Density of a Reintroduced Population of Bornean Orangutans (Pongo pygmaeus) in Pristine and Disturbed Forest Areas, Sungai Wain Protection Forest, East Kalimantan, Indonesia

Sungai Wain Protection Forest is among the final extant primary lowland coastal forests remaining in East Kalimantan (Fredriksson and Nijman, 2004). From 1992-1997 82 formerly captive Bornean orangutans (Pongo pygmaeus) were released in Sungai Wain Protection Forest through the Wanariset Orangutan Reintroduction Project (Russon and Susilo, 1999). Forest fires burned approximately 60% of the reserve in 1998 (Fredriksson and Nijman, 2004). An extensive nest census conducted in 1998 produced an estimate of 13-17 orangutans remaining in Sungai Wain Protection Forest (Russon and Susilo, 1999). Very little research has been conducted on this reintroduced population of orangutans since the 1998 nest survey. In this study, a new nest survey will be conducted in order to produce a current estimate of orangutan densities in Sungai Wain Protection Forest. Orangutan density estimates in the primary forest area will be compared to densities in areas of forest which have been disturbed by fires