Abstract Spatial synchrony—correlated abundance fluctuations among distinct populations—is associated with increased extinction risk but is not a component of widely-used extinction risk assessments (e.g., IUCN Red List, U.S. Fish and Wildlife Service's Species Status Assessment). Alongside traditional viability metrics (i.e., the number of populations, their spatial extent, the status of each population), consideration of spatial synchrony in these assessments may provide additional insight into extinction risk as well as the relative importance of intrinsic and extrinsic factors on population dynamics. We demonstrate a method for estimating abundance trends in populations of the endangered freshwater fish, the amber darter (Percina antesella), while simultaneously assessing empirical support for existence of spatial synchrony among its two populations in the Conasauga and Etowah rivers in Georgia, U.S.A. Our analysis was performed using multivariate autoregressive state-space (MARSS) models with annual sampling data from 1996 to 2018 at 16 sites distributed between the two rivers. Our results indicate that amber darter populations have declined substantially, with 9% annual losses in both the Conasauga and Etowah rivers, suggesting rangewide imperilment. Furthermore, model selection indicated little support for models with fully independent dynamics between rivers, which may compound overall extinction risk. This analysis demonstrates the utility of tools such as MARSS models for assessing spatial synchrony and long-term population trajectories of imperiled species, resulting in improved vulnerability assessments that do not assume independence among separate populations.

中文翻译：

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通过多变量分析将空间同步性纳入受威胁物种的状态评估

摘要 空间同步性——不同种群之间相关的丰度波动——与灭绝风险增加有关，但不是广泛使用的灭绝风险评估（例如，IUCN 红色名录、美国鱼类和野生动物管理局的物种状况评估）的组成部分。除了传统的生存能力指标（即种群数量、它们的空间范围、每个种群的状态），在这些评估中考虑空间同步性可以提供对灭绝风险的额外洞察以及内在和外在因素对种群的相对重要性动力学。我们展示了一种估计濒危淡水鱼琥珀鱼（Percina antesella）种群丰度趋势的方法，同时评估美国佐治亚州科纳索加河和埃托瓦河两个种群空间同步性存在的实证支持我们的分析是使用多元自回归状态空间 (MARSS) 模型进行的，其中包含 1996 年至 2018 年分布在 16 个地点的年度采样数据两条河流之间。我们的结果表明，琥珀镖种群数量大幅下降，科纳索加河和埃托瓦河的年损失率为 9%，表明存在范围广泛的危害。此外，模型选择表明对河流之间完全独立动态模型的支持很少，这可能会增加整体灭绝风险。该分析证明了 MARSS 模型等工具在评估濒危物种的空间同步性和长期种群轨迹方面的效用，