ИСТИНА

It was long held that Sanderlings (Calidris alba) breeding in northeast Greenland occurred in western Europe only during migration to and from non-breeding areas in western Africa, whereas birds wintering in western Europe were of Siberian breeding origin. However, recent ring-recoveries show that Greenlandic Sanderlings winter all along the North Sea and Atlantic coasts from the United Kingdom to South Africa, while evidence of Siberian birds wintering in Europe has yet to materialize. In Red Knots, which share nearly identical breeding habitats and distribution with Sanderlings, Greenland and Siberian populations (C. canutus islandica and canutus, respectively) are among the most distantly related among six subspecies. If the analogous Sanderling populations are similarly differentiated, this may: 1) support a similar global expansion in the two species, and 2) provide a molecular tool for assessing the breeding origin of Sanderlings along the East Atlantic Flyway. However, we found no significant genetic differentiation (in mtDNA and seven microsatellite loci) between Sanderling breeding populations separated by 2,000 km and differing in migration timing and routes. These results suggest a very different evolutionary history than Red Knots, and may reflect recent colonization of a flyway or unexpectedly high exchange of individuals between breeding areas.