Invasive species have led to precipitous declines in biodiversity, especially in island systems. Brown (Rattus norvegicus) and black rats (R. rattus) are among the most invasive animals on the planet, with eradication being the primary tool for established island populations. The need for increased research for defining eradication units and monitoring outcomes has been highlighted as a means to maximize success. Haida Gwaii is an archipelago ~100 km off the northern coast of British Columbia, Canada, that hosts globally significant breeding populations of seabirds that are at risk due to invasive rats. Here, we paired sampling of brown (n = 287) and black (n = 291) rats across the Haida Gwaii archipelago with genotyping by sequencing (10,770–27,686 SNPs) to investigate patterns of population connectivity and infer levels/direction of gene flow among invasive rat populations in Haida Gwaii. We reconstructed three regional clusters for both species (north, central and south), with proximate populations within regions being largely more related than those that were more distant, consistent with predictions from island biogeography theory. Population assignment of recently detected individuals post‐eradication on Faraday, Murchison and the Bischof Islands revealed all were re‐invaders from Lyell Island, rather than being on‐island survivors. Based on these results, we identified six eradication units constituting single or clusters of islands that would limit the potential for reinvasion, some of which will need to be combined with biosecurity measures. Overall, our results highlight the importance of targeted research prior to conducting eradications and demonstrate a framework for applying population genomics for guiding invasive species management in island systems.

中文翻译：

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海达瓜伊群岛的黄鼠种群基因组学为指导入侵物种管理提供了框架。


入侵物种导致生物多样性急剧下降，特别是在岛屿系统中。褐家鼠 ( Rattusnorvegicus ) 和黑鼠 ( R.rattus ) 是地球上最具侵略性的动物，消灭它们是岛上现有种群的主要工具。人们强调需要加强研究来确定根除单位和监测结果，以此作为最大限度地取得成功的手段。海达瓜伊 (Haida Gwaii) 是距离加拿大不列颠哥伦比亚省北海岸约 100 公里的一个群岛，这里栖息着全球重要的海鸟繁殖种群，这些海鸟因老鼠入侵而面临危险。在这里，我们对海达瓜伊群岛的棕色 ( n = 287) 和黑色 ( n = 291) 老鼠进行配对采样，并通过测序进行基因分型 (10,770–27,686 个 SNP)，以研究群体连通性模式并推断群体之间基因流动的水平/方向。海达瓜伊的入侵鼠群。我们为这两个物种重建了三个区域集群（北部、中部和南部），区域内邻近种群的相关性很大程度上高于那些较远种群的相关性，这与岛屿生物地理学理论的预测一致。最近在法拉第、默奇森和比绍夫群岛上发现的灭绝后个体的种群分配显示，所有这些个体都是来自莱尔岛的重新入侵者，而不是岛上的幸存者。根据这些结果，我们确定了六个由单个岛屿或岛屿群组成的根除单位，这些单位将限制重新入侵的可能性，其中一些需要与生物安全措施相结合。 总体而言，我们的结果强调了在进行根除之前进行有针对性的研究的重要性，并展示了应用群体基因组学指导岛屿系统入侵物种管理的框架。