Seasonal bird migration occurs on large spatial scales and is influenced by many factors including weather conditions. Weather can include thunderstorms, which may force migrants to land or cause them to reroute a migration path. In this study, a sample of isolated thunderstorms was analyzed from the domains of three weather radars in the central United States to test hypotheses regarding the influence of thunderstorms on the distribution of migrants. Migrating bird density was often reduced in the wake of storms, and this wake reduction was typically more pronounced for larger, more intense and faster-moving storms, particularly in eastern Nebraska. Wind conditions more strongly influence the distribution and density of migrating birds in fall than in spring, providing evidence that migrating birds respond to environmental signals more readily in the fall. This finding supports the concept that birds are more strongly obligated to cover distance in the spring and arrive in their breeding range on time. Wind conditions at the surface were generally more important to migrant density and distribution than wind conditions closer to flight level.

中文翻译：

---

孤立雷暴和低空风场对北美中部夜间迁徙鸟类的影响

季节性鸟类迁徙发生在较大的空间尺度上，并受到包括天气条件在内的许多因素的影响。天气可能包括雷暴，这可能会迫使移民登陆或改变迁徙路线。在这项研究中，分析了来自美国中部三个天气雷达域的孤立雷暴样本，以检验有关雷暴对移民分布影响的假设。风暴过后，候鸟密度通常会降低，而这种尾流减少通常在更大、更强烈和移动速度更快的风暴中更为明显，尤其是在内布拉斯加州东部。与春季相比，秋季风力条件对候鸟的分布和密度的影响更大，提供证据表明候鸟在秋季更容易对环境信号做出反应。这一发现支持这样一种观点，即鸟类更有义务在春季远距离飞行并准时到达它们的繁殖范围。与接近飞行高度的风况相比，地表的风况通常对移民密度和分布更为重要。