Predicting suitable habitat for the endangered Javan Gibbon in a submontane forest in Indonesia

Abstract

Species distribution modeling is an essential tool for understanding the ecology of species and has many applications in conservation. Using maximum entropy (MaxEnt) modeling, we identify the key factors shaping the potential distribution of the endangered Javan Gibbons Hylobates moloch in one of the main remnant habitats, Gunung Halimun Salak National Park (GHSNP), Indonesia, using presence-only data collected between October and November 2015, and in April and May 2016. Maxent results showed that forest canopy density and annual temperature were the principal variables predicting the distribution of Javan Gibbons, with contribution scores of 53.9% and 35.6%, respectively. The predictive distribution map indicated that suitable habitat for Javan Gibbons is not uniformly distributed within GHSNP, i.e., suitable habitat is not located evenly throughout the region, with some areas more suitable than others. Highly suitable habitat comprises the largest proportion of habitat, with 42.1% of GHSNP classified as highly suitable habitat, whereas 24.7% was moderately suitable, and 33.2% of habitat was of low suitability for Javan Gibbons. Priority should be given to increasing habitat quality in degraded areas and law enforcement patrols to reduce degradation in peripheral regions of the park as part of the conservation management strategy.