Migratory behavior can differ markedly amongst individuals within populations or species. Understanding the factors influencing this variation is key to understanding how current environmental changes might influence migratory propensity and the distribution and abundance of migratory species across their range. Here, we investigate variation in migratory behavior of the partially migratory Eurasian oystercatcher (Haematopus ostralegus) population breeding in Iceland. We use resightings of color-ringed adults and stable isotopes to determine whether individuals migrate or remain in Iceland during winter and test whether individual migratory strategies vary in relation to sex, body size and breeding location. We also explore individual consistency in migratory strategy and test whether assortative mating with respect to strategy occurs in this population. The proportion of migrants and residents varied greatly across breeding locations, but not with respect to sex or body size. Individuals were consistent in migratory strategy between years and there was no evidence of assortative mating by migratory strategy. We use these findings to explore factors underlying the evolution and maintenance of partial migration at high latitudes.

中文翻译：

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亚北极部分迁徙水鸟迁徙行为的个体差异

迁徙行为在种群或物种内的个体之间可能存在显着差异。了解影响这种变化的因素是了解当前环境变化如何影响迁徙倾向以及迁徙物种在其范围内的分布和丰度的关键。在这里，我们调查了在冰岛繁殖的部分迁徙欧亚牡蛎（Haematopus ostralegus）种群迁徙行为的变化。我们使用对色环成虫和稳定同位素的观察来确定个体是否在冬季迁徙或留在冰岛，并测试个体迁徙策略是否因性别、体型和繁殖地点而异。我们还探索了迁徙策略中的个体一致性，并测试了该种群中是否发生了与策略相关的分类交配。迁徙者和居民的比例因繁殖地而异，但与性别或体型无关。个体在不同年份的迁徙策略上是一致的，并且没有证据表明迁徙策略进行了分类交配。我们使用这些发现来探索高纬度地区部分迁移演变和维持的潜在因素。