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

在动物行为中，一个长期存在的假设是，雌性和雄性在交配策略上有着根本的不同，雌性会仔细选择配偶，而雄性则会为了获得雌性和资源而相互竞争。 这一假设受到越来越多的认识的挑战，女性也积极竞争。 然而，目前还不清楚雌性是否直接受益于它们的攻击性，或者雌性的攻击性行为是否是雄性攻击性选择的副产品。 这项拟议中的研究旨在了解选择压力塑造女性的攻击行为，使用自由生活的树燕（Tachycineta bicolor）作为模型。 初步工作表明，更具侵略性的女性受益于获得有限的巢址。 然而，更具攻击性的雌性的后代发育较慢，因此可能具有较低的适应性。 因此，女性也经历了与其侵略性相关的成本。 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后代发育较慢的机制，以及（2）确定雄性行为在多大程度上可以减轻雌性攻击性的代价。 对攻击性作为女性性选择特征的关注，提供了一个非常需要的平行信息已经知道的选择压力塑造男性性选择特征的财富。 这项工作的更广泛的影响包括关于动物行为和基础生物学的公共教育，保护洞穴筑巢的鸟类，以及促进科学教育和本科生和妇女在科学方面的培训。

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.