EAGER: Climatic drivers of demography and reproductive behavior of tropical birds

天气对动物在哪里被发现以及它们如何生活有很大的影响。关于温度的季节模式（冬季和夏季）如何影响我们周围的动物，我们知道很多，但我们很少考虑降雨的季节模式如何以相当不同的方式影响动物。这种影响在赤道附近尤其可能发生，因为那里的温度一直很高，季节在“湿”和“干”之间摇摆不定。这个项目将测试一种热带鸟类是如何在一个经历极高降雨量的地区茁壮成长的。这种类型的研究对于帮助我们了解气候变化如何影响动物非常重要，特别是在热带这样的地方，那里有大量其他地方找不到的物种。这项研究的结果有可能改变我们对气候在热带生物生命中的作用的看法。热带生态学的一个经典范例是，全年的温暖和湿度将生物体从气候压力和约束中解放出来，使它们从能量限制中解放出来，并提高了生物相互作用在塑造生命史和行为方面的重要性。这个项目在智力上是有风险的，因为它挑战了这种根深蒂固的观点。研究者提出降水极值限制了适应度，并验证了降水-适应度关系是单峰关系的假设。这项工作建立在对中美洲山区森林中一种小型的、热带的、食果的、繁殖青菜的鸟——白颈金雀（Corapipo altera）——进行了十多年的研究之上。研究者将阐明侏儒猴对长期平均降水制度和短期降雨事件变化的反应，这些变化跨越了哥斯达黎加太平洋和加勒比斜坡上中度潮湿到极度潮湿的森林。人们将在高降雨量与侏儒动物的生存、身体状况和繁殖之间寻找机械联系。此外，先前记录的生殖行为和lek属性将与加勒比斜坡上两个新的焦点种群的数据进行对比，以测试所提出的气候对lek性选择行为的限制。该团队将指导两名博士生和四名本科生进行研究，并制作供公立学校使用的教育材料。

Weather has a large impact on where animals are found and how they live. We know a lot about how seasonal patterns of temperature (winter vs. summer) impact the animals around us, but we rarely consider how seasonal patterns of rainfall might impact animals in considerably different ways. Such impacts are especially likely near the equator, where the temperature is always high and seasons can swing dramatically between "wet" and "dry". This project will test how a tropical bird manages to thrive in an area that experiences periods of extremely high rainfall. This type of study is important for helping us understand how changing climate may impact animals, especially in places like the tropics that contain a large number of species that are found nowhere else. Results of this research have the potential to change how we view the role of climate in the lives of tropical organisms. One of the classic paradigms in tropical ecology is that year-round warmth and humidity frees organisms from climatic stressors and constraints, releasing them from energetic limitations and heightening the importance of biological interactions in shaping life history and behavior. This project is intellectually risky because it challenges this deeply entrenched view. The investigator proposes that precipitation extremes limit fitness and tests the hypothesis that precipitation-fitness relationships are unimodal. The work builds upon more than a decade of studies on a small, tropical, frugivorous, lek-breeding bird -- the White-ruffed Manakin (Corapipo altera) -- in Central American montane forests. The investigator will elucidate responses of manakins to variation in long-term mean precipitation regimes and short-term rainfall events across populations spanning moderately wet to extremely wet forests on both the Pacific and Caribbean slopes of Costa Rica. Mechanistic links will be sought between high rainfall and manakin survival, body condition, and reproduction. Additionally, previously-documented reproductive behavior and lek attributes will be contrasted with data from two new focal populations on the Caribbean slope, testing proposed climatic constraints on sexually-selected behavior at leks. Two PhD students and four undergraduate students will be mentored in research and the team will produce educational materials for use in public schools.