Although invasive non-native species can adversely affect biodiversity in many ways, predation of native species by non-native species on islands can be severely damaging. Results of numerous studies document non-native birds preying on birds on islands, but our understanding of the number and type of species affected has been limited by the lack of a global review of these impacts. I identified the non-native bird species that have been recorded preying on birds, the locations where this predation occurred, and the bird species affected. Because the impacts of non-native birds can be particularly severe on small islands, I then identified the islands <500 km² around the world that are occupied by predatory non-native birds. By taking into account their life-history traits and predation history, I also identified the near-threatened and threatened bird species on these islands that they may prey on. The results indicated that predation by non-native birds was primarily a concern for threatened bird conservation on small islands; almost all predation impacts (91%) on near-threatened and threatened birds were recorded on islands, and median island size was 106 km². I also found non-native bird predation was a poorly known and widespread potential threat to avian biodiversity; worldwide, 194 islands of <500 km² were occupied by predatory non-native birds, but information on their impacts was unavailable for most of these islands. On them, where the impacts of non-native species can be severe, non-native birds may be preying on approximately 6% of the world's near-threatened and threatened bird species. Four non-native bird species I identified have been successfully eradicated from islands. If they were eradicated from the small islands they occupy, 70% of the near-threatened and threatened bird species I identified would no longer be affected by nest predation by non-native birds on small islands.

中文翻译：

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量化小岛上非本地鸟类捕食对本地鸟类的全球威胁

尽管入侵的非本地物种可以在许多方面对生物多样性产生不利影响，但非本地物种在岛屿上捕食本地物种可能会造成严重破坏。大量研究的结果记录了非本地鸟类捕食岛屿上的鸟类，但由于缺乏对这些影响的全球审查​​，我们对受影响物种的数量和类型的了解有限。我确定了记录捕食鸟类的非本地鸟类物种、发生这种捕食的地点以及受影响的鸟类物种。由于非本地鸟类对小岛屿的影响可能特别严重，因此我确定了小于 500 km ²的岛屿世界各地被掠食性非本土鸟类占据。通过考虑它们的生活史特征和捕食历史，我还确定了这些岛屿上它们可能捕食的近乎濒危和受威胁的鸟类。结果表明，非本地鸟类的捕食主要是小岛上受威胁鸟类保护的一个问题；几乎所有对近危和受威胁鸟类的捕食影响 (91%) 都记录在岛屿上，岛屿面积中位数为 106 公里²。我还发现非本地鸟类捕食是对鸟类生物多样性的一种鲜为人知且广泛存在的潜在威胁；世界范围内，194 个岛屿<500 km ²被掠食性的非本地鸟类占据，但这些岛屿中的大多数都无法获得有关其影响的信息。在非本地物种的影响可能很严重的地方，非本地鸟类可能正在捕食世界上大约 6% 的近乎濒危和受威胁的鸟类。我确定的四种非本地鸟类已从岛屿上成功根除。如果它们从它们占据的小岛上被根除，我确定的 70% 的濒危和受威胁的鸟类将不再受到小岛上非本地鸟类的巢穴捕食的影响。