An Experimental Test of An Avian Life History Model

在某些物种中，一些成熟的个体，被称为帮手， 帮助别人抚养后代而不是自己繁殖后代。 这种合作育种的研究已经非常 在理论的发展中富有成效， 动物社会行为的进化基础 本研究 将测试一个被称为栖息地饱和度的一般理论， 将群体的形成与幼鸟在环境中的保留联系起来 其中扩散的机会是有限的。 的 调查人员建议，那些留在他们的 纳塔尔组作为助手，而不是分散练习， 获取高质量领土的战略。 物种 他们正在研究的是在生活中建造洞穴的独特之处， 松树，研究人员提出，鸟类寻求 获取现有洞穴的领土，而不是花费 需要大量的时间和精力来建造洞穴， 以前被占领。 先前的研究表明， 与这个假设是一致的。 个人作为 帮助者通过取代先前的繁殖者而成为繁殖者。 就在它们纳塔尔地附近 有些人继承了纳塔尔 领土，其他人搬到相邻的群体。 与此相反的是， 不作为帮手的人，也就是说，在 雏鸟会四处游荡，可能会迁移到远离纳塔尔的地方 绝佳的价钱 这项研究将检验关于 生境饱和度和领土质量的生态基础， 在无人居住的栖息地建造洞穴。 据预测 一旦洞穴被破坏， 礼物 在进行这项研究时，研究人员将监测 每年有超过500条成年蛇 这些数据提供了一个 所有鸟类的最佳人口统计样本 这是 特别重要的是，红冠啄木鸟是一种 美国联邦濒危物种，以及 其人口动态令人极为关切。 这个实验， 如果成功，将提供第一个已知的方法， 这种稀有鸟类的数量可以通过 管理

In some species, some mature individuals, called helpers, assist others in raising young rather than reproduce themselves. Studies of such cooperative breeding have been extremely productive in the development of theory related to the evolutionary basis of social behavior in animals. This research will test a general theory known as habitat saturation, which relates group formation to retention of young in an environment in which opportunities for dispersal are limited. The investigators propose that individuals which remain in their natal group as helpers rather than disperse are practicing a strategy for acquiring high quality territories. The species they are studying is unique in constructing cavities in living pine trees, and the investigators propose that birds seek to acquire territories with existing cavities rather than expend the great time and energy required to construct cavities in areas not previously occupied. Previous research showed that the behavior of this species is consistent with this hypothesis. Individuals that serve as helpers become breeders by replacing previous breeders in the immediate vicinity of their natal territory. Some inherit natal territory, others move to adjacent groups. In contrast, individuals that do not serve as helpers, that is, disperse after fledging, wander and may move to territories far from their natal site. This research will test the hypothesis about the ecological basis of habitat saturation and territory quality by constructing cavities in unoccupied habitat. It is predicted that birds will occupy these territories once cavities are present. In conducting this research, the investigators will monitor over 500 banded adults each year. These data provide one of the best demographic samples available for any bird. This is particularly important because the red-cockaded woodpecker is a federally endangered species endemic to the United States, and its population dynamics are of great concern. This experiment, if successful, will provide the first known means by which populations of this rare bird can be increased through management.