Abstract Annual Finnish breeding duck surveys over the last 30 years show declining abundance among several species and greater declines on eutrophic waters than oligotrophic lakes. It has been suggested that habitat-related differences in the rate of increase in predation pressure is a potential explanation for contrasting duck population trajectories between habitats. We assessed potential duck nest predation risk and predator presence in various duck breeding habitats in Finland and Denmark by monitoring 333 artificial duck nests with wildlife cameras during 2017–2019. Predation rates differed between landscapes and habitats: nest predation rate and predator diversity were lowest in forested and highest in agricultural landscapes. Forest nests further from water bodies survived better than nests around shorelines of permanent lakes. Of the 16 different predator species detected, the most common were Eurasian magpie (Picapica), hooded crow (Corvus corone) and raccoon dog (Nyctereutes procyonoides). While predation by specific native predator species was typically associated with particular habitats and landscapes, the alien raccoon dog appeared to be a true habitat generalist, ubiquitous and common across all habitats and landscapes. Based on these results, the higher duck nest predation pressure along shorelines, especially in agricultural landscape lakes, due to increased diversity and abundance within the predator community, may contribute to the declining population trends of ducks.

中文翻译：

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景观和栖息地影响本地物种捕食人工鸭巢的频率，但不会影响外来捕食者

摘要 过去 30 年的年度芬兰种鸭调查显示，几个物种的丰度下降，富营养化水域的下降幅度大于贫营养湖泊。有人提出，与栖息地相关的捕食压力增加率的差异是栖息地之间对比鸭种群轨迹的潜在解释。我们通过在 2017-2019 年期间使用野生动物相机监测 333 个人造鸭巢，评估了芬兰和丹麦各种鸭子繁殖栖息地的潜在鸭巢捕食风险和捕食者的存在。不同景观和栖息地的捕食率不同：巢穴捕食率和捕食者多样性在森林中最低，在农业景观中最高。远离水体的森林巢穴比永久性湖泊海岸线周围的巢穴存活得更好。在检测到的 16 种不同的捕食者物种中，最常见的是欧亚喜鹊 (Picapica)、乌鸦 (Corvus corone) 和浣熊 (Nyctereutes procyonoides)。虽然特定本地捕食者物种的捕食通常与特定的栖息地和景观有关，但外星貉似乎是真正的栖息地通才，在所有栖息地和景观中无处不在和普遍。基于这些结果，由于捕食者群落的多样性和丰度增加，沿海岸线的鸭巢捕食压力较高，尤其是在农业景观湖泊中，可能导致鸭子种群数量下降。虽然特定本地捕食者物种的捕食通常与特定的栖息地和景观有关，但外星貉似乎是真正的栖息地通才，在所有栖息地和景观中无处不在和普遍。基于这些结果，由于捕食者群落内的多样性和丰度增加，沿海岸线的鸭巢捕食压力较高，尤其是在农业景观湖泊中，可能导致鸭子种群的下降趋势。虽然特定本地捕食者物种的捕食通常与特定的栖息地和景观有关，但外星貉似乎是真正的栖息地通才，在所有栖息地和景观中无处不在和普遍。基于这些结果，由于捕食者群落内的多样性和丰度增加，沿海岸线的鸭巢捕食压力较高，尤其是在农业景观湖泊中，可能导致鸭子种群的下降趋势。