Predator avoidance and food patch proximity influence sleeping site use of Assamese macaques in a limestone forest of Southwest Guangxi, China

Objectives We investigated the sleeping site use of one group of Assamese macaques in Southwest Guangxi, China. We examined their behavioral adaptation to limestone forests by evaluating hypotheses of predator avoidance, food proximity, and range or resource defense. Materials and Methods We recorded the locations of sleeping sites on a topographic map using a grid cell method and mapped the use of foraging patches within the home range. Results Assamese macaques used 19 different sleeping sites, mainly located on cliffs. They rapidly entered sleeping sites and then remained silent. They preferred three sites but never used them for more than four consecutive nights. Sleeping site use was positively correlated with the number of surrounding foraging patches, but the distances between sleeping sites and the last/first feeding areas (84.16 +/- 41.26 and 94.88 +/- 45.83 m, respectively) were not affected by seasonal fluctuations in fruit availability; these distances were longer than those predicted under a multiple central place foraging (MCPF) strategy but shorter than those predicted under a central place foraging (CPF) strategy. The observed distances between the sleeping sites and the first feeding areas in the rainy season were similar to the predicted distances of an MCPF strategy. The macaques slept in peripheral parts of their home range as expected, and there were no conflicts with neighboring groups. Discussion Sleeping site use was strongly affected by predator avoidance and proximity to food resources, but not by resource defense. The vertical distribution of sleeping sites on hills was not influenced by fruit availability. The macaques are closer to using an MCPF strategy to maximize food harvest efficiency, particularly in the rainy season. Assamese macaques' sleeping site use in limestone forests supports the hypotheses of predator avoidance and food proximity.