The Asian or Asiatic elephant (Elephas maximus) is the only living species of the genus Elephas and is distributed in Southeast Asia from India and Nepal in the west to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, the 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, 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 generations, estimated to be 60–75 years. The Asian elephant is primarily threatened by loss of habitat, habitat degradation, fragmentation and poaching. 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 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 emigrating into southern Asia. The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley civilization dated to the third millennium BC.
Carl Linnaeus first described the genus Elephas and an elephant from Ceylon under the binomial Elephas maximus in 1758. In 1798, Georges Cuvier first described the Indian elephant under the binomial Elephas indicus. In 1847, Coenraad Jacob Temminck first described the Sumatran elephant under the binomial Elephas sumatranus. Frederick Nutter Chasen classified all three as subspecies of the Asian elephant in 1940.
Three subspecies are currently recognised: the Sri Lankan elephant, the Indian elephant, and the Sumatran elephant. In 1950, Paules Edward Pieris Deraniyagala described the Borneo elephant under the trinomial Elephas maximus borneensis, taking as his type an illustration in National Geographic, but not a living elephant in accordance with the rules of the International Code of Zoological Nomenclature. E. m. borneensis lives in northern Borneo and is smaller than all the other subspecies, but with larger ears, a longer tail, and straight tusks. Results of genetic analysis indicate that its ancestors separated from the mainland population about 300,000 years ago.