Collaborative Research: Life History Tradeoffs: An Integrative Approach

种群生物学的一个目标是了解环境如何导致物种之间的差异；另一个是探索控制个体物种生活史特征的行为和生理机制。这项研究旨在通过研究激素如何塑造和指导一种名为黑眼junco的小鸟的生活，为这一基础知识做出贡献。研究的重点是雄性和睾丸激素，众所周知，睾丸激素对动物的行为、生理和形态（形状和形态）有许多影响。这些影响包括睾酮对雄性亲代行为的抑制作用和对配偶吸引行为（如唱歌）的刺激作用。睾丸素还能降低对疾病的抵抗力。通过控制血液中睾酮的含量，并将治疗后的鸟与未治疗的对照组鸟的行为和生理进行比较，将检查引起的变化，并将其与适应性相关，如繁殖后代的能力、寿命和后代的存活率相关联。这些鸟将在野外进行研究，在那里可以监测它们的生存和繁殖后代的成功。通过追踪生理和行为偏离正常状态的动物的命运，这项研究将使人们对激素系统如何进化以及选择因素和有机体反应的平衡如何使特定动物物种在进化过程中“走上正轨”有更基本的了解。

One objective of population biology is to understand how the environment leads to differences among species; another is to explore the behavioral and physiological mechanisms that control life history traits of individual species. This research is designed to contribute to this basic knowledge by studying how hormones shape and direct the life of a small bird, the dark-eyed junco. The focus is on males and the hormone testosterone, which is known to have numerous effects on animal behavior, physiology, and morphology (shape and form). These effects include a suppressive effect of testosterone on male parental behavior and a stimulatory effect on behavior related to mate attraction, e.g. singing. Testosterone can also decrease resistance to disease. By manipulating the amount of testosterone in the blood and comparing the behavior and physiology of the treated birds to that of untreated, control birds, changes induced will be examined and related to correlates of fitness, such as ability to sire offspring, life span, and survival of offspring. The birds will be studied in the field where their survival and success in producing offspring can be monitored. By tracking the fates of animals whose physiology and behavior deviates from the normative state, the research will lead to a more fundamental understanding of how hormonal systems evolve and what balance of selective factors and organismal responses keeps a particular animal species "on track" over evolutionary time.