DISSERTATION RESEARCH: Reproductive Cooperation and Conflict in the White-Throated Magpie-Jay

白喉喜鹊（Calocitta formosa）是一种高度群居的鸟类，栖息在中美洲的热带干燥森林中，本研究将分析哥斯达黎加白喉喜鹊（Calocitta formosa）种群中亲属关系、亲子关系和行为变异之间的关系。在这种合作繁殖的鸟类中，领地群体通常由一对繁殖鸟、它们未成熟的后代和一个或多个助手（成年后代放弃自己的繁殖尝试，帮助繁殖者筑巢、抵御捕食者、喂养孵化中的雌性和她的雏鸟）组成。在大多数合作繁殖者中，雄性充当助手，但喜鹊特别有趣的是，这些性别角色是颠倒的：只有雌性留在后面。这为研究相关雌性之间的相互作用和评估影响雌性生殖决定的因素提供了难得的机会。具体来说，我们将测试一种最新的生殖行为模型，该模型预测了以下几种情况：1)雌性应该“寄生”在其他雌性的巢穴中产卵，2)单独繁殖，或3)在它们的出生地充当非繁殖助手。通过在野外环境中测试该模型的具体预测，将有可能评估影响雌性繁殖决策的因素，为未来研究鸟类合作与冲突之间的关系创造一个跳板。为了验证这一模型，将在三个繁殖季节收集多组喜鹊的行为和分子数据。将收集筑巢模式和帮助行为的观察数据，并对从成年和雏鸟身上收集的血液样本进行分子分析，以确定单个雌性的生殖产出以及群体内部和群体之间的亲属关系模式。这是一种令人兴奋的新方法，因为它为雌性的替代生殖策略提供了一个新的视角，为将合作繁殖和寄生联系起来提供了一个理论框架，并概述了可以在实地测试的具体预测。

eproductive cooperation and conflict in the white-throated magpie-jayJohn McAllister Eadie, PIElena Catherine Berg, co-PIThis study will analyze the relationship between kinship, parentage, and behavioral variation within a Costa Rican population of white-throated magpie-jays (Calocitta formosa), a highly gregarious bird inhabiting the tropical dry forests of Central America. In this cooperative breeding bird, territorial groups typically consist of a breeding pair, their immature offspring, and one or more helpers (adult offspring that forego their own breeding attempts and assist the breeders with nest-building, defense against predators, and feeding of the incubating female and her nestlings). In most cooperative breeders, males act as helpers, but the magpie-jay is particularly interesting in that these sex roles are reversed: only females stay behind. This provides a rare opportunity to study interactions between related females and assess the factors affecting female reproductive decisions. Specifically, we will test a recent model of reproductive behavior that predicts the precise conditions under which females should 1) lay eggs "parasitically" in the nests of other females, 2) breed alone, or 3) act as non-breeding helpers in their natal territory. By testing the specific predictions of this model in a field setting, it will be possible to evaluate the factors affecting reproductive decisions among females, creating a springboard for future research on the relationship between cooperation and conflict in birds. To test this model, behavioral and molecular data will be collected on multiple groups of magpie-jays during three breeding seasons. Observational data will be collected on patterns of nesting and helping behavior, and molecular analyses of blood samples collected from adults and nestlings will be used to establish the reproductive output of individual females as well as patterns of kinship within and among groups. This is an exciting new approach because it offers a fresh outlook on female alternative reproductive tactics, provides a theoretical framework for linking cooperating breeding and parasitism, and outlines specific predictions that can be tested in the field.