Plant invasion: Another threat to the São Paulo Marsh Antwren (<i>Formicivora paludicola</i>), a species on the verge of extinction

During the past 100 years in densely populated south-eastern Brazil, wetlands have been severely transformed due to urbanization, agriculture and mining. The recently discovered São Paulo Marsh Antwren (Formicivora paludicola) is endemic to these wetlands, and is listed as “Critically Endangered” by the IUCN. The species is only found in an area of 1.42 km2, it has a sparse and fragmented distribution, low dispersal capacity, and has probably lost around 300 km2 of habitat in the past 100 years. Furthermore, very little is known about F. paludicola natural history, and so it is difficult to construct a robust conservation plan. Using Kernel home range estimations and the Adjusted-SD/Torus Shift test (a novel tool for animal-habitat association studies), we showed that the species avoids patches of the alien invasive ginger lily (Hedychium coronarium). Given the high density of their population (3.6 mature individuals/ha), F. paludicola could thrive in relatively small areas of suitable wetlands protected from human occupation and water contamination, however special attention should be paid to biological invasions, which may represent a serious threat to the remaining populations. Protecting a few small wetlands used by F. paludicola would be an important step towards general conservation and restoration of Atlantic Forest wetlands and its endemic endangered species.过去一个世纪以来，人口稠密的巴西东南部湿地因城市化、农业开垦与采矿活动遭到严重改造与破坏。此次新发现的圣保罗沼泽蚁鹩（Formicivora paludicola）为该类湿地特有物种，已被世界自然保护联盟（IUCN）列为“极危”等级。该物种仅分布于1.42平方公里的范围内，种群分布稀疏且碎片化，扩散能力低下，过去一个世纪间其栖息地已丧失约300平方公里。此外，学界对圣保罗沼泽蚁鹩的自然史所知甚少，因此难以制定严谨完善的保护方案。本研究通过核域家域估计法与调整SD/环面位移检验（一种用于动物-栖息地关联研究的新型工具）分析发现，该物种会避开外来入侵物种姜花（Hedychium coronarium）的分布斑块。鉴于其种群密度较高（3.6只成熟个体/公顷），圣保罗沼泽蚁鹩可在面积相对较小的适宜湿地中繁衍生存，只要该类湿地不受人类活动占用且未遭受水体污染；但需特别关注生物入侵问题，其或对现存种群构成严重威胁。保护圣保罗沼泽蚁鹩所依赖的小片湿地，将是大西洋森林湿地及其特有濒危物种整体保护与修复工作的重要一环。