DISSERTATION RESEARCH: Selective Pressures Shaping Aggressive Behavior in Females: An Experimental Approach

长期以来，动物行为中的一个假设是，雌性和雄性在交配策略上有根本的不同，雌性谨慎地选择配偶，而雄性相互竞争获得雌性和资源。越来越多的人意识到，女性也会积极竞争，这一假设受到了挑战。然而，目前尚不清楚女性是否直接受益于她们的攻击性，或者女性的攻击性行为是否是男性攻击性选择的副产品。这项拟议的研究以自由生活的树燕(Tachycineta Biolor)为模型，旨在了解影响雌性攻击行为的选择压力。初步研究表明，更具攻击性的雌性通过进入有限的筑巢地点而受益。然而，更具攻击性的雌性的后代发育较慢，因此可能会有较低的适合度。因此，女性也经历了与她们的攻击性相关的代价。拟议的研究使用实验和观察方法(1)测试更具攻击性的雌性的后代发育较慢的机制，以及(2)确定雄性的行为可能在多大程度上减轻雌性攻击性的代价。将攻击性作为女性的性选择特征来关注，提供了一个与已知的关于塑造男性性选择特征的选择压力的丰富信息相平行的迫切需要的信息。这项工作的更广泛影响包括关于动物行为和基础生物学的公共教育，保护洞巢鸟类，以及促进本科生和妇女的科学教育和培训。

A long-held assumption in animal behavior is that females and males differ fundamentally in their mating strategies, with females carefully choosing their mates, and males competing among themselves for access to females and resources. This assumption is challenged by the increasing realization that females also compete aggressively. It remains unclear, however, whether females benefit directly from their aggressiveness, or whether aggressive behavior in females is a byproduct of selection for aggressiveness in males. The proposed research aims to understand the selective pressures shaping aggressive behavior in females, using free-living tree swallows (Tachycineta bicolor) as a model. Preliminary work has demonstrated that more aggressive females benefit by gaining access to limited nest sites. Offspring of more aggressive females develop more slowly, however, and as a result, may have lower fitness. Thus, females also experience a cost associated with their aggressiveness. The proposed studies use experimental and observational approaches (1) to test mechanisms by which offspring of more aggressive females develop more slowly, and (2) to determine the extent to which the behavior of males may mitigate the cost of female aggressiveness. The focus on aggressiveness as a sexually selected trait in females provides a much needed parallel to the wealth of information already known about the selective pressures shaping sexually selected traits in males. The broader impacts of this work include public education about animal behavior and basic biology, conservation of cavity-nesting birds, and advancement of the scientific education and training of undergraduates and women in science.