Ecology and evolutionary biology of stress in birds

我的总体目标是从生活史的角度研究鸟类应激的原因和后果。压力在动物的生活中无处不在，对它们的健康产生普遍影响。个体如何感知、反应和应对压力源对于动物的生理、行为和生态至关重要。生理机制如何调节动物与其环境之间的关系有助于我们更好地理解生活史的多样化，即​​优化有限资源配置的策略。当动物面临压力源时，生活史权衡尤其值得注意，因为它们必须在处理压力源和维持状况的竞争需求之间分配有限的资源（例如能量、类胡萝卜素等营养素、免疫功能）。可检验的假设是，最佳策略应根据个体状况的成本和压力源的性质而变化。我使用野生和圈养鸟类来研究繁殖努力、性装饰以及鸟类如何应对人为干扰的压力。虽然我会通过多种方式评估状况、健康和压力，但我将特别使用我开发的一种新技术来量化羽毛中的皮质酮（应激激素），从而可以对应激生理学进行长期评估（数天到数月）。我将操纵寄生虫负载、饮食、食物供应和环境温度等压力源，以研究压力在调节父母努力与条件、后代数量与质量等权衡中的作用。同样，我将通过实验研究皮质酮和睾酮如何调节类胡萝卜素用于性装饰品着色与免疫功能之间的权衡。我还通过植入物直接控制激素水平，并从药理学角度测试下丘脑-垂体-肾上腺（压力）轴各组成部分的能力，这可能有助于解释物种内部和物种之间对压力的反应和后果的巨大差异。我的方法的新颖性将把压力研究领域引向新的方向，对基础科学、兽医、畜牧业、保护生物学和野生动物管理产生影响。

My general objective is to study causes and consequences of stress in birds from a life history perspective. Stress is ubiquitous in the lives of animals with pervasive consequences to their well being. How individuals perceive, respond to and cope with stressors is crucial to an animal's physiology, behaviour and ecology. How physiological mechanisms mediate the relationship between the animal and its environment help us better understand the diversification of life histories, i.e., strategies to optimize the allocation of limited resources. Life history trade offs are particularly notable when animals are exposed to stressors for they must allocate limited resources (e.g. energy, nutrients such as carotenoids, immune function) between the competing demands of dealing with the stressor and maintaining condition. The testable hypothesis is that the optimal strategy should vary with the cost to individual condition and nature of the stressor. I use both wild and captive birds to study stress in the context of reproductive effort, sexual ornamentation and how birds deal with anthropogenic disturbances. Although I will assess condition, health and stress in many ways, I will especially use a novel technique I developed for quantifying corticosterone (stress hormone) in feathers that allows for a long-term evaluation (days to months) of stress physiology. I will manipulate such stressors as parasite loads, diet, food supply and environmental temperature to investigate the role of stress in mediating such trade offs as parental effort vs condition, and number vs quality of offspring. Similarly, I will investigate experimentally how corticosterone and testosterone mediate trade offs between the use of carotenoids for coloration of sexual ornaments vs. immune function. I also directly manipulate hormone levels with implants, and pharmacologically test the capacity of components of the hypothalamic-pituitary-adrenal (stress) axis that may help explain the great variation within and among species in their response to, and consequences of, stress. The novelty of my approach will take the field of stress research in new directions, with impacts in basic science, veterinary medicine, animal husbandry, conservation biology and wildlife management.