Fitness Consequences of Avian Coloniality

9613638布朗这个项目旨在了解为什么动物生活在群体。 许多不同的生物，包括人类，表现出不同程度的群体生活：一些动物生活在小群体中或独居，而同一种群中的其他动物可能居住在巨大的群体中。 要理解为什么有些人喜欢生活在大群体中，而另一些人喜欢生活在小群体中，就需要了解这种选择的生殖后果。 某些动物从一种规模的群体中受益，而另一些动物显然从另一种规模的群体中受益，这是以什么方式实现的？ 这个问题在这项研究中得到了解决，这项研究的重点是一种殖民地繁殖的鸟类，悬崖燕子（_Hirundo pyrrhonota_），它在陡峭的悬崖和峡谷两侧以及北美西部大部分地区的桥梁和建筑物的屋檐下繁殖。 目的是确定不同的鸟类如何在不同大小的筑巢群体中进行自我排序，以及基于什么基础;是否有一个单一的群体大小对所有鸟类都是最好的（繁殖成功率最高）;燕子对特定大小的筑巢群体的偏好是否基于遗传，因此从父母那里继承;以及鸟类的筑巢成功率如何 如果筑巢地的大小发生变化， 该研究主要使用标记-再捕获方法，其中包括鸟类环志：在特定地点环志鸟类，并通过在该地点或以后的其他地点重新捕获它们来确定它们随后的活动和寿命。 这项研究建立在过去15年对这一悬崖燕子种群的研究基础上。 这个项目将进一步了解为什么动物群体的大小在自然界中各不相同。 群体规模影响动物行为的许多方面：例如，疾病的传播，对食物等资源的竞争程度，交配策略的类型，以及个体之间的合作和利他主义程度都受到社会群体规模的严重影响。 我们可以 如果我们首先知道是什么原因导致群体的大小不同，如果我们知道不同的群体是否由不同种类的个体组成，我们就能更好地理解群体生活的这些重要后果。 崖燕提供了一个研究得很好的动物模型，其社会行为与其他社会物种相似，它将使人们深入了解基本的 在许多生物中控制群体形成的过程。

9613638 BROWN This project seeks to understand why animals live in groups. Many different organisms, including humans, show different degrees of group-living: some animals live in tiny groups or solitarily, whereas others in the same population may reside in enormous colonies. To understand why some individuals prefer living in large groups and others in small groups requires knowing the reproductive consequences of such choices. In what way do certain animals benefit from groups of one size while others apparently benefit from groups of another size? This question is addressed in this research, which focuses on a colonially breeding bird, the cliff swallow (_Hirundo pyrrhonota_), that breeds on the sides of steep cliffs and canyons and underneath the eaves of bridges and buildings throughout much of western North America. The objectives are to determine how different birds sort themselves among different sized nesting colonies and on what basis; whether there is a single colony size that is best for all birds (where reproductive success is greatest); whether a swallow's preference for a particular sized nesting colony is genetically based and thus inherited from its parents; and how the birds' nesting success is affected if their nesting colony is changed in size. The research uses primarily mark-recapture methods that involve bird banding: birds are banded at a particular site and their subsequent activity and lifespan is determined by recatching them at that site or others in later years. This study builds on 15 years of past work on this cliff swallow population. This project will further our understanding of why animal group sizes vary in nature. Group size affects many aspects of animal behavior: for example, the spread of disease, extent of competition for resources such as food, type of mating strategy, and extent of cooperation and altruism among individuals are all influenced heavily by the size of a social group. We can better understand these important conseque nces of group life if we know what causes groups to vary in size in the first place and if we know whether different groups are composed of different kinds of individuals. The cliff swallow provides a well-studied animal model whose social behavior parallels that of other social species, and it will yield insight into fundamental processes that govern group formation in many kinds of organisms.