LTREB/SG: Spatiotemporal fitness variation and avian group size

许多社会有机体生活在大小不一的群体中。群体规模有许多重要后果，例如影响传染病在群体内和向其他群体成员的传播和传播。这个项目试图理解为什么不同大小的群体在长期时间尺度上持续存在。随着我们更好地理解是什么促进了群体规模的变化，我们就可以更好地预测群体生活的成本或收益将随着时间的推移而发生变化的程度。一个流行但未经检验的假设是，不同年份之间的气候差异会导致食物供应或寄生虫和病原体种群的变化，这反过来又会导致不同群体规模的收益每年都不同。这个项目建立在对群居鸟类悬崖燕子的长期研究基础上，这种燕子生活在大小迥异的群体中，试图调查改变对动物生存和繁殖成功的选择是否可以解释群体规模的年度变化。这项研究解决了进化生态学中最基本的问题之一。这个项目将检验这样的预测，即个人的成功在某些年份会随着群体规模的增加而增加，在另一些年份随着群体规模的增加而减少，而在其他年份保持不变。这将决定在不同大小的鸟群中，这些鸟每年的筑巢成功程度有多大。这将通过每年在20-25个殖民地系统地收集数据来进行调查。这项工作将通过测量寄生虫感染的程度、繁殖时间、鸟类状况和其他因素来确定繁殖成功率变化的原因。这项研究将促进更好地理解群体规模如何影响个体在长期时间尺度上的终生繁殖成功，有助于解释许多生物所特有的群体规模的广泛差异，并揭示最近气候变化对社会行为的潜在影响。这项研究将涉及妇女、美洲原住民和来自大平原的学生，促进对代表人数不足的群体进行性别、种族和地理区域方面的STEM培训。

Many social organisms live in groups of variable size. Group size has many important consequences, such as affecting the spread and transmission of infectious diseases both within the group and to members of other groups. This project seeks to understand why groups of variable size persist over long-term time scales. As we better understand what promotes variability in group size, we can better predict the extent to which the costs or benefits of group living will change over time. One popular but untested hypothesis is that climatic differences between years cause variation in food supply or in populations of parasites and pathogens, and this in turn causes the payoffs of different group sizes to vary annually. This project builds on a long-term study of a social bird, the cliff swallow, which lives in colonies of widely different sizes, and seeks to investigate whether changing selection on the animals' survival and reproductive success can explain annual variation in group size. The research addresses one of the most fundamental questions in evolutionary ecology. This project will test the prediction that success of individuals will increase with group size in some years, decrease with group size in others, and remain unchanged in yet other years. It will be determined to what degree the birds' annual nesting success varies from year to year in colonies of different sizes. This will be investigated by systematically collecting data at 20-25 colonies each year. The work will determine the causes of variation in reproductive success by measuring the extent of parasite infestation, time of breeding, bird condition, and other factors. This study will promote better understanding of how group size affects individuals' lifetime reproductive success across long-term time scales, assist in interpreting the extensive variation in group size that is characteristic of many organisms, and reveal the potential influence of recent climatic changes on social behavior. The research will involve women, Native Americans, and students from the Great Plains, promoting STEM training of underrepresented groups with respect to gender, ethnicity, and geographic region.