The sub-species Pongo pygmaeus pygmaeus is listed as the most severely threatened orangutan worldwide with a total of between 3,000-4,500 animals, of which 2,000 live in Sarawak in Batang Ai National Park and Lanjak-Entimau Wildlife Sanctuary. 

The orangutans were found in an area of about 14,000 hectares (140 sq km) in Ulu Sungai Menyang, close to Batang Ai National Park. Local Iban communities had been aware of the existence of orangutans in this area, but until recently no major research had been conducted in Ulu Sungai Menyang.

Melvin Gumal, Director of Wildlife Conservation Society, Malaysia Program, said: “It is indeed wonderful to hear the Government’s initiative towards protecting these orangutan and their habitat especially when preliminary scientific data indicates the existence of a globally significant population.”

Field surveys were conducted in February by staff from the Sarawak Forest Department, assisted by Sarawak Forestry Corporation, Wildlife Conservation Society and Borneo Adventure. The surveys covered 248 kilometers (154 miles) of transects in the hilly, undulating terrain in central Borneo. Ground surveys were supplemented by data from aerial surveys so that 80 percent of the study area was covered.

A total of 995 nests were found in the area. Fresh nests were found in all transects as well as in the remote areas covered by the aerial surveys indicating recent use of the area by these rare orangutans. 

Upon confirmation that the area had a globally significant population of the rare sub-species, the Government of Sarawak officially indicated the need to protect this area in perpetuity. It is already a High Conservation Value Forest, considered to have an area of high biological, cultural, economic and livelihood significance.

The Sarawak Government intends to hold a dialogue with local communities and the other key stakeholders to discuss options and to involve them in any conservation effort in the area.

The four organizations involved in the survey will conduct a follow-up study in the area to formulate strategic actions involving all stakeholders including the local communities. 

WCS orangutan conservation work in the Batang Ai – Lanjak Entimau landscape is supported by the U.S. Fish and Wildlife Service’s Great Apes Conservation Fund.