Bird-building collisions increase with weather conditions that favor nocturnal migration and with inclement and changing weather

Collisions with building windows are a top bird mortality source, but few studies have evaluated how bird-window collisions are influenced by the weather. By monitoring collisions daily at 21 buildings in Minneapolis, Minnesota, over 4 migration seasons, we show that weather influences the number of window collisions of nocturnal migrants in spring and fall, indicating that collisions may be forecastable based on weather conditions. Collisions increased with weather favoring migration, such as consecutive nights of south wind in spring and even short periods of north wind in fall. We also found evidence that spring and fall collisions increase with weather changes that impede migration, such as changes from fair conditions and tailwinds early in the night to headwinds near sunrise. Our study suggests complex weather effects never before considered in the context of bird collisions, including possible time lag effects of conditions two and three nights before collisions occur, effects of multi-day sequences of conditions, and interactions between conditions at different times of the night. More research is needed to determine if the accuracy of weather-based collision prediction systems improves by integrating such nuances and to clarify mechanisms through which these complex effects operate, such as influences of weather on migration intensity and collision avoidance behavior. Weather-based forecasts may allow refinement of collision mitigation approaches (e.g., reducing building lighting on certain nights or using temporary glass coverings or treatments). However, because challenges remain to communicating such temporally targeted actions and implementing them in a timely manner, other bird-friendly practices (e.g., season-long lighting reduction and permanent glass treatments) should continue to be prioritized.

建筑物窗户碰撞是鸟类致死的首要因素之一，但现有研究极少探讨天气对鸟类撞窗事件的影响。本研究在明尼苏达州明尼阿波利斯市的21栋建筑处开展每日监测，历时4个迁徙季，结果显示天气会影响春、秋两季夜行性迁徙鸟类的撞窗数量，表明可基于天气条件对撞窗事件进行预测。当天气条件有利于迁徙时，撞窗事件会增多，例如春季连续多夜的南风，乃至秋季的短时北风。本研究还发现，当天气变化阻碍迁徙时，春、秋两季的撞窗事件同样会增多，例如夜间初期为晴好天气与顺风、临近日出时转为逆风的天气变化过程。本研究揭示了此前鸟类撞窗研究中未被关注的复杂天气影响效应，包括撞窗发生前两至三夜的天气条件可能存在的滞后效应、多日连续天气条件的影响，以及夜间不同时段天气条件间的交互作用。未来仍需开展更多研究，以明确纳入此类细微影响因素是否可提升基于天气的撞窗预测系统的准确率，并厘清这些复杂效应的作用机制，例如天气对迁徙强度以及避撞行为的影响。基于天气的预测可帮助优化鸟类撞窗减缓措施，例如在特定夜晚降低建筑灯光，或使用临时玻璃覆盖物或涂层。但由于此类针对特定时段的行动在宣传与及时落实方面仍存在挑战，其他鸟类友好型措施，例如全迁徙季降低灯光照明以及永久性玻璃涂层处理，仍应作为优先选项。