Phenotypic flexibility, physiological tradeoffs and performance in wintering and migratory birds

这个项目的目的是了解面对高能量需求的动物，在受到身体设计和能量供应的限制的同时，如何调整它们的生理系统，以解决相互冲突的需求，并最大化地生存和繁殖。我们与两种经常遇到极端生理限制的鸟类合作，这两种鸟类可能会揭示这些调整的后果：一种是常驻的黑帽山雀，另一种是长距离迁徙的滨鸟，即红结。我们的三个短期目标是(A)调查鸟类在冬季和迁徙期间面临相互冲突的限制的生理权衡的长期后果，(B)量化生理特征的适应变化的速度和灵活性的范围，以便研究特征的灵活性如何限制生活史和(C)研究鸟类冷驯化的激素调节。结合圈养和自由生活条件下的实验研究，我们正在研究动物对环境变化的反应，从细胞水平到整个动物和种群。我的项目涉及两个当地项目(山雀)以及将在四个欧洲国家(红结、法国、荷兰、冰岛和挪威)进行的两个项目。我们将研究：(1)甲状腺激素在调节对寒冷和冬季的代谢反应中的作用；(2)冬季气候条件和能量消耗如何与栖息地质量相互作用，影响代谢表现、生理条件、生存和繁殖；(3)生理特性调节的幅度和速度如何影响面临消化和体温调节需求冲突的越冬结的存活；(4)调节的幅度和速度如何限制迁徙速度和个体条件在迁徙停留期间面临极端生理需求的结。我们的发现将具有重大意义，因为它们将提供对生态和生理限制之间相互作用的综合理解，从而塑造动物对环境的适应反应。结果将帮助我们了解生物体如何调整其生理以适应快速的环境变化和气候变化。

The aim of this program is to understand how animals facing high energy demands, while constrained by body design and energy supply, adjust their physiological systems to solve conflicting demands and maximize survival and reproduction. We work with two bird species that routinely encounter extreme physiological constraints likely to shed light on consequences of those adjustments: resident black-capped chickadees and a long-distance migratory shorebird, the red knot. Our three short-term objectives are (A) to investigate long-term consequences of physiological trade-offs in birds facing conflicting constraints during winter and migration, (B) to quantify the speed of adaptive change and range of flexibility in physiological traits in order to examine how trait flexibility may constrain life-histories and (C) to investigate hormonal regulation of cold acclimatization in birds. Combining experimental studies in captive and free-living conditions, we are studying animal's responses to environmental variations from the cell level to the whole animal and population. My program involves two local projects (chickadees) as well as two projects to be carried out in four European countries (red knots, France, Netherlands, Iceland and Norway). We will study: (1) the role of thyroid hormones in regulating the metabolic response to cold and winter improvement of cold endurance; (2) how winter climatic conditions and energy expenditure interact with habitat quality in influencing metabolic performance, physiological condition, survival and reproduction; (3) how amplitude and speed of physiological trait adjustments affect survival in wintering knots facing conflicting demands for digestion and thermoregulation and; (4) how amplitude and speed of adjustments might limit migration pace and individual condition in knots facing extreme physiological demands during migratory stopover. Our findings will be of major importance, as they will provide an integrated understanding of the interplay between ecological and physiological constraints in shaping animal's adaptive response to their environment. Results will help us understand how organisms adjust their physiology to rapid environmental alterations and climate change.