Eco-physiology of a socially flexible mammals living in a semi desert.

了解进化的内分泌机制如何使动物在不断变化的自然环境中做出适应性行为是拟议项目的主要目标。重点将放在调节新陈代谢(睾酮和皮质酮)、生殖(睾酮和雌激素受体α)和渗透调节(精氨酸加压素)的生理机制上。我将研究这些生理过程如何对环境变化做出反应，这些荷尔蒙分泌的变化如何调节社会行为，以及由此产生的健康后果。我将对同一种群中社会行为不同的同一物种的个体进行种内比较。我研究的物种是来自南非的条纹老鼠(Rhabdomys Umilio)，它是一种生活在潮湿和干旱栖息地的多面手。条纹老鼠表现出很高的社会灵活性：它们可以独自生活，也可以在大家庭中生活。我的研究人群生活在干旱的环境中，每年的旱季有明显的差异。首先，我将对自由生活的个体进行生理测量。测量荷尔蒙水平的样本将提供7年(2008-2014年)，在此期间，旱季的降雨量有明显的变化。我将把这些生理测量与食物和水的供应以及社会行为联系起来。我将进一步测试这一假设，即高水平的新陈代谢激素在旱季降雨量大的年份会带来健身益处，但在旱季明显的年份会降低存活率。这样的观察可能解释了种群内变异的维持。实验上，我会在旱季提供水，以测试对新陈代谢、精氨酸加压素水平和社会行为的影响。其次，在圈养和野外条件下，我将通过使用激素注入和拮抗剂来实验诱导在标准化条件下观察到的生理变化。我将测量生理参数和社会行为的变化。第三，我将研究环境引起的激素水平变化如何影响大脑功能，特别是精氨酸加压素的产生和雌激素受体α的表达，这是已知的影响社会行为的因素。拟议的项目将整合行为学、生态学和生理学的研究，将最终研究和近期研究结合起来，以了解社会行为的适应性改变。此外，我们还将深入了解同样出现在潮湿栖息地的物种如何在生理和行为上对干旱做出反应，干旱很可能在未来因气候变化而变得更加频繁。

Understanding how evolved endocrine mechanisms allow animals to behave adaptively in their changing natural environment is the main goal of the proposed project. The focus will be on physiological mechanisms regulating metabolism (testosterone and corticosterone), reproduction (testosterone and estrogen receptor α), and osmoregulation (arginine vasopressin). I will study how these physiological processes respond to environmental changes, how these changes in hormone secretion regulate social behavior, and the resulting fitness consequences. I will make intraspecific comparisons between individuals of one species within one population differing in social behavior. My study species, the striped mouse (Rhabdomys pumilio) from South Africa, is a generalist living in moist and arid habitats. Striped mice show high social flexibility: they can live solitarily or in extended family groups. My study population lives in an arid environment with pronounced differences in the annual dry season. First, I will take physiological measurements from free living individuals. Samples for measuring hormone levels will be available for 7 years (2008 – 2014), during which time there has been pronounced variation in the amount of rain during the dry seasons. I will correlate these physiological measurements with food and water availability and social behavior. I will further test the hypothesis that high levels of metabolic hormones lead to fitness benefits in years with significant rainfall during the dry season but to reduced survival in years with pronounced dry seasons. Such observations may explain the maintenance of variation within the population. Experimentally, I will provide water during the dry season to test for an influence on metabolism, arginine vasopressin levels and social behavior. Second, in captivity and in the field I will experimentally induce the observed physiological changes under standardized conditions by using hormone implants as well as antagonists. I will measure changes in physiological parameters and in social behavior. Third, I will study how environmentally induced variation in hormone levels influence brain function, especially arginine vasopressin production and the expression of estrogen receptor α, factors known to influence social behavior. The proposed project will integrate studies on behavior, ecology and physiology, combining both ultimate and proximate research to understand adaptive modification of social behavior. Additionally, we will gain insight into how a species that also occurs in moist habitats reacts physiologically and behaviorally to droughts, which are likely to become more frequent in the future as a consequence of climate change.