Predation prey games in the evolutionary ecology of migratory species

大多数关于鸟类和其他动物的迁徙路线、迁徙时间以及在繁殖地或非繁殖地定居的研究都集中在与食物和天气的季节性模式的关系上。 本研究考虑了移动的捕食者对猎物迁移行为的几个方面的影响，反之亦然。 捕食者和猎物都应该分散自己，以最大限度地提高繁殖和生存能力，这两套运动相互作用，在某些情况下导致稳定的模式。 正在研究这些动态结果的主要系统是在北极繁殖并在沿着温带和热带海岸线过冬的小鹬，以及它们的猎鹰捕食者。 自从滴滴涕几乎被禁止以来，北美和欧洲的猎鹰数量稳步增加，提供了一个“自然实验”，可以评估猎物行为的变化。 我们研究了猎鹰和鹬如何重新分配自己的越冬地点，因为世界已经变得更加危险的鹬，测试预测，更多的鹬将被发现在更安全，但也许更多的粮食贫困地区。 我们还测试了猎鹰是否迁移到不同的纬度，使更偏北的位置比更偏南的猎物更危险，以及如何与不同的脆弱性，主要是因为身体大小的差异，鹬也迁移到不同的纬度。

Most research on the migration routes, timing of movements, and settlement on breeding or non-breeding grounds of birds and other animals concentrates on relationships with seasonal patterns of food and weather. This research considers the effects of mobile predators on several aspects of migration behaviour of their prey, and vice versa. Both predators and prey should distribute themselves to maximize their reproduction and survivorship, and the two sets of movements interact, in some cases leading to stable patterns. The principle systems where the outcomes of these dynamics are being studied are small sandpipers that breed in the arctic and spend the winter along temperate and tropical coastlines, and their falcon predators. Since the near banning of DDT, falcon populations have steadily increased in North America and Europe, providing a "natural experiment" against which changes in prey behaviour may be assessed. We examine how both falcons and sandpipers have redistributed themselves among wintering sites as the world has become more dangerous for the sandpipers, testing the prediction that more sandpipers will be found at safer, but perhaps more food-poor areas. We also test whether falcons migrate to different latitudes such that more northerly locations are more dangerous for prey than more southerly ones, and how sandpipers with different vulnerabilities, primarily because of differences in body sizes, also migrate to different latitudes.