The Sumatran elephant was once widespread on the island, and Riau Province was believed to have the largest elephant population in Sumatra with over 1,600 individuals in the 1980s.[1] In 1985, an island-wide rapid survey suggested that between 2,800 and 4,800 elephants lived in all eight mainland provinces of Sumatra in 44 populations. Twelve of these populations occurred in Lampung Province, where only three populations were extant in 2002 according to surveys carried out between September 2000 and March 2002. The population in Bukit Barisan Selatan National Park was estimated at 498 individuals, while the population in Way Kambas National Park was estimated at 180 individuals. The third population in Gunung Rindingan–Way Waya complex was considered to be too small to be viable over the long-term.
By 2008, elephants had become locally extinct in 23 of the 43 ranges identified in Sumatra in 1985, indicating a very significant decline of the Sumatran elephant population up to that time. By 2008, the elephant was locally extinct in West Sumatra Province and at risk of being lost from North Sumatra Province too. In Riau Province only about 350 elephants survived across nine separate ranges.
As of 2007, the population of Sumatran elephants is estimated to be 2,400–2,800 wild individuals, excluding elephants in camps, in 25 fragmented populations across the island. More than 85% of their habitat is outside of protected areas.
In Aceh, radio-collared Sumatran elephant clans preferred areas in dense natural forests in river and mountain valleys at elevation below 200 m (660 ft); from there, they moved into heterogenous forests and foraged near human settlements mainly by night.