Seasonal migration has been alternately proposed to promote geographic range size in some contexts and to constrain it in others, but it remains unclear if migratory behavior has a general effect on range size. Because migration involves movement, most hypotheses about the relationship between migration and range size invoke an influence of migration on the process of dispersal‐mediated range expansion. Intuitively, a positive relationship between migratory behavior and dispersal ability could bolster range expansion among migratory species, yet some biogeographic patterns suggest that long‐distance migration may instead impede range expansion, especially in the temperate zone. We conducted a comparative analysis of the relationship between migratory behavior and range size by testing the effect of migratory status, migration distance and morphological dispersal ability on breeding range size among all temperate North American passerines. Further, we assessed whether these traits affect range expansion into suitable habitat by analyzing their relationship with range filling (the proportion of climatically‐suitable area occupied, or ‘filled’ by a species). Contrary to previous studies, we found migration and dispersal ability to be poor predictors of range size and range filling in North America. Rather, most variation in range size is explained by latitude. Our results suggest that migratory behavior does not affect range size within the scale of a continent, and furthermore, that temperate North American passerines’ breeding ranges are not influenced by their dispersal abilities. To better understand why migratory behavior appears to promote range size in some contexts and constrain it in others, future studies should investigate how migratory behavior affects dispersal at the individual level, as well as the relationship between the evolution of migratory behavior and the breadth of species’ climatic niches.

中文翻译：

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季节性迁徙对北美温带雀形目的范围大小的影响

有人提出了季节性迁徙，以在某些情况下提高地理范围的大小，在其他情况下限制地理范围的大小，但目前尚不清楚迁徙行为是否对范围大小有普遍影响。由于迁移涉及运动，因此大多数关于迁移与范围大小之间关系的假设都涉及迁移对分散介导的范围扩展过程的影响。直觉上，迁徙行为与传播能力之间的正相关关系可能会促进迁徙物种之间的范围扩展，但是一些生物地理学模式表明，长距离迁移可能反而会阻碍范围扩展，特别是在温带地区。通过测试迁移状态的影响，我们对迁移行为与范围大小之间的关系进行了比较分析，北美距离温带雀形目的迁徙距离和形态扩散能力对繁殖范围大小的影响。此外，我们通过分析它们与范围填充（物种所占或“填充”的气候适合区域的比例）之间的关系来评估这些特征是否影响范围扩展到合适的栖息地。与以前的研究相反，我们发现迁移和扩散能力不能很好地预测北美的范围大小和范围填充。相反，范围大小的大多数变化是由纬度解释的。我们的结果表明，迁徙行为不会影响一个大陆范围内的范围，而且，北美温带雀形目的繁殖范围不受其散布能力的影响。