Data from: Landscape genetics of the nonnative red fox of California

Invasive mammalian carnivores contribute disproportionately to declines in global biodiversity. In California, nonnative red foxes (Vulpes vulpes) have significantly impacted endangered ground-nesting birds and native canids. These foxes derive primarily from captive-reared animals associated with the fur-farming industry. Over the past five decades, the cumulative area occupied by nonnative red fox increased to cover much of central and southern California. We used a landscape-genetic approach involving mitochondrial DNA (mtDNA) sequences and 13 microsatellites of 402 nonnative red foxes removed in predator control programs to investigate source populations, contemporary connectivity, and metapopulation dynamics. Both markers indicated high population structuring consistent with origins from multiple introductions and low subsequent gene flow. Landscape-genetic modeling indicated that population connectivity was especially low among coastal sampling sites surrounded by mountainous wildlands but somewhat higher through topographically flat, urban and agricultural landscapes. The genetic composition of populations tended to be stable for multiple generations, indicating a degree of demographic resilience to predator removal programs. However, in two sites where intensive predator control reduced fox abundance, we observed increases in immigration, suggesting potential for recolonization to counter eradication attempts. These findings, along with continued genetic monitoring, can help guide localized management of foxes by identifying points of introductions and routes of spread and evaluating the relative importance of reproduction and immigration in maintaining populations. More generally, the study illustrates the utility of a landscape-genetic approach for understanding invasion dynamics and metapopulation structure of one of the world's most destructive invasive mammals, the red fox.

入侵性哺乳类食肉动物对全球生物多样性衰退的影响不成比例地显著。在加利福尼亚州，外来红狐（Vulpes vulpes）已对濒危地面筑巢鸟类与本土犬科动物造成显著负面影响。此类红狐主要源自与毛皮养殖业相关的人工繁育个体。过去五十年来，外来红狐的累计分布范围已扩张至加利福尼亚州中部与南部的大部分区域。本研究针对402只在捕食者防控项目中被移除的外来红狐，采用结合线粒体DNA（mtDNA）序列与13个微卫星标记的景观遗传学分析方法，对其源种群、当前种群连通性及集合种群动态展开探究。两类分子标记均显示出较高的种群遗传结构，这与多次引种事件以及后续极低的基因流水平相符。景观遗传学模型结果表明，被多山野生区域环绕的沿海采样点间种群连通性尤其低下，而在地形平坦的城市与农业景观中，种群连通性则相对更高。红狐种群的遗传组成在多代周期内整体趋于稳定，这表明其对捕食者移除项目具备一定的种群动态韧性。但在两个实施高强度捕食者防控、致使红狐种群数量下降的研究区域中，我们观测到移民率上升的现象，这显示红狐具备重新定植的潜力，可抵消根除行动的效果。结合持续开展的遗传监测，本研究结果可通过明确红狐的引种点位与扩散路径，评估繁殖与移民在维持种群存续中的相对重要性，进而为红狐的本地化管理提供指导。从更广泛的视角来看，本研究验证了景观遗传学方法在解析全球极具破坏性的入侵哺乳类动物之一——红狐的入侵动态与集合种群结构方面的应用价值。