Mechanistic models suggest that individuals’ memories could shape home range patterns and dynamics, and how neighbors share space. In social species, such dynamics of home range overlap may be affected by the pre-dispersal memories of immigrants. We tested this “immigrant knowledge hypothesis” in a wild population of chacma baboons (Papio ursinus). We predicted that overlap dynamics with a given neighboring troop’s home range should reflect males’ adaptive interests in overlap when the alpha male had immigrated from this neighboring troop but less so when the alpha male originated from elsewhere. We used data collected between 2005 and 2013 on two neighboring troops in Namibia, comprising GPS records of daily ranges, male natal origins, daily females’ reproductive status, and a satellite index of vegetation growth. We found support for our prediction in line with male reproductive strategies but not in line with foraging conditions. In periods with a higher relative number of fertile females over adult males in the focal troop, male baboons would benefit from reducing overlap with their neighbors to mitigate the costs of between-troop mating competition. This was indeed observed but only when the alpha male of the focal troop was an immigrant from that neighboring troop, and not with alpha males of other origins, presumably due to their different knowledge of the neighboring troop. Our findings highlight the role of reproductive competition in the range dynamics of social groups, and suggest that spatial segregation between groups could increase through the combination of dispersal and memory.

中文翻译：

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移民雄性的知识影响狒狒部队的移动，以减少家园范围重叠和交配竞争

机械模型表明，个人的记忆可以塑造家庭范围模式和动态，以及邻居如何共享空间。在社会物种中，这种家庭范围重叠的动态可能受到移民前分散记忆的影响。我们在野生狒狒（Papio ursinus）种群中测试了这种“移民知识假设”。我们预测，当阿尔法男性从这个邻近部队移民时，与给定相邻部队的家园范围的重叠动态应该反映男性在重叠中的适应性兴趣，但当阿尔法男性来自其他地方时，情况就不那么明显了。我们使用了 2005 年至 2013 年间在纳米比亚的两支邻近部队收集的数据，包括 GPS 记录的每日范围、男性出生地、每日女性的生殖状况以及植被生长的卫星指数。我们发现支持我们的预测符合雄性繁殖策略但不符合觅食条件。在焦点部队中可育雌性相对数量高于成年雄性的时期，雄性狒狒将受益于减少与邻居的重叠，以减轻部队间交配竞争的成本。确实观察到了这一点，但只有当焦点部队的阿尔法男性是来自邻近部队的移民时，而不是与其他来源的阿尔法男性一起，可能是由于他们对邻近部队的不同了解。我们的研究结果强调了生殖竞争在社会群体范围动态中的作用，并表明群体之间的空间隔离可以通过分散和记忆的结合而增加。