Habitat evaluation and population viability analysis of the last population of cao vit gibbon (Nomascus nasutus): Implications for conservation

The cao vit gibbon (Nomascus nasutus) is among the most endangered primates in the world. The only surviving population lives in a karst forest patch along the China-Vietnam border. In this study, we used high-resolution satellite images to evaluate the habitat quality of the gibbon in the area immediately surrounding the last population and predict the potential gibbon habitat. We then used Vortex to simulate population responses to changes in the habitat's carrying capacity. Our results showed the gibbon population is approaching the carrying capacity of their current habitat, and carrying capacity has a significant impact on population changes. Two potential habitats were located in a forest connected to the current habitat by a narrow forest corridor, situated above an underground river. Based on the results, we recommend: (1) prohibiting agriculture and grazing activities within the current gibbon habitat; (2) expanding the Cao Vit Gibbon Conservation Area in order to protect potential cao vit habitats in Vietnam; (3) protecting forest corridor that connect the current cao vit habitat to potential habitats; and (4) rehabilitating the forests currently depauperate of important food species in order to support the expansion of both the gibbon population and the range. This research both provides important insight into sustaining the current gibbon population as well as suggestions for both Vietnamese and Chinese local governments planning habitat restoration at the study site.