Doctoral Dissertation Research: Habitat Quality and Stress: Fecal Cortisol Levels in Three Species of Malagasy Lemurs (Varecia variegata, Eulemur Fulvus rufus & Eulemur rubrive

长期暴露在环境和社会压力下会抑制脊椎动物的繁殖和免疫功能。由于灵长类动物的繁殖和后代发育速度较慢，受这些压力源影响的灵长类动物的终生生殖成功率比其他哺乳动物更严重。狐猴对生态压力尤其敏感，因为马达加斯加的环境异常恶劣且难以预测。与其他灵长类动物相比，狐猴的一些独特特征（如雌性优势、灵活的活动模式、小群体规模）被认为是对生态压力的适应，在紧张的环境中保存能量和最大化资源。然而，很少进行实地研究来验证这一假设。人们对自然栖息地的应激反应知之甚少。皮质醇是一种对压力做出反应时释放的激素，它的测量可以定量地评估野生动物的压力源，而且不需要动物处理。将构建年度激素概况，以确定生态和生殖相关的皮质醇排泄。本研究以红腹狐猴（Eulemur rubriventer）为模型，以皮质醇为应激指标，研究马达加斯加Ranomafana国家公园的食物丰度、繁殖和栖息地质量如何相互作用。下面将探讨：(1)食物丰度的波动是否反映在皮质醇水平上？(2)不同的生殖阶段是否反映在皮质醇水平上？(3)婴儿断奶与特定生态事件同步是否抵消了该活动的成本？(4)生境干扰是否影响对食物丰度和繁殖的应激反应的持续时间和强度？除了与了解狐猴进化相关外，该项目还将使未来与其他狐猴物种的研究进行比较，这将有助于识别更容易受到压力影响的物种。构建马达加斯加灵长类动物的激素谱也将为与其他不受马达加斯加独特环境影响的地区的灵长类动物进行比较提供基础。这项研究将继续为马达加斯加和非马达加斯加大学生提供实地考察和数据收集的实践经验。马达加斯加学生还将获得完成硕士学位的学术和经济支持。公开讲座将促进与当地人民的互动，并将与塔那那利佛大学的教员进行合作。最终报告将提交给公园机构，以促进马达加斯加的保护工作，并促进与该地区其他研究人员的科学合作。

Exposure to prolonged environmental and social pressures can inhibit reproduction and immune function in vertebrates. The lifetime reproductive success of primates impacted by these stressors is reduced more severely than in other mammals due to the slow rate of reproduction and development of offspring. Lemurs in particular may be most sensitive to ecological stress, as Madagascar's environment is notably harsh and unpredictable. Several traits unique to lemurs (e.g., female dominance, flexible activity patterns, small group sizes), when compared with other primates, are hypothesized to be adaptations to ecological stress, and conserve energy and maximize resources in a stressful environment. However, scant field research has been conducted to test this hypothesis. Very little is known about the stress response in natural habitats. Measures of cortisol, a hormone released in response to stress, can quantitatively assess stressors in wild animals, and do not require animal handling. Annual hormonal profiles will be constructed to identify ecological and reproductive correlates to cortisol excretion. Using the red-bellied lemur (Eulemur rubriventer) as a model, and cortisol as an indicator of stress, this study will investigate how food abundance, reproduction, and habitat quality interact in Ranomafana National Park, Madagascar. The following will be explored: (1) Are fluctuations in food abundance reflected in cortisol levels? (2) Are different reproductive stages reflected in cortisol levels? (3) Does synchronizing infant weaning with particular ecological events offset the costs of this activity? (4) Does habitat disturbance affect the duration and magnitude of the stress response to food abundance and reproduction?In addition to its relevance to understanding lemur evolution, this project will enable future comparisons with studies on other lemur species, which will help identify species more vulnerable to stress. Constructing hormonal profiles of Malagasy primates will also provide a basis for comparisons with primates from other regions which are not subject to Madagascar's unique environment. This study will continue to provide hands-on experience in fieldwork and data collection for Malagasy and non-Malagasy university students. Malagasy students will also receive academic and financial support for the completion of Master's degrees. Public lectures will facilitate interaction with local people, and collaboration will occur with faculty from the University of Antananarivo. Final reports will be filed with park agencies to contribute to conservation efforts in Madagascar and promote scientific collaboration with other researchers in the area.