Wroblewski Emily E, Murray Carson M, Keele Brandon F, Schumacher-Stankey Joann C, Hahn Beatrice H, Pusey Anne E
Jane Goodall Institute's Center for Primate Studies, Department of Ecology, Evolution and Behavior, University of Minnesota, Twin Cities, MN, U.S.A.
Anim Behav. 2009;77(4):873-885. doi: 10.1016/j.anbehav.2008.12.014.
Competition for fertile females determines male reproductive success in many species. The priority of access model predicts that male dominance rank determines access to females, but this model has been difficult to test in wild populations, particularly in promiscuous mating systems. Tests of the model have produced variable results, probably because of the differing socioecological circumstances of individual species and populations. We tested the predictions of the priority of access model in the chimpanzees of Gombe National Park, Tanzania. Chimpanzees are an interesting species in which to test the model because of their fission-fusion grouping patterns, promiscuous mating system and alternative male mating strategies. We determined paternity for 34 offspring over a 22-year period and found that the priority of access model was generally predictive of male reproductive success. However, we found that younger males had higher success per male than older males, and low-ranking males sired more offspring than predicted. Low-ranking males sired offspring with younger, less desirable females and by engaging in consortships more often than high-ranking fathers. Although alpha males never sired offspring with related females, inbreeding avoidance of high-ranking male relatives did not completely explain the success of low-ranking males. While our work confirms that male rank typically predicts male chimpanzee reproductive success, other factors are also important; mate choice and alternative male strategies can give low-ranking males access to females more often than would be predicted by the model. Furthermore, the success of younger males suggests that they are more successful in sperm competition.
在许多物种中，对可育雌性的竞争决定了雄性的繁殖成功率。优先接触模型预测，雄性的优势等级决定了其接近雌性的机会，但该模型在野生种群中很难得到验证，尤其是在混交的交配系统中。对该模型的测试产生了不同的结果，这可能是由于各个物种和种群的社会生态环境不同。我们在坦桑尼亚贡贝国家公园的黑猩猩中测试了优先接触模型的预测。黑猩猩是测试该模型的一个有趣物种，因为它们具有裂变融合的群体模式、混交的交配系统以及雄性的替代交配策略。我们在22年的时间里确定了34个后代的父系，发现优先接触模型通常能够预测雄性的繁殖成功率。然而，我们发现年轻雄性的平均繁殖成功率高于年长雄性，而且地位较低的雄性所生后代比预期的更多。地位较低的雄性与更年轻、吸引力较小的雌性生育后代，并且比地位较高的雄性更频繁地进行配偶陪伴。虽然首领雄性从未与近亲雌性生育后代，但避免近亲繁殖并不能完全解释地位较低雄性的成功。虽然我们的研究证实雄性等级通常能预测雄性黑猩猩的繁殖成功率，但其他因素也很重要；配偶选择和雄性的替代策略使地位较低的雄性比模型预测的更频繁地接触到雌性。此外，年轻雄性的成功表明它们在精子竞争中更成功。
