A definitive subspecific classification as Elephas maximus borneensis awaits a detailed range-wide morphometric and genetic study.

[8] The range of wild elephants in Sabah and Kalimantan seems to have expanded very little in the past 100 years despite access to suitable habitat elsewhere on Borneo.

Borneo's soil tends to be young, leached, and infertile, and there is speculation that the distribution of wild elephants on the island may be limited by the occurrence of natural mineral sources.

The elephant density and population size varied throughout the five key ranges affected by (i) conversion of lowland forest, (ii) fragmentation of habitat, and (iii) existing land use activities such as logging.

[8] In the 19th century, a zoological exploration established that wild elephants occurred naturally in a restricted region of northeastern Borneo.

In 1940, Frederick Nutter Chasen considered Bornean elephants as descendants of an introduced stock, and placed them in the subspecies Elephas maximus indicus.

Reginald Innes Pocock having studied specimens in the British Museum of Natural History disagreed in 1943, and placed all Sundaic elephants in the subspecies Elephas maximus sumatrensis.

In 1950, Paules Edward Pieris Deraniyagala described a subspecies Elephas maximus borneensis, taking as his type an illustration in the National Geographical Magazine.

[18] In 2003, mitochondrial DNA analysis and microsatellite data indicated that the extant population is derived from Sundaic stock, but has undergone independent local evolution for some 300,000 years since a postulated Pleistocene colonization, and possibly became isolated from other Asian elephant populations when land bridges that linked Borneo with the other Sunda Islands and the Asian mainland disappeared after the Last Glacial Maximum 18,000 years ago.

When in 1521 the remnants of Ferdinand Magellan's circumnavigation of the Earth reached Brunei, the chronicler of the voyage recounted that the delegation from the flagship Victoria was conveyed to and from the ruler's palace on elephants caparisoned in silk.

This custom had been discontinued by the time later visitors arrived in Brunei in the 1770s, who reported wild-living elephant herds that were hunted by local people after harvest.

[2] The arrival of elephants in the northern Kalimantan region of Borneo coincides with the rule of the Sultans of Sulu over Sabah.

When this lease was signed, most of these timid and largely domesticated small elephants under the employ of Sulu's shipbuilders and traders were released into the forests so they could live deep inside the jungle away from any feuding sultan who might use them for war.

This single act of releasing the pachyderms to the wild made the Bolkiah family of Sulu and their allies the savior of what remaining elephants are left, old locals attest.