The Bornean orangutan (Pongo pygmaeus) declined by over 50% between 1999 and 2015 — from approximately 104,000 to fewer than 70,000 individuals. Deforestation and palm oil expansion are primary drivers. Individual welfare impacts of forest loss include: starvation as food trees are cleared; acute trauma from forest clearance equipment; orphaning when mothers are killed (baby orangutans are sometimes captured for illegal pet trade); and behavioral stress from range compression.
Wildlife rescue organizations including Borneo Orangutan Survival (BOS) Foundation operate the world's largest orangutan rescue and rehabilitation program, caring for hundreds of individuals. Rehabilitation is welfare-intensive, requiring years of forest skill training before release. BOS and IUCN work on forest protection and rescue operations across Kalimantan and Sabah.
The Bornean pygmy elephant (Elephas maximus borneensis) is a distinct subspecies found only in northeastern Borneo. Estimated 1,500-2,000 individuals survive in increasingly fragmented lowland forest. Welfare threats include: habitat loss from palm oil plantation expansion, poisoning by farmers whose crops are damaged, electrocution from uninsulated power lines near forest edges, and stress from range compression. Sabah Wildlife Department conducts translocation operations for conflict elephants.
Proboscis monkeys (Nasalis larvatus) — unique to Borneo — require intact mangrove and riverine forest; deforestation has severely reduced populations. Sun bears (Helarctos malayanus) — the world's smallest bear — are threatened by deforestation and capture for bile farming and pet trade. The Bornean Sun Bear Conservation Centre in Sabah rehabilitates former pet and bile bears with welfare-attentive care.
Palm oil deforestation remains the single greatest wildlife welfare driver in Borneo. The Roundtable on Sustainable Palm Oil (RSPO) certification aims to prevent further deforestation; however, certification coverage and effectiveness are contested. Consumer campaigns targeting brands using non-certified palm oil have had some success, but deforestation continues. Wildlife welfare improvements require both certified sustainable palm oil and enforcement of forest protection laws.