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.

普通黑猩猩（Pan troglodytes）是现存与现代人类亲缘关系最近的物种，常被用作模式生物，助力学界探索史前人类的行为模式与生态环境。尽管最初学界曾认为黑猩猩为草食性动物，但现有观测显示它们会捕猎24种鸟类、有蹄类动物、啮齿类、猴类及其他灵长类，并会运用从工具使用到群体协作等多样捕猎策略。本研究整合13项已发表的黑猩猩捕猎行为与食性相关文献，旨在明确黑猩猩的猎物偏好性。我们提取了两类变量数据：一类为猎物特异性变量，包括目标猎物物种、其体重以及其在猎物群落中的相对丰度；另一类为捕猎者特异性变量，涵盖捕猎方式、黑猩猩群体规模与性比。本研究将上述变量纳入广义线性模型（generalized linear model），以探究影响黑猩猩猎物偏好的关键驱动因素。我们针对乌干达2处观测点与坦桑尼亚2处观测点中被捕获的各猎物物种，计算了雅各布指数（Jacobs' Index）值。黑猩猩偏好体重不超过7.6±0.4千克的猎物，对应物种包括幼年薮羚（Tragelaphus scriptus）与黑白疣猴（Colobus guereza）。黑猩猩群体的性比似乎会影响其猎物偏好：当群体由雄性主导时，黑猩猩对猎物的偏好性会显著增强。黑猩猩捕猎偏好相关研究数据，既可通过明确需重点管护的猎物物种，为野生动物保护管理项目提供支撑，也有助于深化学界对人类捕猎行为演化历程的认知。