Data from: Female competition in chimpanzees

Female chimpanzees exhibit exceptionally slow rates of reproduction and raise their offspring without direct paternal care. Therefore, their reproductive success depends critically on long-term access to high-quality food resources over a long lifespan. Chimpanzee communities contain multiple adult males, multiple adult females and their offspring. Because males are philopatric and jointly defend the community range while most females transfer to new communities before breeding, adult females are typically surrounded by unrelated competitors. Communities are fission–fusion societies in which individuals spend time alone or in fluid subgroups, whose size depends mostly on the abundance and distribution of food. To varying extents in different populations, females avoid direct competition by foraging alone or in small groups in distinct, but overlapping core areas within the community range to which they show high fidelity. Although rates of aggression are low, females compete for space and access to food. High rank correlates with high reproductive success, and high-ranking females win direct contests for food and gain preferential access to resource-rich sites. Females are aggressive to immigrant females and even kill the newborn infants of community members. The intensity of such aggression correlates with population density. These patterns are compared to those in other species, including humans.

雌性黑猩猩的繁殖速率异常缓慢，且无需雄性直接抚育即可抚养后代。因此，它们的繁殖成功率在很大程度上取决于能否在漫长的寿命中长期获取优质食物资源。黑猩猩社群包含多只成年雄性、多只成年雌性及其幼崽。由于雄性个体具有留居出生地的习性（philopatric），会共同防卫社群领地，而多数雌性在繁殖前会迁移至其他社群，因此成年雌性通常会被无亲缘关系的竞争者包围。黑猩猩社群属于裂变-融合（fission–fusion）社会，个体或独自活动，或组成流动性强的亚群，亚群规模主要取决于食物的丰度与分布情况。在不同种群中，雌性会通过不同程度的策略规避直接竞争：它们会在社群领地内各自专属但存在重叠的核心觅食区独自或小群体觅食，并对这些区域表现出高度的忠诚度。尽管攻击行为发生率较低，但雌性仍会为领地与食物获取权展开竞争。社会等级越高，繁殖成功率也越高；等级高的雌性可在食物的直接争夺中获胜，并优先获取资源丰富的觅食位点。雌性会对迁入的外来雌性展现出攻击行为，甚至会杀死社群内其他个体的新生幼崽。这类攻击行为的激烈程度与种群密度呈正相关。研究将这些行为模式与包括人类在内的其他物种进行了对比。