Infanticide has been observed across many primate taxa, but the extent of its occurrence is not fully understood due to difficulty in observation and uneven reporting. Several hypotheses have been proposed to explain why infanticide occurs in primates and whether it benefits some individuals within a social group. Here we report on a case of infanticide, followed by partial consumption of the infant, in a population of Coquerel’s sifaka (Propithecus coquereli) at Mariarano, Northwest Madagascar. We witnessed an adult male sifaka kill and consume part of an infant, a member of his own social group, as well as the mother’s reaction to the infanticide. Following the infanticide, the mother of the deceased infant left the social group after repeated agonistic encounters with the other group members. We evaluate how this event relates to the predictions of four common hypotheses. Further research on Coquerel’s sifaka is needed to determine the frequency of infanticide in this species, and in lemurs more generally, because infanticide is currently poorly understood in this taxon.

中文翻译：

---

自由放养的 Coquerel sifaka (Propithecus coquereli) 的杀婴和部分自相残杀

在许多灵长类动物分类群中都观察到杀婴现象，但由于观察困难和报告不均，其发生的程度尚未完全了解。已经提出了几种假设来解释为什么灵长类动物会发生杀婴行为以及它是否有益于社会群体中的某些个体。在这里，我们报告了一起在马达加斯加西北部马里亚拉诺的 Coquerel sifaka (Propithecus coquereli) 种群中杀死婴儿，随后部分食用婴儿的案例。我们目睹了一只成年雄性狼蛛杀死并吃掉了一个婴儿的一部分，这是他自己社会群体的成员，以及母亲对杀婴的反应。杀婴事件发生后，死婴的母亲在与其他群体成员反复激战后离开了社会群体。我们评估了该事件与四种常见假设的预测之间的关系。需要对 Coquerel's sifaka 进行进一步研究，以确定该物种以及更普遍的狐猴中杀婴的频率，因为目前对该分类群的杀婴行为知之甚少。