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

9912116Patterson这项论文强化资助支持美国研究生Alex Dehgan先生在Field博物馆麦克阿瑟动物学馆长Bruce Patterson博士的指导下，在马达加斯加进行一项研究，研究狐猴的不同行为如何影响它们在森林碎片中的相对持久性，以及由此对狐猴人口统计的影响。为什么当它们小而分散的栖息地面积减少时，有些而不是所有的物种会灭绝？行为已经在决定动物在栖息地破碎中坚持的能力方面发挥了重要作用，Dehgan认为，行为也将对栖息地破碎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约束决定）的程度，以及它所拥有的行为特征，对于决定它对灭绝的易感性很重要，这也将影响它在整个景观中的分布。马达加斯加的狐猴在一个进化相关的单一单位中表现出异常多样化的行为、社会系统和生态习惯，它们提供了一个独特的机会，让我们了解在破碎的景观中，行为约束对物种复杂社会组织的作用。Dehgan将探索行为和生物地理学之间的联系，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，他将寻求揭示这种分布背后的近似机制。这项研究将在Ranomafana国家公园及其周围的破碎雨林栖息地的12个狐猴亚群中进行。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教授将在这个项目上为Dehgan先生提供指导。研究结果为物种灭绝的生物地理格局与局部生态过程和行为之间提供了重要的联系，有助于更好地理解局部物种灭绝和动物分布的驱动机制，并将为碎片化理论提供重要的新贡献。本项目由国际项目司和环境生物司共同资助。

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.