Doctoral Dissertation Improvement: The Reproductive Trajectories of Geladas (Theropithecus gelada)

在灵长类动物中，强烈的雄性纽带是罕见的，特别是对于雌性纽带物种。因此，男性结合和生殖策略之间的关系仍然在很大程度上未被审查的女性结合的物种。狮尾猿（Theropithecus gelada）提供了一个理想的模型，了解男性债券如何影响男性生殖轨迹的女性债券的物种。在获得与雌性的生殖机会之前，“单身”狮尾狒狒生活在有凝聚力的全雄性群体中。最终，雄性从这些群体中毕业，获得唯一的生殖机会，进入一个雌性群体（一个雄性单位）。单身汉们使用以下策略之一来获得一个男性单位：（1）直接推翻领导男性，（2）顺从地进入一个单位，并试图随着时间的推移将女性从单位中分离出来，或者（3）利用最近接管的混乱机会与女性交配。此外，单身汉们还被观察到合作，试图推翻男性领导者，并与他们以前的男性成员一起进入一个男性单位-但最终只有一个男性获得生殖利益。这个项目调查的行为和荷尔蒙因素，形状的繁殖轨迹狮尾狒狒男性，因为他们从一个全男性群体移动到一个男性单位。研究人员将（i）描述单身汉在他们的全男性群体中的社会互动;（ii）确定影响单身汉参与领导男性的接管尝试的行为和荷尔蒙因素，以及（iii）确定单身汉质量是否预测生殖策略。行为数据和非侵入性粪便激素采样将记录雄性狒狒的生殖轨迹。此外，还将拍摄男性胸部斑块颜色的数码照片--这是一个可能表明男性素质的特征--以记录男性从单身汉群体转移到一个男性单位时的颜色变化。这项研究的结果将为有关这些稀有灵长类动物的保护决策提供信息，而研究人员在西米恩山脉国家公园的存在有助于阻止在这个处于危险之中的世界遗产地进行非法活动。 该项目为当地埃塞俄比亚现场助理提供收入和培训，联合PI已安排向美国几个州的高中生解释狮尾狒狒的行为。

Strong male bonds are rare among primates, especially for female-bonded species. Thus, the relationship between male bonding and reproductive strategies remains largely unexamined in female-bonded species. Geladas (Theropithecus gelada) provide an ideal model for understanding how male bonds influence male reproductive trajectories in a female-bonded species. Prior to acquiring reproductive access to females, "bachelor" geladas live in cohesive all-male groups. Eventually, males graduate from these groups to gain sole reproductive access to a group of females (one-male unit). Bachelors acquire one-male units using one of several strategies: (1) directly overthrowing the leader male, (2) submissively entering a unit and attempting to pare females away from the unit over time, or (3) capitalizing on the chaos of a recent takeover to opportunistically mate with females. Additionally, bachelors have been observed to cooperate in attempts to overthrow leader males and enter one-male units with former members of their all-male group - yet only one male eventually reaps the reproductive benefits. This project investigates the behavioral and hormonal factors that shape the reproductive trajectory of gelada males as they move from an all-male group to a one-male unit. The researchers will(i) describe the social interactions among bachelors within their all-male group; (ii) determine the behavioral and hormonal factors that influence bachelor participation in takeover attempts of leader males, and (iii) determine whether bachelor quality predicts a reproductive strategy. Behavioral data and noninvasive fecal hormone sampling will document the reproductive trajectories of male geladas. Additionally, digital photographs will be taken of male chest patch color - a feature that may indicate male quality - to document changes in color as males move from their bachelor groups to one-male units. Results from this research will inform conservation decisions regarding these rare primates, and the investigator's presence in the Simien Mountains National Park help deter illegal activities in this World Heritage Site that is in danger. This project provides income and training to local Ethiopian field assistants and the co-PI has arranged to explain gelada behavior to high school students in several U.S. states.