Spider Monkeys (Ateles geoffroyi yucatenensis) Cope with the Negative Consequences of Hurricanes Through Changes in Diet, Activity Budget, and Fission–Fusion Dynamics

Abstract

Hurricanes can bring about dramatic changes to ecosystems and adversely affect animals that live in them. We monitored behavioral responses in wild spider monkeys (Ateles geoffroyi yucatanensis) in the aftermath of two hurricanes (Emily and Wilma) that moved through the Yucatan peninsula in 2005. We predicted that the monkeys would shift their diets depending on relative food availability and experience a change in the distribution of activity patterns. Because spider monkeys’ social organization is characterized by a high degree of fission–fusion dynamics, we predicted they would form smaller subgroups subsequent to the hurricanes to mitigate competition over limited food resources. We compared their responses in the immediate aftermath of Hurricane Emily and across the dry seasons before and after both hurricanes, to control for seasonal changes, by examining their activity budgets, foods consumed, and subgrouping dynamics. In the immediate aftermath of Hurricane Emily spider monkeys spent less time moving and more time feeding on leaves than before the hurricane and they were in smaller subgroups. In the dry season after both hurricanes the monkeys spent more time resting and less time moving than before the hurricanes, and leaves replaced fruit as their primary food resource. They fused into larger subgroups less often and had smaller subgroup sizes in the dry season after than before the hurricanes. Thus, the high degree of fission–fusion dynamics of spider monkeys was instrumental in affording the behavioral flexibility critical to cope with the negative post-hurricane consequences.