Birds exhibit a remarkable array of seasonal migrations. Despite much research describing migratory behaviour, the underlying forces driving how a species’ breeding and wintering populations redistribute each year, that is, migratory connectivity, remain largely unknown. Here, we test the hypothesis that birds migrate in a way that minimises energy expenditure while considering intraspecific competition for energy acquisition, by developing a modelling framework that simulates an optimal redistribution of individuals between breeding and wintering areas. Using 25 species across the Americas, we find that the model accurately predicts empirical migration patterns, and thus offers a general explanation for migratory connectivity based on first ecological and energetic principles. Our model provides a strong basis for exploring additional processes underlying the ecology and evolution of migration, but also a framework for predicting how migration impacts local adaptation across seasons and how environmental change may affect population dynamics in migratory species.

中文翻译：

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鸟类迁徙连通性的一般理论

鸟类表现出一系列非凡的季节性迁徙。尽管有大量研究描述了迁徙行为，但驱动物种繁殖和越冬种群每年重新分布的潜在力量，即迁徙连通性，在很大程度上仍然未知。在这里，我们通过开发模拟繁殖区和越冬区之间个体最佳重新分配的建模框架，测试鸟类以最小化能量消耗的方式迁徙，同时考虑种内能量获取竞争的假设。使用美洲的 25 个物种，我们发现该模型准确地预测了经验迁移模式，从而提供了基于第一生态和能量原理的迁移连通性的一般解释。