Sabo Ann M, Hagemeyer Natasha D G, Lahey Ally S, Walters Eric L
Department of Biological Sciences, Old Dominion University , Norfolk, Virginia , United States.
PeerJ. 2016 Jun 23;4:e2170. doi: 10.7717/peerj.2170. eCollection 2016.
Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn of 2013 and 2014. We focused on three factors likely to contribute to an individual's predisposition to collide with windows: (i) taxonomic classification, (ii) age, and (iii) migrant vs. resident status. Thrushes, dominated by the partial migrant American Robin (Turdus migratorius), were significantly less likely to strike glass than be sampled in mist nets (χ(2) = 9.21, p = 0.002), while wood-warblers (Parulidae) were more likely to strike than expected (χ(2) = 13.55, p < 0.001). The proportion of juveniles striking windows (45.4%) was not significantly different (χ(2) = 0.05, p = 0.827) than the population of juvenile birds naturally occurring at the zoo (48.8%). Migrants, however, were significantly more susceptible to window strikes than residents (χ(2) = 6.35, p = 0.012). Our results suggest that resident birds are able to learn to avoid and thus reduce their likelihood of striking windows; this intrinsic risk factor may help explain the apparent susceptibility of certain taxa to window strikes.
在北美，每年有多达10亿只鸟因撞击窗户而死亡。透明和反光的玻璃窗都是令人担忧的原因，它们要么作为对所需资源不可见、无法穿透的屏障误导鸟类，要么在大面积上反射这些资源。大量的窗户撞击事件发生在鸟类迁徙期间，但对于易感性因素，或者特定鸟类分类群是否比其他鸟类更易受影响，我们知之甚少。我们报告了一项于2013年秋季和2014年在美国弗吉尼亚州诺福克市弗吉尼亚动物园进行的关于窗户撞击和雾网捕获数据的研究。我们关注了可能导致个体倾向于与窗户碰撞的三个因素：（i）分类学分类，（ii）年龄，以及（iii）候鸟与留鸟状态。以部分候鸟美洲知更鸟（旅鸫）为主的鸫科鸟类撞击玻璃的可能性明显低于在雾网中被捕获的可能性（χ(2)=9.21，p = 0.002），而林莺科鸟类撞击的可能性高于预期（χ(2)=13.55，p < 0.001）。撞击窗户的幼鸟比例（45.4%）与动物园自然出现的幼鸟种群比例（48.8%）没有显著差异（χ(2)=0.05，p = 0.827）。然而，候鸟比留鸟更容易受到窗户撞击（χ(2)=6.35，p = 0.012）。我们的结果表明，留鸟能够学会避开从而降低撞击窗户的可能性；这种内在风险因素可能有助于解释某些分类群对窗户撞击的明显易感性。
