Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat

Abstract

Despite the spread of human-impacted wildlife habitats, few studies have examined how animals adapt their socioecology in agricultural-forest ecotones. Anthropogenic processes such as agricultural development directly affect the ecological challenges that species face. In agricultural-forest ecotones cultivated foods that are palatable, energy-rich, easily digestible, and that often occur as large, clumped and spatially abundant orchards or fields may offer foraging advantages over natural foods. However, crop raiding can be risky: harassment, injury or even death may arise from confrontations with people. The factors that affect grouping decisions and activity budgets within anthropogenic environments are unknown. Twelve months of focal data were collected from direct observations of one chimpanzee community inhabiting a forest-farm mosaic at Bossou, Guinea. Wild fruit abundance did not directly influence daily party size. Instead, cultivated resource consumption, in combination with other social factors, provided chimpanzees with an alternative to fissioning. Chimpanzee party size did not differ between crop raids and wild feeds, but party cohesiveness did increase during raids. Furthermore, males and females adapted their activity budgets in different ways to integrate cultivated resources into their broader ecological strategy. As species are increasingly forced into anthropogenically impacted habitats, models of fission-fusion dynamics and other socioecological adaptations need to take into account exploitation of cultivated, energy-rich crops.