Doctoral Dissertation: Comparative Ecology of Brown Lemurs(Eulemur fulvus sspp): Analysis of Sympatric and Allopatric Popoulations in Southeastern Madagascar

博士论文：棕狐猴（Eulemur fulvus sspp）的比较生态学：马达加斯加东南部的同域和异域种群分析

• 批准号: 9910257
• 负责人: Deborah Overdorff
• 金额: $ 0.49万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-15 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9910257&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Comparative; Ecology; Brown

The study of competition has been a cornerstone of ecological research. Competition between related species may lead to exclusive ranges. Alternatively, similar species may develop behavioral or morphological differences in shared environments. These differences may serve two functions: 1) to mediate resource competition and 2) to reinforce reproductive barriers between species. The links between ecology and reproductive isolation form the basis of new and productive lines of inquiry.In Malagasy lemurs, competition appears to have played a significant role in structuring communities. Despite a wealth of information on related pairs of species, few studies have examined competition between different populations of the same species. The overlap of populations with incomplete reproductive isolation is the focus of much speciation research. Thus, these populations represent a compelling test case for examining the interface of community ecology and speciation. The present study proposes a 12-month field study of two brown lemur (Eulemur fulvus) subspecies in southeastern Madagascar. The project will investigate interactions between white-collared lemurs (E. f. albocollaris) and rufous lemurs (E. f. rufus) in a shared environment, as well as an isolated population of white-collared lemurs. Recent genetic studies suggest these animals may be separate species. However, natural hybrids are found at the boundary of their ranges. This area provides an opportunity to examine mechanisms of reproductive and ecological separation in these related populations. The major questions of the study are: 1) What are the ecological and behavioral factors that permit white-collared and rufous lemurs to overlap? 2) What are the variables that prevent further expansion beyond the area of overlap? 3) How do these variables contribute to the limitations of gene flow between the subspecies?To test these questions, the project will examine habitat structure, feeding ecology, population densities, and interactions between social groups. The following methods will be used: daily animal follows (recording feeding and social behavior), line transect censuses, and botanical sampling (including forest structure and food availability). In addition, genetic analyses will be conducted to clarify population affinities. Research will take place in consecutive seasons of resource scarcity (when niche separation is most marked) at one isolated white-collar lemur site and at one site in the area of subspecies overlap.This project will integrate areas of particular interest in ecology and evolutionary studies: competition and speciation. Moreover, this research will provide new evidence to assist in the conservation of one of Madagascar's most endangered primates.

竞争研究一直是生态学研究的基石。亲缘种之间的竞争可能导致排他性的范围。或者，相似的物种可能在共同的环境中发展出行为或形态上的差异。这些差异可能有两个功能：1)调节资源竞争；2)加强物种间的繁殖障碍。生态学和生殖隔离之间的联系构成了新的和富有成效的研究方向的基础。在马达加斯加狐猴中，竞争似乎在构建社区中发挥了重要作用。尽管有大量关于相关物种对的信息，但很少有研究调查同一物种不同种群之间的竞争。不完全生殖隔离的种群重叠是许多物种形成研究的焦点。因此，这些种群代表了一个令人信服的测试案例，用于研究群落生态学和物种形成的界面。本研究建议对马达加斯加东南部的两个棕色狐猴亚种进行为期12个月的实地研究。该项目将调查共享环境中白领狐猴（e.f. albocollaris）和红狐猴（e.f. rufus）之间的相互作用，以及孤立的白领狐猴种群。最近的基因研究表明，这些动物可能是不同的物种。然而，在它们活动范围的边界上发现了自然杂交。这一领域为研究这些相关种群的生殖和生态分离机制提供了机会。该研究的主要问题是：1)是什么生态和行为因素使白领狐猴和棕狐猴重叠？2)哪些变量会阻止进一步扩展到重叠区域之外？3)这些变量对亚种间基因流动的限制有何影响？为了验证这些问题，该项目将研究栖息地结构、饲养生态、人口密度以及社会群体之间的相互作用。将采用以下方法：每日动物跟踪（记录摄食和社会行为）、样线普查和植物抽样（包括森林结构和食物供应）。此外，还将进行遗传分析，以阐明种群的亲缘关系。研究将在连续的资源稀缺季节（生态位分离最明显的季节）在一个孤立的白领狐猴地点和亚种重叠区域的一个地点进行。这个项目将整合生态学和进化研究中特别感兴趣的领域：竞争和物种形成。此外，这项研究将为保护马达加斯加最濒危的灵长类动物之一提供新的证据。