Using Hormones to Explore Adaptation and Constraint in a Male Bird

凯特森97-28384 这项研究的主要目的是探索睾丸激素如何影响雄性鸟类的行为和生理，包括对雄性鸟类在野外生存和繁殖能力的影响。这些结果将增强对适应和约束的理解，并帮助我们预测动物如何在进化上对不断变化的环境做出反应。 主要研究者（PI）用缓释睾酮（T）植入物治疗自由生活的雄性黑眼容科斯（Junco hyemalis，俗称雪鸟）。对照组接受空植入物。PI测量一系列表型性状，并比较实验表型与对照表型的适合度。只有考虑到整个阵列和实验诱导的变化对适应性的净效应，他们才有希望了解是什么维持了现有的和谐表型。 具体目标包括： 1.继续研究睾酮对雄性容科斯适合度相关性状的直接影响，包括a）对雏鸟的行为和B）非繁殖季节的行为和生理; 2.通过测量雄性T对雌性的行为和生理学（卵类固醇、后代的性别、可育时空间的利用）的影响来量化T对雄性的扩展表型的间接影响; 3.完成对已完成的10年人口研究的分析。

Ketterson 97-28384 The primary objective of this research is to explore how the hormone testosterone influences behavior and physiology in a male bird including any effects on a male's ability to survive and reproduce in the wild. The results will enhance understanding of adaptation and constraint and help us to predict how animals respond evolutionarily to changing environments. The Principal Investigators (PIs) treat free-living male dark-eyed juncos (Junco hyemalis, commonly known as the snowbird) with slow-release implants of testosterone (T). Controls receive empty implants. The PIs measure an array of phenotypic traits and compare fitness of the experimental phenotype with that of controls. Only by considering the whole array and the net effect of experimentally induced changes on fitness can they hope to understand what maintains existing harmonal phenotypes. Specific objectives include: 1. continued investigation of direct effects of testosterone on fitness-related traits in male juncos, including a) behavior towards nestlings and b) behavior and physiology during the non-breeding season; 2. quantification of indirect effects of T on the male's extended phenotype by measuring die impact of male T on the behavior and physiology of females (egg steroids, sex of offspring, use of space while fertile); 3. completion of analysis of an already completed l0-year demographic study.