Asian primates in fragments: Understanding causes and consequences of fragmentation, and predicting primate population viability.

Ongoing efforts to conserve the Asian primates are severely challenged by increasing rates of habitat loss and fragmentation. Underlying drivers such as rapid economic and population growth throughout much of South, East, and Southeast Asia have confined several populations of Asian primates to isolated fragments. Conservation efforts for these primates are partly hampered by a poor understanding of fragmentation, resulting in an inability to draw up effective long-term conservation responses. In this manuscript, I show that fragmentation can be understood better when treated both as stress and a threat. Moreover, despite a myriad of causes of fragmentation reported, most are broad descriptions or subject to various interpretations. Here I describe the use of the IUCN-CMP Unified Classifications of Direct Threats Version 3.2, a convenient and universal tool, for more precise identification of the causes and consequences of fragmentation for Asian primates. I further describe the interrelated variables influencing the persistence of Asian primates in fragments, and the conditions affecting these variables.