Background Research on bird-window collision mitigation is needed to prevent up to a billion bird fatalities yearly in the U.S. At the University of Utah campus (Salt Lake City, Utah, USA), past research documented collisions, especially for Cedar Waxwings (Bombycilla cedrorum) drawn to fruiting ornamental pears in winter. Mirrored windows, which have a metallic coating that turns window exteriors into mirrors, had frequent collisions, which were mitigated when Feather Friendly®bird deterrent markers were applied. Bird-friendly windows–ORNILUX®ultraviolet (UV) and fritted windows–also reduced collisions when data were collected across fall and winter. Extending this prior research, we evaluated additional mitigation and tested the replicability of effects for pear trees, mirrored windows, and bird-friendly windows across two years. Methods Using published data from eight buildings monitored for collisions in year 1 (Fall and Winter, 2019–2020), we added another year of monitoring, Fall and Winter, 2020–2021. Between years, Feather Friendly®mitigation markers were added to collision-prone areas of two buildings, including both mirrored and transparent windows. Results The two buildings that received new Feather Friendly®mitigation had significantly fewer collisions post-mitigation. Control areas also had nonsignificant decline in collisions. The interaction of area (mitigation vs. control) by time (year 1 vs. 2) was significant, based on generalized estimating equations (GEE). The total yearly collisions across all eight buildings declined from 39 to 23. A second GEE analysis of all 8 buildings showed that mirrored windows, pear trees, and bird-friendly windows were each significant when analyzed separately. The best-fit model showed more collisions for mirrored windows and fewer collisions for bird-friendly windows. We found pear tree proximity to be related to more collisions in winter than fall. In addition, pear trees showed reduced collisions from year 1 to 2, consistent with new mitigation for two of three buildings near pear trees. Discussion Feather Friendly® markers can mitigate collisions with transparent windows, not only mirrored windows, compared to unmitigated areas over 2 years. Results also underscore the dangers of pear tree proximity and mirrored windows and the efficacy of bird-friendly windows. Thus, bird collisions can be prevented by window mitigation, permanent bird-friendly windows, and landscape designs that avoid creating ecological traps.

中文翻译：

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鸟窗碰撞：两年内的缓解效果和风险因素

背景 在美国，需要对减轻鸟窗碰撞进行研究，以防止每年多达 10 亿只鸟死亡 在犹他大学校园（美国犹他州盐湖城），过去的研究记录了碰撞，尤其是雪松蜡翼（Bombycilla cedrorum ) 被冬季开花结果的观赏梨所吸引。镜面窗户具有金属涂层，可将窗户外部变成镜子，经常发生碰撞，使用 Feather Friendly® 防鸟标记后，这种情况得到缓解。鸟类友好的窗户——ORNILUX® 紫外线 (UV) 和烧结窗户——在收集秋季和冬季的数据时也减少了碰撞。扩展这项先前的研究，我们评估了额外的缓解措施，并测试了两年内梨树、镜面窗户和鸟类友好窗户的效果的可复制性。方法 使用第一年（2019-2020 年秋季和冬季）监测碰撞的八座建筑物的已发布数据，我们增加了另一年的监测，即 2020-2021 年秋季和冬季。多年来，Feather Friendly® 缓解标记被添加到两座建筑物的易碰撞区域，包括镜像和透明窗户。结果 接受新 Feather Friendly® 缓解措施的两座建筑物在缓解后发生的碰撞明显减少。控制区的碰撞也没有显着下降。基于广义估计方程 (GEE)，区域（缓解与控制）与时间（第 1 年与第 2 年）的相互作用是显着的。所有 8 座建筑物的年度碰撞总数从 39 次下降到 23 次。对所有 8 座建筑物的第二次 GEE 分析表明，镜面窗户、梨树、单独分析时，鸟类友好的窗户都非常重要。最佳拟合模型显示镜像窗户的碰撞次数较多，而鸟类友好窗户的碰撞次数较少。我们发现梨树接近与冬季比秋季更多的碰撞有关。此外，梨树从第 1 年到第 2 年显示碰撞减少，这与梨树附近三座建筑物中的两座的新缓解措施一致。讨论 Feather Friendly® 标记可以减轻与透明窗户的碰撞，而不仅仅是镜面窗户，与 2 年内未缓解的区域相比。结果还强调了梨树接近和镜像窗户的危险以及鸟类友好窗户的功效。因此，可以通过窗户缓解措施、永久性的鸟类友好窗户和避免产生生态陷阱的景观设计来防止鸟类碰撞。