Physiological links between individual quality and life-history strategies in Arctic birds

个体的素质及其周围环境应该塑造生命史策略。也许地球上最好的地方是极地环境，因为i)它们经历了巨大的环境质量变化，ii)许多物种依靠当地和储存的资源来促进繁殖，iii)短暂的繁殖季节对适应性有很强的影响。因此，个体必须平衡许多内部和外部的权衡，以优化繁殖决策。为了理解个体素质如何影响北极地区的健康，我研究了潜在的压力介导的生理机制，因为它们被预测直接将生物体与其环境联系起来。我关注的是个体生理素质、生殖决策和适应性之间的关系如何塑造了预计会影响适应性的关键生活史特征，如到达繁殖地的时间、繁殖的时间和后代的数量和质量。我主要关注的是质量介导的生理特征中的个体差异，这些生理特征被预测为驱动最优策略，因为它是自然选择的原材料。我研究的主要目标是：1)研究适应负荷（即个体质量）和环境压力（即气候变化）在调节生殖策略中的作用；2)研究驱动生殖决策的直接（即质量）和间接（即携带效应）质量介导机制。由于北极繁殖物种在越冬、迁徙和预繁殖过程中面临多重决策，因此我整合了多个生活史阶段，因为我们对跨阶段策略优化如何影响适应性知之甚少。我的研究优势来自于整合进化、生态学和生理学的概念和技术。我的研究不仅让进化生物学家了解了驱动生命史决定的机制，还为应用生态学家提供了潜在的机制，以理解为什么气候引起的繁殖时间的变化通过个体繁殖成功的变化影响了种群的持久性。

The quality of the individual and its surrounding environment should shape life-history strategies. Perhaps the best place on earth to examine the evolution of the trade-offs that drive these optimal strategies are Polar environments since i) they experience large variation in environmental quality, ii) many species rely on both local and stored resources to fuel reproduction, and iii) the short reproductive season has strong effects on fitness. As such, individuals must balance many internal and external trade-offs to optimize reproductive decisions. To understand how individual quality influences fitness in the Arctic, I examine underlying stress-mediated physiological mechanisms since they are predicted to directly connect the organism to its environment. I focus on how the relationship between individual physiological quality, reproductive decisions and fitness shape key life-history traits predicted to influence fitness such as the timing of arrival on breeding grounds, the timing of breeding and the quantity and quality of offspring. I concentrate primarily on individual variation in the quality-mediated physiological traits predicted to drive optimal strategies since it is the raw material that natural selection acts on. The main goals of my research are to 1) examine the role of allostatic load (i.e., individual quality) and environmental stress (i.e., climatic variability) in mediating reproductive strategies and 2) investigate direct (i.e., quality) and indirect (i.e., carry-over effects) quality-mediated mechanisms that drive reproductive decisions. Since Arctic-breeding species face multiple decisions during wintering, migration and pre-breeding, I integrate across multiple life-history stages as so little is known about how the optimization of strategies across stages influences fitness. The strength of my research comes from integrating concepts and techniques from Evolution, Ecology and Physiology. My research not only informs evolutionary biologists about the mechanisms driving life-history decisions, it also provides applied ecologists with the underlying mechanisms to understand why climate-induced changes in the timing of reproduction affect population persistence through changes in individual reproductive success.