The impact of extreme weather in December to February 2014 on meta-population processes in European shags

许多气候模型预测极端天气事件的频率会增加。因此，了解极端天气对野生种群的影响是种群、进化和保护生态学的关键目标。短期影响包括高死亡率、身体状况丧失和爆发性运动，可能导致长期影响，如繁殖不良、缺失群体以及扩散或迁移增加。在元种群尺度上，一个地点的天气导致的死亡可能会对下游其他地方造成影响，特别是在部分迁徙系统中，一些个体在冬季远离其繁殖地，而另一些则留在那里。气候导致的死亡率和相关迁移的空间异质性可以极大地重塑元种群的范围和结构。这种人口统计机制和动态尤其具有挑战性，难以理解长寿的迁徙物种，它们的繁殖前生活史阶段较长，难以观察，而且冬季影响和随后繁殖的地点是分开的。然而，这些物种可能特别容易受到极端天气的影响，因为它们由于成熟延迟和繁殖速度缓慢而从高死亡率事件中恢复缓慢。了解极端天气对长寿命移动物种的影响至关重要，因为许多物种具有高度的保护价值。为了满足决策者的需要，必须了解这种影响并将其纳入人口模型，以便为目前正在进行的政策决定提供信息。英国最近的严冬天气创造了一个紧迫而宝贵的机会来量化这种严重扰动的人口影响，使用部分迁移的欧洲长尾长尾雀（Phalacrocorax aristotelis），这已经是申请人领导的一项长期、全年人口研究的重点。长尾海鸟是一种寿命长，部分迁徙的沿海海鸟，在极端的冬季天气中死亡率很高。在过去的20年里，英国东北部的元种群数量减少了50%，我们收到了许多报告，在最近的风暴之后，典型的冬季地点出现了死亡和缺席，这意味着对元种群的严重干扰无疑已经发生。由于我们最近的工作，我们掌握了在最近的恶劣天气之前和迄今为止整个风暴期间的元种群人口统计（繁殖成功，生存，分散，迁移）和分布的全面数据。因此，我们有一个独特的和非常强大的基线数据集。现在迫切需要的是在2014年繁殖季节和繁殖后迁移期间有针对性地收集数据，以量化生存、繁殖成功、扩散或迁移的空间异质性在多大程度上驱动了跨季节人口对扰动的响应。我们将回答三个具体问题：a)天气导致的死亡率的空间格局如何影响元种群结构？b)对存活个体繁殖成功的下游影响是什么？c)对扩散和迁移的下游影响是什么？由于油泥受欧盟法律保护，可能面临海洋可再生能源开发的风险，因此迫切需要提供最新证据，为当前正在进行的政策决策提供信息。元人口的规模、分布和人口统计无疑已经发生了重大变化，这意味着现有的知识和人口模型已经过时。因此，我们的第四个项目目标是立即进行数据分析，并提供迫切需要的最新人口模型，以便为有效的海洋空间规划提供信息。

Many climate models predict increased frequency of extreme weather events. Understanding the impacts of extreme weather on wild populations is therefore a critical aim in population, evolutionary and conservation ecology. Short-term impacts include high mortality, lost body condition and eruptive movements, potentially leading to longer-term effects such as poor breeding, missing cohorts and increased dispersal or migration. At the meta-population scale, weather-induced mortality in one location may cause downstream impacts elsewhere, especially in partially migratory systems where some individuals winter away from their breeding location while others remain resident. Spatial heterogeneity in weather-induced mortality and associated movements could then substantially reshape meta-population range and structure. Such demographic mechanisms and dynamics are particularly challenging to understand in long-lived, migratory species with protracted pre-breeding life-history stages that are hard to observe, and where locations of winter impacts and subsequent reproduction are separated. Yet such species may be particularly vulnerable to extreme weather since they recover slowly from high mortality events due to delayed maturity and slow reproductive rates. Understanding the impacts of extreme weather on long-lived mobile species is critically important since many are of high conservation concern. To fulfil the needs of policy makers, it is imperative that such impacts are understood and incorporated into population models used to inform currently ongoing policy decisions. The UK's recent severe winter weather has created an urgent and valuable opportunity to quantify the demographic effects of this severe perturbation, using a partially migratory meta-population of European shags Phalacrocorax aristotelis that is already the focus of a long-term, year-round demographic study led by the applicants. Shags are long-lived, partially migratory coastal seabirds that experience high mortality during extreme winter weather. The north-east UK meta-population has declined by 50% during the last 20 years, and we have received numerous reports of dead shags and absences from typical winter locations following recent storms, meaning that a severe perturbation to the meta-population has doubtless occurred. Due to our recent work, we possess comprehensive data on meta-population demography (breeding success, survival, dispersal, migration) and distribution both before the recent severe weather and also throughout the storms to date. We therefore have a unique and extremely powerful baseline dataset. What is now urgently required is targeted data collection during the 2014 breeding season and post-breeding migration to quantify the degree to which cross-season demographic responses to perturbation are driven by spatial heterogeneity in survival, breeding success, dispersal or migration. We will answer three specific questions a) How did the spatial pattern of weather-induced mortality affect meta-population structure?; b) What are the downstream effects on breeding success of surviving individuals?; c) What are the downstream effects on dispersal and migration? Since shags are protected under EU law and potentially at risk from marine renewables developments, there is also a specific urgent need to provide updated evidence to inform currently ongoing policy decisions. Meta-population size, distribution and demography have doubtless been majorly reshaped, meaning that existing knowledge and population models are obsolete. Our fourth project objective is therefore to undertake immediate data analysis and provide the updated population models that are imminently required to inform effective marine spatial planning.