Prey preference of the chimpanzee Pan troglodytes

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.