DISSERTATION RESEARCH: Understanding effects of social behavior on extinction risk in avian cooperative breeders

众所周知，当种群数量较少时，一些社会行为会导致灭绝风险增加。例如，当个体很少时，针对捕食者的群体防御可能会崩溃。然而，人们对另一面--一些社会行为如何保护少数种群免于灭绝--知之甚少。由这笔拨款支持的研究重点是一种名为合作繁殖的不寻常的社会行为，即一年的后代放弃繁殖，以帮助他们的父母第二年抚养后代。有人提出，这种行为可以帮助种群在栖息地退化后生存下来。这项研究正在白胸鸟身上进行，这是一种生活在加勒比海两个小岛上的合作繁殖的鸟类。这种物种濒临灭绝，在最大的种群中只剩下1000只。它之所以特别令人感兴趣，是因为几年前，它的部分栖息地因创建度假村而受到影响。据预测，与合作繁殖者组成的群体规模将会增加。这项拟议的研究将实地工作与建模相结合，以确定合作繁殖作为该物种灭绝的可能缓冲和灭绝风险的作用。除了帮助了解灭绝风险外，这项工作还将直接有助于保护濒危物种。它被列入美国濒危物种法案，是世界上第二大濒危合作繁殖鸟类。这项研究的结果将为减少物种灭绝风险的管理行动提供参考，包括动物易位、森林恢复和自然保护区设计。此外，通过组织课后研讨会和本科生辅导，这项工作将利用鸟类教育加勒比和美国的年轻人关于生物多样性和科学研究。

It is well known that some social behaviors can lead to increased extinction risk when populations are small. For example, there can be a breakdown of group defense against predators when there are few individuals. However, less is known about the flipside -- how some social behaviors might protect small populations against extinction. Research supported by this grant is focused on an unusual social behavior called cooperative breeding, whereby offspring from one year forgo breeding to assist their parents in raising offspring the next year. It is proposed that this behavior can help populations survive after their habitat has been degraded. This is being studied in the White-breasted Thrasher, a cooperatively breeding bird that lives on two small islands in the Caribbean. This species is endangered, with only 1000 individuals remaining in the largest population. It is of particular interest because several years ago part of its habitat was impacted to create a resort. It is predicted that that groups with cooperative breeders will increase in size. The proposed research combines field work with modeling to determine the role cooperative breeding as a possible buffer to extinction and the extinction risk for this species. In addition to helping understand extinction risk, this work will contribute directly to conservation of an endangered species. It is listed on the U.S. Endangered Species Act and is the second-most endangered cooperatively breeding bird in the world. Results from this research will inform management actions to reduce extinction risk of the species, including animal translocations, forest restoration, and nature reserve design. In addition, through organization of after-school workshops and mentoring of undergraduates, this work will use birds to educate young people from both the Caribbean and the US about biological diversity and scientific research.