Countering infanticide: Chimpanzee mothers are sensitive to the relative risks posed by males on differing rank trajectories
Countering infanticide: Chimpanzee mothers are sensitive to the relative risks posed by males on differing rank trajectories
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DOI：
10.1002/ajpa.23723
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发表时间：
2019-01-01
影响因子：
2.8
通讯作者：
Newton-Fisher, Nicholas E.
中科院分区：
文献类型：
--
作者：
Lowe, Adriana E.;Hobaiter, Catherine;Newton-Fisher, Nicholas E.
目的雄性杀婴在哺乳动物中很常见。根据性选择假说，风险与婴儿年龄呈负相关，因为婴儿年龄越大，杀精剂缩短哺乳期闭经的可能性越小;当杀精剂男性生下替代婴儿的机会很高时，风险也会增加。杀婴发生在黑猩猩（Pan troglodytes）中，这是一种雄性优势地位预示着父权倾斜的物种。杀婴的雄性黑猩猩（如果等级低）不太可能杀死自己的后代，而那些等级正在上升的黑猩猩，特别是当这种上升是戏剧性的时候，相对于任何现有的婴儿，有更大的可能性成为未来婴儿的父亲。考虑到母亲的行为方式应该降低杀婴风险，我们预测雌性黑猩猩，特别是那些有更年轻、更脆弱婴儿的雌性黑猩猩，会试图调整婴儿与潜在杀婴雄性的接触。具体来说，年幼婴儿的母亲一般应减少与成年男性的联系，并在更大程度上减少与地位较低的男性和地位从当前婴儿的父亲身份不太可能上升到下一个婴儿的可能性显着更高的地位的男性的联系。我们还调查了另一种可能性，而不是避免所有成年男性，母亲会增加与男性的稳定的高级别的基础上，这种男性可以提供保护，防止admincide.Materials和方法，我们研究了从布东戈森林，乌干达收集的女性协会模式的数据，在男性等级相对稳定的时期和中等男性等级迅速上升的不稳定时期。结果使用线性混合模型，我们发现，在不稳定时期，母亲减少了与排名上升的男性的联系，这取决于婴儿的年龄。我们还发现的证据表明，女性优先与一个潜在的保护者男性在high-riskperiod.Discussion我们的研究结果支持性选择的假设，杀黑猩猩剂，并表明，雌性黑猩猩是敏感的成年男性所带来的相对风险。
Objectives Infanticide by males is common in mammals. According to the sexual selection hypothesis, the risk is inversely related to infant age because the older the infant, the less infanticide can shorten lactational amenorrhea; risk is also predicted to increase when an infanticidal male's chance of siring the replacement infant is high. Infanticide occurs in chimpanzees (Pan troglodytes), a species in which male dominance rank predicts paternity skew. Infanticidal male chimpanzees (if low-ranking) are unlikely to kill their own offspring, whereas those who are currently rising in rank, particularly when this rise is dramatic, have an increased likelihood of fathering potential future infants relative to any existing ones. Given that mothers should behave in ways that reduce infanticide risk, we predicted that female chimpanzees, and specifically those with younger, more vulnerable infants, would attempt to adjust the exposure of their infants to potentially infanticidal males. Specifically, mothers of young infants should reduce their association with adult males in general, and to a greater extent, with both low-ranking males and those rising in rank from a position where paternity of current infants was unlikely, to a rank where the probability of siring the next infant is significantly higher. We also investigated the alternative possibility that rather than avoiding all adult males, mothers would increase association with males of stable high rank on the basis that such males could offer protection against infanticide.Materials and methods We examined data on female association patterns collected from the Budongo Forest, Uganda, during a period encompassing both relative stability in the male hierarchy and a period of instability with a mid-ranking male rising rapidly in rank.Results Using linear mixed models, we found that mothers reduced their association with the rank-rising male, contingent on infant age, during the period of instability. We also found evidence that females preferentially associated with a potential protector male during the high-risk period.Discussion Our results support the sexually selected hypothesis for infanticide and demonstrate that female chimpanzees are sensitive to the relative risks posed by adult males.