Abstract
Chimpanzees Pan troglodytes are the closest extant relative of modern
humans, and are often used as a model organism to help understand
prehistoric human behavior and ecology. Originally presumed herbivorous,
chimpanzees have been observed hunting 24 species of birds, ungulates,
rodents, monkeys, and other primates, using an array of techniques from
tools to group cooperation. Using the literature on chimpanzee hunting
behavior and diet from 13 studies, we aimed to determine the prey
preferences of chimpanzees. We extracted data on prey-specific variables
such as targeted species, their body weight, and their abundance within
the prey community, and hunter-specific variables such as hunting
method, and chimpanzee group size and sex ratio. We used these in a
generalized linear model to determine what factors drive chimpanzee prey
preference. We calculated a Jacobs’ Index value for each prey species
killed at two sites in Uganda and two sites in Tanzania. Chimpanzees
prefer prey with a body weight of 7.6 ± 0.4 kg or less, which
corresponds to animals such as juvenile bushbuck Tragelaphus scriptus
and guereza colobus monkeys Colobus guereza. Sex ratio in chimpanzee
groups appears to drive chimpanzee prey preference, where chimpanzees
increasingly prefer prey when in male-dominated groups. Prey preference
information from chimpanzee research can assist conservation management
programs by identifying key prey species to manage, as well as
contribute to a better understanding of the evolution of human hunting
behavior.