The timing of female maturation in wild mammals is often constrained by ecological variables that relate to food acquisition. However, maturational timing in female mammals can also respond to social variables. Specifically, the arrival of novel males can accelerate maturation while the presence of related males can inhibit it. Despite studies on more than two dozen mammalian taxa in captivity, evidence for male-mediated maturation has not been systematically demonstrated in any wild population. Here, we report the first evidence of male-mediated maturation in a wild primate, the gelada (Theropithecus gelada). After the arrival of a new breeding male in the group (a male takeover), young females were three times more likely to mature. We then examined these takeover-associated maturations in more detail: some were earlier than expected (a presumptive “Vandenbergh effect,” or male-accelerated maturation), some were at the expected age for the average female gelada, and some were later than expected (a presumptive “inbreeding avoidance delay,” or father-induced reproductive suppression). An examination of fecal estrogens, which rise just before visible signs of maturation in this species, revealed that male takeovers induced a surge in estrogens for immature females of all ages—even females that did not mature. These are the first data to demonstrate that specific males are associated with the onset of maturation in a wild primate and to provide a possible mechanism for this change. These results suggest that all male-mediated maturation (whether accelerated, on-time, or delayed) may be governed by similar neuroendocrine processes.

野生哺乳动物雌性成熟的时间通常受到与食物获取相关的生态变量的限制。然而，雌性哺乳动物的成熟时间也会对社会变量做出反应。具体来说，新雄性的到来可以加速成熟，而相关雄性的存在可以抑制成熟。尽管对圈养的 20 多种哺乳动物分类群进行了研究，但尚未在任何野生种群中系统地证明雄性介导成熟的证据。在这里，我们报告了野生灵长类动物的雄性介导成熟的第一个证据，gelada（Theropithecus gelada）。在该组中出现新的繁殖雄性（雄性接管）后，年轻雌性成熟的可能性增加了三倍。然后，我们更详细地检查了这些与收购相关的成熟：有些比预期早（推定的“范登堡效应”，或男性加速成熟），有些处于普通雌性鸬鹚的预期年龄，有些比预期晚（推定的“近亲避免延迟”或父亲诱导的生殖抑制）。对粪便雌激素的检查显示，雄性接管会导致所有年龄段未成熟雌性的雌激素激增，即使是未成熟的雌性，该雌激素在该物种成熟的可见迹象之前就会升高。这是第一个证明特定雄性与野生灵长类动物的成熟开始相关的数据，并为这种变化提供了可能的机制。这些结果表明，所有男性介导的成熟（无论是加速、准时还是延迟）都可能受类似的神经内分泌过程控制。