The roots of human hunting and meat eating lie deep in our evolutionary past shared with chimpanzees (Pan troglodytes). From the few habituated wild populations, we know that there is considerable variation in the extent to which chimpanzees consume meat. Expanding our knowledge of meat eating frequencies to more, yet unhabituated, populations requires noninvasive, indirect quantitative techniques. We here evaluate the use of stable isotopes to reconstruct meat-eating behavior in wild chimpanzees. We present hair isotope data (n = 260) of two western chimpanzee (P. troglodytes verus) groups from Taï forest (Côte d’Ivoire) and relate them to directly observed amounts of meat consumed, sex/female reproductive state, and group, while controlling for differences between individuals, seasons, and observation efforts. Succeeding seven months of hunting observations, we collected hair of 25 individuals for sequential analysis of δ¹⁵N and δ¹³C. Hunting success in the 7-month study period varied between the groups, with 25 successful hunts in the East group and only 8 in the North group. However, our models only found a direct relationship between amounts of meat consumed and variation within individual hair δ¹⁵N values in the East group, but not in the North group and not when comparing between individuals or groups. Although on average East group individuals consumed more than double the amount of meat than North group individuals, their δ¹⁵N values were significantly lower, suggesting that differences in microhabitat are substantial between group territories. The effect of sex/female reproductive state was significant in δ¹⁵N and δ¹³C, suggesting it related to access to food or feeding preferences. We conclude that several factors additional to diet are influencing and thus obscuring the isotope ratios in wild chimpanzee hair, particularly when comparing between sexes and social groups.

人类狩猎和吃肉的根源在我们与黑猩猩（Pan troglodytes）共同进化的过去中很深。从少数几个习惯化的野生种群中，我们知道黑猩猩食用肉类的程度存在很大差异。将我们的肉食频率知识扩展到更多但尚未有人居住的人群，需要无创，间接的定量技术。我们在这里评估使用稳定同位素重建野生黑猩猩的食肉行为。我们提供 了两个西部黑猩猩（P. troglodytes verus）的头发同位素数据（n = 260））（科特迪瓦）泰伊森林的群体，并将其与直接观察到的肉食量，性别/女性生殖状态和群体联系起来，同时控制个体，季节和观察力之间的差异。随后的狩猎观察七个月，我们收集了25名个人为δ序列分析的头发¹⁵ N和δ ¹³在7个月的研究期间，两组之间变化C.狩猎成功，与25个东方集团，成功猎杀8只在北组。然而，我们的模型才发现肉量之间的直接关系，消费和个人的头发内的变化δ ¹⁵N值在东方组中，但不在北方组中，并且在个人或组之间进行比较时也没有。虽然平均东方集团个人消费的肉类比北组人的两倍以上的量，其δ ¹⁵的N值均显著降低，表明微生差异组领土之间巨大的。的性别/女性生殖状态的影响是在δ显著¹⁵ N和δ ¹³ C，这表明它与获得食品或喂养偏好。我们得出的结论是，除了饮食之外，还有几个因素会影响并掩盖野生黑猩猩头发中的同位素比率，尤其是在性别和社会群体之间进行比较时。