Lowe Adriana E, Hobaiter Catherine, Asiimwe Caroline, Zuberbühler Klaus, Newton-Fisher Nicholas E
Living Primates Research Group, School of Anthropology and Conservation, University of Kent, Canterbury, UK.
Centre for Social Learning and Cognitive Evolution, School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
Primates. 2020 Jan;61(1):69-82. doi: 10.1007/s10329-019-00730-3. Epub 2019 May 27.
Infanticide is well documented in chimpanzees and various hypotheses have been proposed to explain this behavior. However, since infanticide by chimpanzees is relatively rare, it has thus far not been possible to thoroughly test these hypotheses. Here we present an analysis of the largest dataset of infanticides from a single community of chimpanzees, a full record of all intra-community infanticides and failed attempts at infanticide over a 24-year period for the Sonso community of chimpanzees in the Budongo Forest, Uganda. We use these data to test four hypotheses for this behavior: the sexual selection hypothesis, male mating competition, resource competition, and meat acquisition. Our dataset consisted of 33 attacks on 30 victims, 11 of which were 'definite' infanticides, four of which 'almost certain', and nine were 'suspected', while nine were 'attempted' infanticides. The majority of attacks where the perpetrators were known (23) had only male attackers and victims were disproportionately young (two-thirds of victims with known ages were under 1 week old). Our data best support the sexual selection hypothesis for infanticide. Cannibalism was infrequent and partial, suggesting meat acquisition was a by-product of infanticide, and there was no evidence to suggest that infanticide was part of a male strategy to eliminate future competitors. Infanticide by females was rare, but we suggest sexual selection, operating through intra-sexual competition, may also be responsible for infanticide by females.
在黑猩猩群体中，杀婴行为有充分的记录，并且人们已经提出了各种假说来解释这种行为。然而，由于黑猩猩的杀婴行为相对罕见，迄今为止还无法对这些假说进行全面检验。在此，我们对来自乌干达布东戈森林中桑索黑猩猩群体的一个社区的最大规模杀婴数据集进行了分析，该数据集完整记录了24年间该群体内所有的社区内杀婴行为以及杀婴未遂事件。我们利用这些数据来检验关于这种行为的四个假说：性选择假说、雄性交配竞争、资源竞争和获取肉类。我们的数据集包括对30名受害者的33次攻击，其中11次是“确定的”杀婴行为，4次是“几乎确定的”，9次是“疑似的”，还有9次是“未遂的”杀婴行为。在已知作案者的大多数攻击事件（23次）中，只有雄性攻击者，而且受害者的年龄极不成比例地小（已知年龄的受害者中有三分之二不到1周大）。我们的数据最有力地支持了杀婴行为的性选择假说。同类相食的情况不常见且不完整，这表明获取肉类是杀婴行为的一个副产品，而且没有证据表明杀婴行为是雄性消除未来竞争对手策略的一部分。雌性的杀婴行为很少见，但我们认为，通过同性竞争起作用的性选择也可能是雌性杀婴行为的原因。
