DISSERTATION RESEARCH: The Role of Breeding Hormones in Seasonal Interactions: How Do Birds Meet the Conflicting Demands of Breeding Preparation and Migration?

候鸟在相隔数千英里的地方完成生命周期的不同阶段。 一个阶段的条件可能会对后续阶段产生遗留影响。至关重要的是，研究人员研究环境因素如何在不同的年度阶段作为结转效应，以充分了解如何调节候鸟种群。 在美洲红尾椋鸟（Setophaga ruticilla），男性越冬的上级质量的栖息地更早到达繁殖地，并有更大的繁殖成功比那些在恶劣的栖息地越冬。 虽然这些季节性的相互作用是有据可查的，但其基本机制还没有得到很好的理解。 春季迁徙的能量需求可以通过从非繁殖状态过渡到繁殖状态的额外需求来复合。这项研究的重点是如何在牙买加，西印度群岛的这种过渡过程中，生态和内源性因素相互作用，如果激素通常与繁殖也可以帮助移民更早地到达繁殖地。 环境条件，能量储存，繁殖准备和迁移之间的关系将被检查。在春季出发前的一段时间里，雄性红尾椋鸟的特鲁姆将被操纵（与对照组相比，增强或抑制）。 羽毛和/或爪子中的稳定同位素特征将把越冬地面事件与到繁殖地的迁移距离联系起来。 将收集在牙买加越冬的其他新热带移栖物种的繁殖准备和迁移情况。这项研究将大大增加我们对越冬和繁殖事件如何联系在一起的理解，以及T在迁移背景下的作用。 它将帮助资源管理人员为移徙人口制定有效的管理计划。 该研究汇集了美国学术机构和牙买加的资源管理机构，并为对行为生态学，生态生理学和保护感兴趣的研究生和本科生提供了许多职业发展经验（实地观察，样本收集，激素操作，实验室技术）。

Migratory birds complete different stages of their life cycle in locations that can be thousands of miles apart. Conditions during one stage can impose carry-over effects on subsequent stages. It is critical that researchers examine how environmental factors act as carry-over effects across different annual stages in order to fully understand how migratory bird populations are regulated. In the American redstart (Setophaga ruticilla), males wintering in superior quality habitats arrive earlier at the breeding grounds and have greater breeding success than those wintering in poor habitats. While these seasonal interactions are well documented, the underlying mechanisms are not well understood. Energetic demands of spring migration can be compounded by the additional demands of transitioning from the non-breeding to breeding state. This study focuses on how ecological and endogenous factors interact during this transition in Jamaica, West Indies, and if hormones usually associated with breeding can also help migrants reach the breeding grounds earlier. Relationships among environmental conditions, energy stores, breeding preparation, and migration will be examined. Testosterone will be manipulated (enhanced or inhibited, compared to controls) in male redstarts during the period leading up to spring departure. Stable isotope signatures in feathers and/or claws will link wintering ground events with migration distance to the breeding grounds. Breeding readiness and migratory condition will be collected in other Neotropical migrant species wintering in Jamaica. This study will significantly add to our understanding of how wintering and breeding events are linked, and the role of T in a migration context. It will help resource managers develop effective management plans for migratory populations. The study brings together U.S. academic institutions and resource management agencies in Jamaica, and provides many career development experiences (field observations, sample collection, hormone manipulation, laboratory techniques) for graduate and undergraduate students interested in behavioral ecology, eco-physiology, and conservation.