Abstract:
The common chimpanzee Pan troglodytes is the closest extant relative of modern
humans and is 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, 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 data 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 adult ashy red colobus monkeys
(Piliocolobus tephrosceles). Sex ratio in chimpanzee groups is a main driver in developing
these preferences, where chimpanzees increasingly prefer prey when in proportionally
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.
