More than two billion birds migrate through the Gulf of Mexico each spring en route to breeding grounds in the USA and Canada. This region has a long history of complex natural and anthropogenic environments as the northern Gulf coast provides the first possible stopover habitats for migrants making nonstop trans-Gulf crossings during spring migration. However, intense anthropogenic activity in the region, which is expanding rapidly at present, makes migrants vulnerable to a multitude of obstacles and increasingly fragments and alters these habitats. Understanding the timing of migrants' overwater arrivals has biological value for expanding our understanding of migration ecology relative to decision-making for nonstop flights, and is imperative for advancing conservation of this critical region through the identification of key times in which to direct conservation actions (e.g. temporary halting of wind turbines, reduction of light pollution). We explored 10 years of weather surveillance radar data from five sites along the northern Gulf of Mexico coast to quantify the daily timing and intensity of arriving trans-Gulf migrants. On a daily scale, we found that migrant intensity peaked an average of nine hours after local sunrise, occurring earliest at easternmost sites. On a seasonal level, the greatest number of arrivals occurred between late April and early May, with peak intensity occurring latest at westernmost sites. Overall intensity of migration across all 10 years of data was greatest at the westernmost sites and decreased moving farther to the east. These findings emphasize the differential spatial and temporal patterns of use of the Gulf of Mexico region by migrating birds, information that is essential for improving our understanding of the ecology of trans-Gulf migration and for supporting data-driven approaches to conservation actions for the migratory birds passing through this critical region.

中文翻译：

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入境抵达：使用天气监视雷达量化春季跨海湾鸟类迁徙的昼夜时间

每年春天，超过 20 亿只鸟类穿过墨西哥湾迁徙到美国和加拿大的繁殖地。该地区有着复杂的自然和人为环境的悠久历史，因为墨西哥湾北部海岸为春季迁徙期间不间断跨海湾穿越的移民提供了第一个可能的中途停留栖息地。然而，该地区目前正在迅速扩张的强烈的人类活动使移民容易受到众多障碍的影响，并日益破碎和改变这些栖息地。了解移民通过水上抵达的时间对于扩大我们对与直飞航班决策相关的移民生态的理解具有生物学价值，通过确定指导保护行动的关键时间（例如暂时停止风力涡轮机、减少光污染），对于推进这一关键地区的保护至关重要。我们研究了墨西哥湾北部海岸五个地点 10 年来的天气监测雷达数据，以量化跨海湾移民每日到达的时间和强度。在日常范围内，我们发现迁徙强度平均在当地日出后九小时达到峰值，最早出现在最东部的地点。从季节性角度来看，到达人数最多的时期是四月下旬至五月初，最西边的地点最晚出现高峰强度。所有 10 年数据中的总体迁移强度在最西边的地点最大，并向东移动则逐渐减弱。