LTREB: Demography and Disease Ecology of a Colonial Bird

这项提案将继续对内布拉斯加州西南部悬崖燕子的人口统计学和社会行为进行长达25年的研究。 我们将监测生存，扩散，和殖民地选择的样本标记的鸟类，现在数字158,373人。 这些信息将被应用到正在进行的调查，纳入研究群体大小的影响，燕子种群生物学，也将被用来研究两个罕见的气候事件发生在1996年和2004年在研究区域的长期后果。 在过去的130年里，内布拉斯加州西南部只发生过两次这样的恶劣天气。 收集的数据将用于研究（1）与崖燕及其体外寄生虫相关的病毒的生态学和进化，我们正在研究这种脑炎相关病毒在研究区域内的群体之间通过鸟类传播的频率，给定年份的群体使用与病毒流行的关系，鸟类迁徙是否与研究区域内病毒亚型的进化分化模式有关，以及该病毒如何影响有标记的崖燕在几年内和几年之间的生存，从而在多大程度上代表了生活在殖民地的不利因素;（2）形态进化和繁殖时间的自然选择，研究罕见气候事件引起的个体大小的进化变化和翅、尾两侧不对称程度，以及2004年繁殖季节大范围的筑巢失败是否会对繁殖时间产生选择，导致提前产卵，在种群中代代相传。

This proposal is to continue a 25-year long study of demography and social behavior of cliff swallows in southwestern Nebraska. We will monitor survival, dispersal, and colony choice for a sample of marked birds that now numbers 158,373 individuals. This information will be applied to ongoing investigations of swallow population biology that incorporate study of the effect of group size, and will also be used to study the long-term consequences of two rare climatic events that occurred in the study area in 1996 and 2004. Severe weather of the timing and magnitude of these events has occurred in southwestern Nebraska only twice in the last 130 years. Data gathered will be applied to work on (1) the ecology and evolution of a virus associated with cliff swallows and their ectoparasites, in which we are studying how often this encephalitis-related virus is transmitted between colonies within the study area by birds, how colony use in a given year is related to prevalence of virus, whether bird movement is related to patterns of evolutionary divergence of virus subtypes within the study area, and how the virus affects survival of marked cliff swallows within and between years and thus to what degree it represents a disadvantage of living in colonies; and (2) morphological evolution and natural selection on breeding time, in which we are studying evolutionary changes in body size and extent of bilateral asymmetry in wings and tail brought about by the rare climatic events, and whether the widespread nesting failures in the 2004 breeding season will exert selection on breeding time and lead to earlier egg-laying in the population in successive generations.