Dissertation Research: Population Density, Social Behavior, and Physiological Stress in Lemur catta

人口密度的差异往往反映在社会行为中，但其途径和机制仍有待阐明，特别是在自然人口中。这项关于野生原猴种群的研究，利用内分泌反应来确定几种生态和社会应激源对依赖密度的行为、生理和繁殖成功变化的相对贡献。这项研究得益于独特的野外条件，在这种条件下，对六个习惯性灵长类种群进行了详细的种群密度梯度研究，并建立了研究方法，以获得关于生存、繁殖、觅食效率、攻击行为和应激反应水平的个体水平数据，这些数据是通过在没有干预的情况下采集排泄的类固醇样本来衡量的。在两年的时间里，大约80只动物的数据可以检验这样的假设，即食物稀缺、群体内冲突和群体间冲突在皮质醇水平上有不同程度的反映，这种应激反应的大小预测个体健康和短期繁殖成功。

Differences in population density are often reflected in social behavior yet the pathways and mechanisms remain to be elucidated, particularly in natural populations. This research on a wild population of the prosimian, Lemur catta, uses endocrine responses to identify the relative contributions of several ecological and social stressors to density-dependent changes in behavior, physiology, and reproductive success. The study benefits from unique field conditions in which six habituated primate groups are studied across a well-documented population-density gradient, and research methods have been established for obtaining individual-level data on survival, reproduction, foraging efficiency, aggressive behavior, and levels of stress response as measured by excreted steroids sampled without intervention. The data for approximately 80 animals over a two-year period permit testing the hypotheses that food scarcity, conflicts within groups, and conflicts between groups are reflected to varying degrees in cortisol levels and that the magnitude of this stress response predicts individual health and short-term reproductive success.