The Asian elephant (Elephas maximus), also known as the Asiatic elephant, is the only living species of the genus Elephas and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, E. m. indicus from mainland Asia and E. m. sumatranus from the island of Sumatra.
The Asian elephant is the largest living land animal in Asia. Since 1986, the Asian elephant has been listed as Endangered on the IUCN Red List, as the population has declined by at least 50 percent over the last three elephant generations, which is about 60–75 years. It is primarily threatened by loss of habitat, habitat degradation, fragmentation and poaching. In 2019, the wild population was estimated at 48,323-51,680 individuals.
Female captive elephants have lived beyond 60 years when kept in semi-natural surroundings, such as forest camps. In zoos, Asian elephants die at a much younger age; captive populations are declining due to a low birth and high death rate.
The genus Elephas originated in Sub-Saharan Africa during the Pliocene and spread throughout Africa before expanding into the southern half of Asia. The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley Civilisation dated to the 3rd millennium BC.
Taxonomy
Carl Linnaeus proposed the scientific name Elephas maximus in 1758 for an elephant from Ceylon. Elephas indicus was proposed by Georges Cuvier in 1798, who described an elephant from India. Coenraad Jacob Temminck named an elephant from Sumatra Elephas sumatranus in 1847 Frederick Nutter Chasen classified all three as subspecies of the Asian elephant in 1940. These three subspecies are currently recognised as valid taxa. Results of phylogeographic and morphological analyses indicate that the Sri Lankan and Indian elephants are not distinct enough to warrant classification as separate subspecies.
Elephas maximus borneensis was proposed by Paules Edward Pieris Deraniyagala in 1950 who described an elephant in an illustration published in the National Geographic magazine, but not a living elephant in accordance with the rules of the International Code of Zoological Nomenclature. The Asian elephants living in northern Borneo are smaller than all the other subspecies, but with larger ears, a longer tail, and straight tusks. Results of genetic analysis indicate that their ancestors separated from the mainland population about 300,000 years ago.
The following Asian elephants were proposed as extinct subspecies, but are now considered synonymous with the Indian elephant:
- Syrian elephant (E. m. asurus), proposed by Deraniyagala in 1950, was based on Bronze Age illustrations.
- Chinese elephant (E. m. rubridens), also proposed by Deraniyagala in 1950, was based on a bronze statuette of an elephant.
- Javan elephant (E. m. sondaicus), also proposed by Deraniyagala in 1950, was an illustration of a carving on the Buddhist monument of Borobudur.
Characteristics
In general, the Asian elephant is smaller than the African bush 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. The forehead has two hemispherical bulges, unlike the flat front of the African elephant.
Size
On average, when fully-grown, males are about 2.75 m (9.0 ft) tall at the shoulder and 4 t (4.4 short tons) in weight, while females are smaller at about 2.40 m (7.9 ft) at the shoulder and 2.7 t (3.0 short tons) in weight.
Sexual dimorphism in body size is relatively less pronounced in Asian elephants than in African bush elephants; with males averaging 15% and 23% taller in the former and latter respectively.
Length of body and head including trunk is 5.5–6.5 m (18–21 ft) with the tail being 1.2–1.5 m (3.9–4.9 ft) long.
The largest bull elephant ever recorded was shot by the Maharajah of Susang in the Garo Hills of Assam, India in 1924. It weighed an estimated 7 t (7.7 short tons), stood 3.43 m (11.3 ft) tall at the shoulder and was 8.06 m (26.4 ft) long from head to tail.
There are reports of larger individuals as tall as 3.7 m (12 ft).
Trunk
The distinctive trunk is an elongation of the nose and upper lip combined; the nostrils are at its tip, which has a one finger-like process. The trunk contains as many as 60,000 muscles, which consist of longitudinal and radiating sets.
The longitudinal are mostly superficial and subdivided into anterior, lateral, and posterior. The deeper muscles are best seen as numerous distinct fasciculi in a cross-section of the trunk. The trunk is a multipurpose prehensile organ and highly sensitive, innervated by the maxillary division of the trigeminal nerve and by the facial nerve.
The acute sense of smell uses both the trunk and Jacobson’s organ. Elephants use their trunks for breathing, watering, feeding, touching, dusting, sound production and communication, washing, pinching, grasping, defense and offence.
The “proboscis” or trunk consists wholly of muscular and membranous tissue, and is a tapering muscular structure of nearly circular cross-section extending proximally from attachment at the anterior nasal orifice, and ending distally in a tip or finger.
The length may vary from 1.5 to 2 m (59 to 79 in) or longer depending on the species and age. Four basic muscle masses—the radial, the longitudinal and two oblique layers—and the size and attachments points of the tendon masses allow the shortening, extension, bending, and twisting movements accounting for the ability to hold, and manipulate loads of up to 300 kg (660 lb).
Muscular and tendinous ability combined with nervous control allows extraordinary strength and agility movements of the trunk, such as sucking and spraying of water or dust and directed air flow blowing.
The trunk can hold about four litres of water. Elephants will playfully wrestle with each other using their trunks, but generally use their trunks only for gesturing when fighting.
Tusks
Tusks serve to dig for water, salt, and rocks, to debark and uproot trees, as levers for maneuvering fallen trees and branches, for work, for display, for marking trees, as weapon for offence and defence, as trunk-rests, and as protection for the trunk. Elephants are known to be right or left tusked.
Female Asian elephants usually lack tusks; if tusks—in that case called “tushes”—are present, they are barely visible, and only seen when the mouth is open.
The enamel plates of the molars are greater in number and closer together in Asian elephants. Some males may also lack tusks; these individuals are called “filsy makhnas”, and are especially common among the Sri Lankan elephant population.
A record tusk described by George P. Sanderson measured 5 ft (1.5 m) along the curve, with a girth of 16 in (41 cm) at the point of emergence from the jaw, the weight being 104 1⁄2 lb (47.4 kg).
This was from an elephant killed by Sir Brooke and measured 8 ft (2.4 m) in length, and nearly 17 in (43 cm) in circumference, and weighed 90 lb (41 kg).
The tusk’s weight was, however, exceeded by the weight of a shorter tusk of about 6 ft (1.8 m) in length which weighed 100 lb (45 kg).
Skin
Skin colour is usually grey, and may be masked by soil because of dusting and wallowing. Their wrinkled skin is movable and contains many nerve centres.
It is smoother than that of African elephants, and may be depigmented on the trunk, ears, or neck. The epidermis and dermis of the body average 18 mm (0.71 in) thick; skin on the dorsum is 30 mm (1.2 in) thick providing protection against bites, bumps, and adverse weather.
Its folds increase surface area for heat dissipation. They can tolerate cold better than excessive heat. Skin temperature varies from 24 to 32.9 °C (75.2 to 91.2 °F). Body temperature averages 35.9 °C (96.6 °F).
Intelligence
Asian elephants have a very large and highly developed neocortex, a trait also shared by humans, apes and certain dolphin species. They have a greater volume of cerebral cortex available for cognitive processing than all other existing land animals.
Results of studies indicate that Asian elephants have cognitive abilities for tool use and tool-making similar to great apes.
They exhibit a wide variety of behaviours, including those associated with grief, learning, allomothering, mimicry, play, altruism, use of tools, compassion, cooperation, self-awareness, memory, and language.
Elephants reportedly head to safer ground during natural disasters like tsunamis and earthquakes, but data from two satellite-collared Sri Lankan elephants indicates this is untrue.
Distribution and 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 occur from sea level to over 3,000 m (9,800 ft). In the eastern Himalaya in northeast India, they regularly move up above 3,000 m (9,800 ft) in summer at a few sites.
In China, the Asian elephant survives only in the prefectures of Xishuangbanna, Simao, and Lincang of southern Yunnan.
In Bangladesh, some isolated populations survive in the south east Chittagong Hills.
A herd of 20–25 wild elephants was reported as being present in the Garo Hills of Mymensingh in the late-1990s, being detached from a big herd in the Peack hills of India and prevented from returning by fences put up in the meantime by the Indian border security force. The herd was estimated at about 60 individuals in 2014.
Three subspecies are recognised: the Sri Lankan elephant occurs in Sri Lanka;
- the Indian elephant occurs in mainland Asia: Bangladesh, Bhutan, Cambodia, China, India, Laos, Malay Peninsula, Myanmar, Nepal, Thailand, Vietnam;
- the Sumatran elephant occurs in Sumatra.
Conservation
It is a quintessential flagship species, deployed to catalyze a range of conservation goals, including habitat conservation at landscape scales, generating public awareness on conservation issues, and mobilisation as a popular cultural icon both in India and the West.
The World Elephant Day is celebrated on 12 August since 2012. Events are organized to divulge information and to engage people about the problems that the Asian elephant is facing.August has been established as the Asian Elephant Awareness Month by zoos and conservation partners in the United States.
In China, Asian elephants are under first-level protection. Yunnan province has 11 national and regional nature reserves. In total, the covered protected area in China is about 510,000 km2 (200,000 sq mi). In 2020, the population of Asian elephants in Yunnan was estimated at around 300 individuals.
As conflicts between humans and wild elephants have emerged around protected areas in the last years, the prefecture of Xishuangbanna built food bases and planted bananas and bamboo to create a better habitat.
In Thailand, Salakpra Wildlife Sanctuary and Than Thanlod National Park are protected areas hosting around 250-300 elephants, according to figures from 2013. In recent years the National Park has faced issues due to encroachment and over-exploitation.
In India, the National Board of Wildlife did a recommendation, allowing coal mining in the Dehing Patkai elephant reserve in April 2020. The decision raised concerns between students and environmental activists who launched an online campaign to stop the project.
In captivity
About half of the global zoo elephant population is kept in European zoos, where they have about half the median life span of conspecifics in protected populations in range countries.
This discrepancy is clearest in Asian elephants: infant mortality is twice that seen in Burmese timber camps, and adult survivorship in zoos has not improved significantly in recent years. One risk factor for Asian zoo elephants is being moved between institutions, with early removal from the mother tending to have additional adverse effects.
Another risk factor is being born into a zoo rather than being imported from the wild, with poor adult survivorship in zoo-born Asians apparently being conferred prenatally or in early infancy. Likely causes for compromised survivorship is stress and/or obesity.
Foot problems are commonly observed in captives elephants. These are related to lack of exercise, long hours standing on hard substrates, and contamination resulting from standing in their dung. Many of the problems are treatable. However, mistreatment may lead to serious disability or death.
Demographic analysis of captive Asian elephants in North America indicates that the population is not self-sustaining. First year mortality is nearly 30 per cent, and fecundity is extremely low throughout the prime reproductive years.
Data from North American and European regional studbooks from 1962 to 2006 were analysed for deviation of the birth and juvenile death sex ratio. Of 349 captive calves born, 142 died prematurely.
They died within one month of birth, major causes being stillbirth and infanticide by either the calf’s mother or by one of the exhibition mates. The sex ratio of stillbirths in Europe was found to have a tendency for excess of males.