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Orangutan conservation in Sarawak

90% of Sarawak's orangutans are found in the protected area complex of Batang Ai National Park and Lanjak Entimau Wildlife Sanctuary (map). Together with the Betung Kerihun (Bentuang-Karimun) Nature Reserve across the border in Kalimantan, they form the largest protected area where the Bornean species of orangutan occur. The orangutans here are recognised as the northwest Bornean sub-species, Pongo pygmaeus pygmaeus.

Several short-term surveys of orangutans have been done in Sarawak, by George Schaller⁽¹⁾ in 1961, Mike Meredith⁽²⁾ in 1993, Raleigh Blouch⁽³⁾ in 2000, and Gurmaya and Silang⁽⁴⁾ in 2002. Based on these surveys, the estimate for orangutans in Sarawak is about 1,300.

Threats

The Bornean orangutans are currently restricted to remote and less accessible areas but, even there, their population is threatened with extinction. The reasons for the decline include illegal hunting, habitat loss and lack of enforcement of the legislation that protects the species. These threats are very severe and have led to predictions that by 2020, less than 10% of Borneo's total orangutan population will survive.

On-going WCS Projects

• Nest count surveys commenced in Batang Ai NP in July 2003 and in Lanjak Entimau WS in March 2005. The main objective of the research was to collect nest data to estimate abundance and distribution of orangutans, and assess threats to these animals throughout the habitat complex.
   
• Tree phenology surveys were carried out to identify structure and composition of trees along the transects. This information is useful to find the fruit trees used by orangutans to forage and whether they prefer to build nests on common trees or otherwise.
   
• Conservation education is a vital part of the orangutan project. WCS with partners including the Sarawak Forestry Corporation (SFC) engage local communities and schools to raise awareness and to develop a sense of ownership among them. This is carried out with the hope that there will be a change in the current "tragedy-of-the-commons" mentality in the next generation. More...

Future Directions

• Improved research methods in estimating densities of the species will be tested. These include retrospective methods to estimate nest decay rate, and reduce survey efforts by manipulating decay time during analysis, occupancy survey methods to estimate relative abundance, and DNA studies using hair and faecal samples in capture-recapture protocol.
   
• Other conservation efforts include increasing conservation education activities with local communities and other major stakeholders, and working with travel agencies to encourage conservation ethics with regard to habitat and species protection.

References:

1 Schaller, G.B. (1961). The orang-utan in Sarawak. Zoologica 46: 73-82.

2 Meredith, M. (1993). Draft Management Plan for Batang Ai National Park, 1993-1995. Wildlife Conservation Society, Kuching, Sarawak.

3 Blouch, R.A. (2000). Primates. In Soepadmo, E. & Chai, P (Eds.). Development of Lanjak Entimau Wildlife Sanctuary as Totally Protected Area: Scientific Report (pp 150-159). ITTO, Yokohama.

4 Gurmaya, K.K. & Silang, S. (2002). Development of Lanjak Entimau Wildlife Sanctuary as a Totally Protected Area. Phase III. A Study of habitat conditions, populations, and distribution of orang utan in Lanjak Entimau Wildlife Sanctuary and Batang Ai National Park, Sarawak, Malaysia. ITTO, Kuching.