Data from: Artificial light at night confounds broad-scale habitat use by migrating birds

With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.

当前全球多数迁徙鸟类种群数量正以令人警觉的速度下降，针对迁徙威胁所引发的种群响应开展大范围评估，对成功开展鸟类保护工作而言或至关重要。多数鸟类于夜间在日益被光污染笼罩的空域中迁徙。明亮的人工光源既会吸引飞行中的迁徙鸟类，使其与各类建筑结构发生碰撞，也可能干扰其对迁徙停歇栖息地的选择，进而影响其获取食物资源的能力。本研究借助美国东北部地区针对夜行性迁徙鸟类的多年天气雷达（weather radar）观测数据，证实：在区域尺度上，秋季迁徙鸟类的停留密度会随与最明亮区域的距离缩短而升高，但在距离明亮光源数公里的范围内则会下降。这一发现意味着，飞行中的鸟类会在大范围尺度上被人工光源吸引，从而阻碍其对大面积森林栖息地的选择。鉴于优质迁徙停歇栖息地对鸟类顺利完成迁徙至关重要，且迁徙途中的阻碍会降低种群适合度，人工光源对迁徙鸟类种群的保护威胁或已愈发凸显。