Population dynamics and conservation of animals in seasonal environments

从北极到热带生态系统，几乎所有的生物都经历了某种形式的季节性‘，其特点是资源在年度周期中波动。每年的资源波动通常导致相对较长的时间段，其中动物只致力于获取生存资源(即非繁殖期)，其间穿插着较短的时间段(S)，在较短的时间段内，重点转移到繁殖(即繁殖期)。繁殖季节和非繁殖季节之间的这种交替可能会对个体健康和种群动态产生重要影响，但在我们分解种群增长驱动因素和识别哪个季节正在推动种群下降的能力方面，这构成了一个主要障碍。这主要是因为绝大多数野外研究仍然集中在一年周期的一个阶段(通常是繁殖)。 在接下来的5年里，我建议采取多层次的方法来解决我的长期目标，即了解常住人口和迁徙人口如何应对环境变化。我的前两个目标集中在使用长期数据集(30年)，以了解整个年度周期中的事件如何导致人口增长率的年度变化。目的(1)研究衰退的北栖候鸟加拿大灰鸦(Perisoreus Canandsis)的遗传效应和气候变化。目的(2)研究密度和气候在多个季节的变化如何限制和调节候鸟--草原麻雀(Passerculus Sandwichensis)。我的第三个目标(3)是使用我们现在已经建立起来的实验实验室系统(黑腹果蝇的季节性种群)，结合来自野生种群的数据，检查物种种群计数中是否存在特定季节的信号，这些信号可以表明种群数量的下降是繁殖地还是非繁殖地发生的结果。 我建议的工作将新兴概念(季节性相互作用、完整的年度周期模型)与创新的数学模型(IPM和SEM)以及最先进的实地跟踪方法(ICARUS、MOTUS)结合在一起，明确地设计用于测试环境变化导致的人口下降的原因机制。通过将我们新的实验室系统与我们的野生系统和公民科学数据的预测模型相结合，我们还探索了一条新的研究途径，为确定哪里应该最有效地分配保护资源提供了希望。我的研究不仅将为我们的焦点生物体带来有价值的见解，还将提供基本的例子，说明如何将季节性纳入其中，对于理解推动人口增长的机制至关重要。

From Arctic to tropical ecosystems, virtually all organisms experience some form of seasonality' that is characterized by resource fluctuations over the course of an annual cycle. Annual resource fluctuations typically result in relatively long periods in which animals are devoted only to acquiring resources to survive (i.e. the non-breeding period) interspersed with a shorter period(s) where to focus shifts to reproduction (i.e. the breeding period). This alternation between breeding and nonbreeding seasons can have important consequences for individual fitness and population dynamics but has posed a major barrier in our ability to decompose the drivers of population growth and identify which season is driving declines. The primary reason for this is because the vast majority of studies in the wild still focus on a single period of the annual cycle (usually breeding). Over the next 5 years, I propose to take a multi-tiered approach to address my long-term goal of understanding how resident and migratory populations respond to environmental change. My first two objectives focus on using long-term datasets (30+ yrs) to understand how events throughout the annual cycle contribute to annual variation in population growth rates. Objective (1) focuses on carry-over effects and climate change in a declining boreal resident bird, the gray jay (Perisoreus canadensis). Objective (2) focuses on how variation in density and climate in multiple seasons act to limit and regulate a migratory bird, the Savannah sparrow (Passerculus sandwichensis). My third objective (3) is to use our now well-established experimental lab system (seasonal populations of Drosophila melanogaster), in conjunction with data from wild populations, to examine whether there are season-specific signals in species population counts that can indicate if population declines are a result of what is occuring on the breeding or non-breeding grounds. My proposed work combines emerging concepts (seasonal interactions, full annual cycle models) with innovative mathematical models (IPM & SEM) and state-of-the-art field tracking methods (ICARUS, Motus) and is explicitly designed to test causal mechanisms underlying population declines caused by environmental change. By combining our novel laboratory system with predictive models from our wild systems and citizen science data, we also explore a new avenue of research that offers promise for identifying where conservation resources should be most effectively allocated. My research will not only lead to valuable insights into our focal organisms but also provide fundamental examples of how incorporating seasonality is critical for understanding the mechanisms driving population growth.