Seasonal Differences in Activity Patterns of Geoffroyís Spider Monkeys (Ateles geoffroyi) Living in Continuous and Fragmented Forests in Southern Mexico

Understanding how primates adjust their behavior in response to seasonality in both continuous and fragmented forests is a fundamental challenge for primatologists and conservation biologists. During a 15-mo period, we studied the activity patterns of 6 communities of spider monkeys (Ateles geoffroyi) living in continuous and fragmented forests in the Lacandona rain forest, Mexico. We tested the effects of forest type (continuous and fragmented), season (dry and rainy), and their interaction on spider monkey activity patterns. Overall, monkeys spent more time feeding and less time traveling in fragments than in continuous forest. A more leafy diet and the spatial limitations in fragments likely explain these results. Time spent feeding was greater in the rainy than in the dry season, whereas time spent resting followed the opposite pattern. The increase in percent leaves consumed, and higher temperatures during the dry season, may contribute to the observed increase in resting time because monkeys probably need to reduce energy expenditure. Forest type and seasonality did not interact with activity patterns, indicating that the effect of seasonality on activities was similar across all sites. Our findings confirm that spider monkeys are able to adjust their activity patterns to deal with food scarcity in forest fragments and during the dry season. However, further studies are necessary to assess if these shifts are adequate to ensure their health, fitness, and long-term persistence in fragmented habitats.