CAREER: The evolution of female alternative reproductive tactics in a cooperative bird

个体行为差异在动物界很普遍，目前还不清楚这种行为差异是如何影响动物的繁殖和生存的。大鳗是一种成群筑巢的热带鸟类：几只雌性鸟在一个共同的巢中产卵，并帮助抚养这群混合的雏鸟。然而，一些雌性大猩猩充当生殖寄生虫，将它们的卵放入群体的巢中，但不提供父母的照顾。因此，雌性ANI可以使用两种不同的繁殖策略：她可以在一个合作的群体中筑巢，帮助抚养自己的后代，或者她可以充当寄生虫，让另一个群体来做所有的工作。但是，为什么一些雌鸟合作筑巢，而同一种群中的另一些雌鸟则像寄生虫一样行动呢？这个项目的一个目标是了解这种行为差异是由潜在的遗传差异造成的，还是由雌性历史上的差异(例如，她们的身体状况或她们在发育期间获得的营养)造成的。一个相关的目标是了解女性的生殖行为如何影响她的男性配偶。如果雄性与寄生的雌性配对更成功，还是与合作的雌性配对更成功？相反，雄性的行为是否会影响其配偶是作为寄生虫还是合作者？这项研究可以对生殖行为变异发生的原因以及雄性和雌性如何协调行为以获得最大的生殖成功提供重要的见解。该项目的实地工作将在巴拿马进行，为美国低收入高中生和大学生创造形成研究经验的机会。最后，它将使人们能够参与新泽西州监狱的教学计划，该计划服务于全国最被忽视和服务最少的人群之一。行为策略的个体差异构成了一个持久的进化谜题。什么时候选择应该倾向于同一问题的不同解决方案，而不是单一的最优？破坏性选择，即中间行为表型的适合度低于极端选择，被认为在雄性动物替代生殖策略(ARTS)的进化中发挥着关键作用。然而，影响女性艺术的进化动力和直接机制仍然鲜为人知，尽管这样的策略很普遍。大乌鸦是一种在社会群体中筑巢的热带鸟类，它提供了一个独特的机会来回答关于女性艺术进化的基本问题。雌性通常在公共巢中产卵，分享繁殖和父母照顾；然而，一小部分雌性一直充当生殖寄生虫，将卵产下宿主群体的巢中，但不提供父母照顾。广泛的寄生和非亲属合作的共存为检验长期存在的关于女性艺术进化起源和维持的假说提供了一个理想的系统。该项目的目标是1)评估生殖投资的破坏性选择是否倾向于离散的寄生和群体策略；2)调查决定这些策略表达的环境和遗传机制；3)了解替代的女性策略和男性适应之间的进化反馈。关于个体生殖行为的数据将从巴拿马的一个长期实地地点收集，从而能够直接估计有色人种的遗传力、生殖产出和生殖投资。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Individual variation in behavior is widespread in the animal kingdom and it is still unclear how this variation in behavior impacts reproduction and survival in animals. The greater ani is a tropical bird that nests in groups: several females lay their eggs in a shared nest and help to raise the mixed clutch of nestlings. However, some females act as reproductive parasites, laying their eggs into a group's nest but providing no parental care. A female ani can therefore use two alternative tactics for reproduction: she can nest in a cooperative group and help to raise her own young, or she can act as a parasite and let another group do all of the work. But why do some females nest cooperatively, whereas others, in the same population, act as parasites? One goal of this project is to understand whether this behavior difference is due to underlying genetic differences, or whether it results from differences in the females' histories (for example, their body condition or the nutrition that they received during development). A related goal is to understand how a female's reproductive behaviors affect her male mate. Are males more successful if they pair with a parasitic female, or a cooperative female? Conversely, does a male's behavior affect whether his mate acts as a parasite or a cooperator? This research can provide significant insight into why reproductive behavioral variation occurs and how males and females coordinate behavior for maximal reproductive success. Field work for this project will take place in Panama, creating opportunities for formative research experiences for low-income high school and college students in the U.S. Finally, it will enable participation in a New Jersey state prison teaching program that serves one of the most neglected and under-served populations in the country.Individual variation in behavioral strategies poses an enduring evolutionary puzzle. When should selection favor divergent solutions to the same problem, instead of a single optimum? Disruptive selection, in which intermediate behavioral phenotypes have lower fitness than extreme alternatives, is thought to play a crucial role in the evolution of alternative reproductive tactics (ARTs) in male animals. However, the evolutionary dynamics and proximate mechanisms influencing female ARTs remain poorly understood, although such strategies are widespread. The greater ani (Crotophaga major), a tropical bird that nests in social groups, provides a unique opportunity to answer fundamental questions about the evolution of female ARTs. Females typically lay their eggs in communal nests and share reproduction and parental care; however, a small minority of females consistently act as reproductive parasites, laying their eggs into the nest of a host group but providing no parental care. The co-existence of widespread parasitism and non-kin cooperation offers an ideal system in which to test long-standing hypotheses about the evolutionary origins and maintenance of female ARTs. The goals of this project are to 1) evaluate whether disruptive selection on reproductive investment favors discrete parasitic and communal tactics; 2) investigate the environmental and genetic mechanisms determining the expression of these strategies; and 3) understand evolutionary feedbacks between alternative female strategies and male fitness. Data on individual reproductive behaviors will be collected from a long-term field site in Panama, enabling direct estimates of heritability, reproductive output, and reproductive investment from a color-marked population.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.