, were thought to typically follow the leadership of older adult females, or matriarchs, but females can form extensive and very fluid social networks, with individual variation in the degree of gregariousness. Social ties generally tend to be weaker than in African elephants.

Elephants are able to distinguish low amplitude sounds. They use infrasound to communicate; this was first noted by the Indian naturalist Krishnan and later studied by Payne.

Tiger predation on Asian elephants is rare and restricted to small calves.

Habitat

Asian elephants inhabit grasslands, tropical evergreen forests, semi-evergreen forests, moist deciduous forests, dry deciduous forests and dry thorn forests, in addition to cultivated and secondary forests and scrublands. Over this range of habitat types elephants are seen from sea level to over 3,000 m. In the Eastern Himalaya in northeast India, they regularly move up above 3,000 m in summer at a few sites.

Three subspecies are recognized:
⤷  the Sri Lankan elephant lives in Sri Lanka;
⤷  the Indian elephant lives in mainland Asia: India, Nepal, Bangladesh, Bhutan, Myanmar, Thailand, Malay Peninsular, Vietnam, Cambodia, Laos, and China;
⤷  the Sumatran elephant lives in Sumatra and Borneo.

In China, Asian elephants survive only in the prefectures of Xishuangbanna, Simao, and Lincang of southern Yunnan. In Bangladesh, only isolated populations survive in the Chittagong Hills.

In 2003, Mitochondrial DNA analysis and microsatellite data indicated that the Borneo elephant population is derived from stock that originated in the region of the Sunda Islands. The genetic divergence of Borneo elephants warrants their recognition as a separate Evolutionary Significant Unit.Elephants are crepuscular. They are classified as megaherbivores and consume up to 150 kg of plant matter per day. They are generalist feeders, and both grazers and browsers, and were recorded to feed on 112 different plant species, most commonly of the order Malvales, and the legume, palm, sedge and true grass families. They browse more in the dry season with bark constituting a major part of their diet in the cool part of that season. They drink at least once a day and are never far from a permanent source of fresh water. They need 80–200 litres of water a day and use even more for bathing. At times, they scrape the soil for clay or minerals.

Adult females and calves may move about together as groups, but adult males disperse from their mothers upon reaching adolescence. Bull elephants may be solitary or form temporary 'bachelor groups'.

Cow-calf unit sizes generally tend to be small, typically consisting of three adult females which are most likely related, and their offspring; however, larger groups containing as many as 15 adult females may occur. There can also be seasonal aggregations containing 100 individuals at a time, including calves and subadults. Until recently, Asian elephants, like African elephants, were thought to typically follow the leadership of older adult females, or matriarchs, but females can form extensive and very fluid social networks, with individual variation in the degree of gregariousness. Social ties generally tend to be weaker than in African elephants.

Elephants are able to distinguish low amplitude sounds. They use infrasound to communicate; this was first noted by the Indian naturalist Krishnan and later studied by Payne.

Tiger predation on Asian elephants is rare and restricted to small calves.

Reproduction

Bulls will fight one another to get access to estrous females. Strong fights over access to females are extremely rare. Bulls reach sexual maturity around the age of 12–15. Between the age of 10 and 20 years, bulls undergo an annual phenomenon known as "musth". This is a period where the testosterone level is up to 100 times greater than nonmusth periods, and they become extremely aggressive. Secretions containing pheromones occur during this period, from the paired temporal glands located on the head between the lateral edge of the eye and the base of the ear.

The gestation period is 18–22 months, and the female gives birth to one calf, only occasionally twins. The calf is fully developed by the 19th month, but stays in the womb to grow so that it can reach its mother to feed. At birth, the calf weighs about 100 kg, and is suckled for up to three years. Once a female gives birth, she usually does not breed again until the first calf is weaned, resulting in a 4– to 5-year birth interval. Females stay on with the herd, but mature males are chased away.

Elephants' life expectancy has been exaggerated in the past; they live on average for 60 years in the wild and 80 in captivity.

Females produce sex pheromones; a principal component thereof, -7-dodecen-1-yl acetate, has also been found to be a sex pheromone in numerous species of insects.

Predators

The pre-eminent threats to Asian elephants today are loss, degradation and fragmentation of habitat, leading in turn to increasing conflicts between humans and elephants. They are poached for ivory and a variety of other products including meat and leather.

Cultural

Further information: Elephants in Kerala culture and Cultural depictions of elephants

The elephant plays an important part in the culture of the subcontinent and beyond, featuring prominently in Jataka tales and the "Panchatantra". They play a major role in Hinduism: the god Ganesha's head is that of an elephant, and the "blessings" of a temple elephant are highly valued. Elephants have been used in processions in Kerala, where the animals are adorned with festive outfits.

The elephant is depicted in several Indian manuscripts and treatises. Notable amongst these is the "Matanga Lila" of Rameswara Pandita and the "Hastividyarnava" of Sukumar Barkaith. The latter manuscript is from Assam in northeast India.