The Asian or Asiatic elephant (Elephas maximus) is the only living species of the genus Elephas and is distributed in Southeast Asia from India in the west to Borneo in the east. Three subspecies are recognized — Elephas maximus maximus from Sri Lanka, the Indian elephant or E. m. indicus from mainland Asia, and E. m. sumatranus from the island of Sumatra. Asian elephants are the largest living land animals in Asia.
Since 1986, E. maximus has been listed as endangered by IUCN as the population has declined by at least 50% over the last three generations, estimated to be 60–75 years. The species is pre-eminently threatened by habitat loss, degradation and fragmentation. In 2003, the wild population was estimated at between 41,410 and 52,345 individuals. Female captive elephants have lived beyond 60 years when kept in seminatural situations, such as forest camps. In zoos, elephants die at a much younger age and are declining due to a low birth and high death rate.
The genus Elephas originated in Sub-Saharan Africa during the Pliocene ranging throughout Africa into southern Asia. The earliest indications of domestication of Asian elephants are engravings on seals of the Indus Valley civilization dated as third millennium BC.
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.
As is common with large animals, the dimensions of the Asian elephant are often exaggerated, on average, the shoulder height of males rarely exceeds 2.7 m (9 ft) and that of the females, 2.4 m (8 ft). Average height of females is 2.24 m (7.3 ft), and average weight 2.72 t (3.00 short tons) rarely exceeding 4.16 t (4.59 short tons). Large bulls weigh up to 5.4 t (6.0 short tons) and are 3.2 m (10 ft) at the shoulder. 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 8 tonnes (8.8 short tons), stood 3.35 m (11 ft) tall at the shoulders 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).
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 longitudinals 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 offense.
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, 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 serve to dig for water, salt, and rocks, to debark trees, as levers for maneuvering fallen trees and branches, for work, for display, for marking trees, as weapon for offense and defense, as trunk-rests, as protection for the trunk. They 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. Furthermore, the forehead has two hemispherical bulges, unlike the flat front of the African elephant. Unlike African elephants which rarely use their forefeet for anything other than digging or scraping soil, Asian elephants are more agile at using their feet in conjunction with the trunk for manipulating objects. They can sometimes be known for their violent behavior.
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 1041⁄2 lb (47 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 color is usually gray, and may be masked by soil because of dusting and wallowing. Their wrinkled skin is movable and contains many nerve centers. It is smoother than 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 to 91 °F). Body temperature averages 35.9 °C (96.6 °F).
Asian elephants are highly intelligent and self-aware. They have a very large and highly convoluted neocortex, a trait also shared by humans, apes and certain dolphin species. Asian elephants have the greatest volume of cerebral cortex available for cognitive processing of all existing land animals. Elephants have a volume of cerebral cortex available for cognitive processing that exceeds that of any primate species, and extensive studies place elephants in the category of great apes in terms of cognitive abilities for tool use and tool making. Elephants are reported to go to safer ground during natural disasters like tsunamis and earthquakes, although there have been no scientific records of this.
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 (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.
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.