Data from: Nest predation in New Zealand songbirds: exotic predators, introduced prey and long-term changes in predation risk

Predation is a major factor in ecology, evolution and conservation and thus its understanding is essential for insights into ecological processes and management of endangered populations of prey. Here we conducted a spatially (main island through to offshore islets) and temporally (1938-2005) extensive meta-analysis of published nest predation rates in New Zealand songbirds. We obtained information on nest predation rates from 79 populations (n = 4838 nests) of 26 species of songbirds belonging to 17 families. Nest predation rates increased from southwest to northeast and also across the last 60 years (by 15-25 percentage points in both cases). We identified a major impact of exotic mammalian predators. Nest predation was lowest in areas where no exotic predators were present (12.8), higher in areas with ongoing predator control (33.9%), and highest in areas without control that had the full set of exotic and native nest predators (47.5). Surprisingly, nest predation rates were higher in introduced as compared to native species. Our analyses demonstrated that human-caused factors (introduced predators and prey) overrode factors such as nest type and habitat identified as important in predicting nest predation in North America and Europe previously.

捕食作用是生态学、进化与保护领域的关键驱动因子，因此深入理解捕食作用对于解析生态过程、管理濒危猎物种群具有重要意义。本研究针对新西兰鸣禽（songbirds）的巢捕食率开展了一项覆盖空间维度（从主岛至近海小岛）与时间维度（1938年至2005年）的大规模元分析（meta-analysis），共纳入隶属于17个科的26种鸣禽的79个种群、总计4838个巢的巢捕食率数据。分析结果显示，巢捕食率呈现从西南向东北递增的空间格局，同时在过去60年间持续上升，两种情形下的增幅均达15至25个百分点。本研究明确了外来哺乳动物捕食者的核心影响：无外来捕食者存在的区域巢捕食率最低（12.8），实施持续捕食者管控的区域巢捕食率次之（33.9%），未实施管控且同时存在全部外来与本土巢捕食者的区域巢捕食率最高（47.5%）。令人意外的是，外来鸣禽的巢捕食率显著高于本土鸣禽。本研究分析表明，人为驱动因素（外来捕食者与外来猎物）的影响强度远超此前在北美与欧洲相关研究中被认定为巢捕食率重要预测因子的巢型与栖息地等因素。