MODELING THE DISTRIBUTION OF THE SOUTHERN YELLOW-CHEEKED GIBBON (NOMASCUS GABRIELLAE) USING MAXENT

Abstract

The Southern yellow-cheeked gibbon (Nomascus gabriellae) is an endangered species found only in a small region of Indochina, and its populations have declined in most known sites. In this study, we use Maxent, a robust and widely used species distribution modeling approach, to predict the current and future distributions of the Southern yellow-cheeked gibbon over its entire range based on an extensive review of published records. Overall, we compile and provide a comprehensive set of known distribution records of the species from Viet Nam and Cambodia. The model results show that N. gabriellae is likely to occur in many areas around the Central Highlands in both Viet Nam and Cambodia and the southern end of Laos. Our study suggests that protected areas in this region will play a key role in conserving the gibbons. In addition, the distribution of the gibbon under future climate conditions, even in the best case scenario, is likely to shrink significantly, as the species would have to move to higher altitudes. Under such an impact, the populations would become more fragmented and restricted to a few areas of higher elevation. Our study also confirms that the climatic difference across its distribution range may not be entirely responsible for the speciation and biogeography of the N. annamensis/gabriellae complex.