U.S.-Madagascar Dissertation Enhancement: The Ranomafana Fragments Project

9912116 Patterson本学位论文增强补助金支持美国研究生Alex Dehgan先生在菲尔德博物馆动物学麦克阿瑟馆长Bruce Patterson博士的指导下在马达加斯加进行一项研究，研究不同的狐猴行为如何影响它们在森林碎片中的相对持久性，以及由此对狐猴种群的影响。为什么当它们支离破碎的小栖息地的大小减少时，一些物种而不是所有物种都会灭绝？行为已经在决定动物在栖息地碎片化中持续生存的能力方面发挥了重要作用，Dehgan理论认为，行为也将对栖息地碎片化如何影响特定物种在景观水平上的分布产生重大影响。他还预测，一个物种的行为灵活性(由其进化过程中形成的制约因素决定)的程度，以及它所拥有的行为特征，对于决定其灭绝的敏感性是重要的，这也将影响其在整个景观中的分布。马达加斯加的狐猴在一个与进化相关的单一单位内表现出非常不同的行为、社会制度和生态习性，它们提供了一个独特的机会来理解行为约束对零散景观中物种的复杂社会组织所起的作用。Dehgan将探索行为和生物地理之间的联系，以确定狐猴之间的行为差异如何影响它们在森林碎片中的相对持久性，他将试图揭示这种分布背后的最接近的机制。这项研究将在拉诺马法纳国家公园及其周围支离破碎的雨林栖息地中的12种狐猴身上进行。马达加斯加热带环境保护研究所的B.Andriamihaja博士和塔那那利佛大学的Berthe Rakotosamimanan教授将就这一项目向Dehgan先生提供指导。预期的结果将提供灭绝的生物地理模式与当地生态过程和行为之间的重要联系，这将有助于更好地理解导致局部灭绝的机制并确定动物分布，并将是对物种碎片化理论的重要新贡献。该项目由国际项目部和环境生物学部共同资助。

9912116PattersonThis dissertation enhancement grant supports a US graduate student, Mr. Alex Dehgan, working under the guidance of Dr. Bruce Patterson, MacArthur Curator of Zoology at The Field Museum, to conduct a study in Madagascar on how different lemur behaviors affect their relative persistence in forest fragments, and the resulting impact on lemur demographics. Why do some but not all species become extinct when the size of their small fragmented habitat is reduced? Behavior already has an important role in determining an animal's ability to persist in the midst of habitat fragmentation, and Dehgan theorizes that behavior will also have a significant effect on how habitat fragmentation impacts a particular species' distribution on the landscape level. He also predicts that the extent of a species' behavioral flexibility (as determined by constraints developed through the course of its evolution), and the behavioral characteristics that it possesses, are important for determining its susceptibility to extinction, which will also affect its distribution across the landscape. Madagascar's lemurs exhibit an extraordinarily diverse range of behaviors, social systems, and ecological habits within a single, evolutionarily-related unit, and they provide a unique opportunity to understand the role that behavioral constraint has on the complex social organization of a species in the midst of fragmented landscapes. Dehgan will explore the linkage between behavior and biogeography to determine how behavioral differences among lemurs affect their relative persistence in forest fragments, and he will seek to uncover the proximate mechanisms behind such distributions. The study will be conducted on 12 subsets of lemurs in fragmented rainforest habitats in and around Ranomafana National Park. Dr. B. Andriamihaja, of the Madagascar Institute for Conservation of Tropical Environments, and Professor Berthe Rakotosamimanan, of the University of Antananarivo, will provide guidance to Mr. Dehgan on this project.The expected results should provide an important link between biogeographic patterns of extinction and local ecological processes and behaviors, which will create a better understanding of the mechanisms that drive local extinction and determine animal distributions, and will be an important new contribution to fragmentation theories. This project is being jointly funded by the Division of International Programs and the Division of Environmental Biology.