Physiology of Stress in Wild Animals

所有生物都面临着来自环境的有害刺激（如捕食者或风暴）。脊椎动物激活一套生理机制来保护自己免受这些刺激，统称为应激反应。应激反应的一个重要部分是糖皮质激素类固醇激素的释放，但即使经过60多年的压力研究，我们对糖皮质激素如何帮助野生动物生存仍然只有一个初步的了解。早期的研究表明，几种自由生活的鸟类通过全年不同的激素浓度来季节性地调节糖皮质激素的释放。该建议建立在这些结果的基础上，提出以下问题：为什么动物会季节性地调节糖皮质激素水平；有生理上的后果吗？它会影响他们对慢性压力的易感性吗？回答这些问题需要实验室和实地研究的综合方法，就像这里提出的那样。我们将捕获野生的自由生活的麻雀（Passer家麻雀），并测试糖皮质激素如何在一年中的不同时间帮助调节血糖和甘油三酯水平。我们预计葡萄糖和甘油三酯的调节将取决于糖皮质激素水平的季节性变化。我们还将把家雀带入实验室，测试它们对慢性压力的生理反应是否会随季节而变化。我们预计，慢性压力的负面影响的程度将取决于一年中的时间。这些结果将有助于确定野生动物应激时季节性糖皮质激素释放的生理后果，从而对我们对应激反应的生态有效性的基本知识产生深远的影响。这项研究也将为学生提供重要的训练。研究生和本科生都将在实验室和现场接触和学习许多重要的研究技能。这些发现对保护生物学、内分泌学和种群生物学等不同领域的研究人员都很有价值。

L. Michael RomeroPhysiology of Stress in Wild AnimalsProposal Number 0235044 All organisms are faced with noxious stimuli from the environment (such as predators or storms). Vertebrates activate a suite of physiological mechanisms to protect themselves from these stimuli, collectively called the stress response. A vital part of the stress response is the release of the glucocorticoid steroid hormones, but even after more than 60 years of studying stress we still have only a rudimentary idea of how glucocorticoids help wild animals survive. Earlier work indicated that several free-living bird species seasonally regulate glucocorticoid release by varying concentrations of the hormone throughout the year. This proposal builds upon these results to ask the following questions: why do animals seasonally regulate glucocorticoid levels; is there a physiological consequence; and does it affect their susceptibility to chronic stress? Answering these questions will require an integrated approach of both laboratory and field studies, such as the one proposed here. We will capture wild free-living house sparrows (Passer domesticus) and test how glucocorticoids help regulate blood glucose and triglyceride levels at different times of the year. We anticipate that glucose and triglyceride regulation will depend upon seasonal changes in glucocorticoid levels. We will also bring house sparrows into the laboratory to test whether physiological responses to chronic stress vary seasonally. We anticipate that the magnitude of the negative consequences of chronic stress will depend upon the time of year. These results will help define the physiological consequences of seasonal glucocorticoid release during stress in wild animals, thus having a far-reaching impact on our basic knowledge of the ecological validity of stress responses.This research will also provide important training for students. Both graduate and undergraduate students will be exposed to, and learn, many important research skills in both the laboratory and field. These findings will be valuable to researchers in diverse fields including Conservation Biology, Endocrinology, and Population Biology, just to mention a few.