Using population synchrony to target conservation action

许多广布物种的迅速减少正在挑战传统的保护方法，迫切需要新的战略。识别和扭转特定环境驱动因素的影响的传统方法对广泛分布的物种很少可行，因为广泛的环境变化可能会导致物种范围内的种群数量下降。相反，我们需要a)确定通过提高生产率和/或存活率实现复苏的可行途径，以及b)将资金和保护行动的目标对准人口率较低且可以提高的地区和/或时间段。然而，这种方法的有效性将取决于不同物种范围内人口比率变化的规模和一致性。人口学上一致的空间差异(例如，生产力在一些地点总是高，在另一些地点总是低)将促进有针对性的长期保护行动(例如，通过生境管理)，以增加高生产率地点的频率。然而，人口比率的年度变化可能意味着，有针对性的保护行动最好在特定的年份进行(例如，通过提供食物或管理捕食者)。这种空间和时间变化通过同步性测量来捕捉，同步性是人口和社区动态的基本特征。在这项研究中，我们利用欧洲各地繁殖鸟类的数量、人口比率和相关环境条件的同步性，来改变人们对如何应对广泛物种减少的理解。同步性可以被定义为，例如，跨站点存在的个体数量的相关波动。同步性可以是相对局部的(通常反映当地的栖息地条件和社区相互作用)，也可以运行在数百公里以上(通常反映气候条件)。同步性也可以随着物种的范围和时间的不同而变化。我们将利用这一“同步性地理”和其中的任何时间变化来检验同步性的空间和时间模式是否反映了人口率(生产力和存活率)和相关环境条件的相同模式，以及它们对于具有相似特征的物种是否一致。各社区在数量、比率和环境条件方面的同步性之间的强烈联系将提供打破这些模式的平台，使我们能够确定保护行动的关键地点，并在时间上交付所需行动，以减少人口比率和丰富度较低的条件的频率。量化时空同步性变化的机会很少，因为它们需要广泛空间尺度上的长期数据。鸟类种群是很好的模型系统，因为公民科学计划可以在必要的范围内产生标准化的丰度和人口统计指标。使用欧洲鸟类调查数据来探索同步性的人口驱动因素也可以为生态进步提供当前和关键的保护应用。在整个欧洲，许多广为传播的鸟类物种在近几十年来严重减少，其中农田鸟类、非洲-欧亚候鸟和特殊物种的减少最为明显。迫切需要能够解决这些下降的行动，但仍然难以捉摸。我们将使用从18个国家16500多个地点收集的80个物种的调查数据来量化计数和速率同步的地理位置是否1)物种内相似；2)随时间变化；3)物种共享生态特征。将同步性的这三个关键特征与环境变量中的同等模式联系起来，将有助于确定影响人口比率的环境条件、人口比率的运行规模，从而确定最有可能实现人口恢复的保护行动的类型和规模。

Rapid declines in many widespread species are challenging traditional conservation approaches, and new strategies are urgently needed. Conventional approaches of identifying and reversing the effects of specific environmental drivers are rarely feasible for widespread species, because a broad range of environmental changes can be contributing to population declines across species' ranges. Instead we need to a) identify achievable routes to recovery by boosting productivity and/or survival and b) target funding and conservation actions to locations and/or time periods in which demographic rates are low and could be boosted. However, the effectiveness of such an approach will depend on the scale and consistency of variation in demographic rates across species' ranges. Consistent spatial variation in demography (eg productivity always high in some sites and low in others) would facilitate targeted long-term conservation action (eg through habitat management) to increase the frequency of sites with high productivity. However, annual variation in demographic rates could mean that targeted conservation actions are best delivered in specific years (eg by providing food or managing predators). This spatial and temporal variation is captured by measures of synchrony, a fundamental feature of population and community dynamics. In this study, we exploit synchrony in counts, demographic rates and associated environmental conditions for breeding birds across Europe, to deliver a step-change in understanding of how to address declines in widespread species. Synchrony can be defined as the correlated fluctuation in, for example, the number of individuals present across sites. Synchrony can be relatively localised (often reflecting local habitat conditions and community interactions), or it can operate over hundreds of kilometres (often reflecting climatic conditions). Synchrony can also vary across species' ranges and through time. We will exploit this 'geography of synchrony' and any temporal changes in it to examine whether spatial and temporal patterns in synchrony reflect equivalent patterns in demographic rates (productivity and survival) and associated environmental conditions, and if they are consistent for species with similar characteristics. Strong links between synchrony in counts, rates and environmental conditions across communities would provide the platform for disrupting these patterns, enabling us to identify key sites for conservation actions and the temporal delivery of actions needed to reduce the frequency of conditions with low demographic rates and abundance. Opportunities to quantify spatio-temporal variation in synchrony are rare because they require long-term data across broad spatial scales. Bird populations are excellent model systems because citizen science schemes exist that generate standardised measures of abundance and demography over requisite scales. Using European bird survey data to explore the demographic drivers of synchrony can also provide a current and critical conservation application of the ecological advances delivered. Across Europe, many widespread bird species have declined severely in recent decades, with declines most apparent amongst farmland birds, African-Eurasian migrants, and specialist species. Actions capable of addressing these declines are urgently needed but have remained elusive. We will use survey data from 80 species, collected from over 16500 sites across 18 countries to quantify whether the geographies of count and rate synchrony are 1) similar within species; 2) changing over time and 3) more similar for species sharing ecological traits. Linking these three key features of synchrony with equivalent patterns in environmental variables will allow identification of the environmental conditions influencing demographic rates, the scales at which they are operating, and thus the types and scales of conservation actions most likely to achieve population recovery.