The Grey Plover Pluvialis squatarola is a wader (Aves: Charadriiformes) breeding in the high Arctic with one of the widest latitudinal distributions during the boreal winter. Its non-breeding distribution encompasses coastal wetlands from the temperate belt of the northern hemisphere to the southernmost tips of the austral continents. Following the ecological definition of Alerstam & Hogsted (1982), the Grey Plover is a typical S-species. Its life history is featured by adaptations to ecological restrictions and high intra-specific competition on the breeding grounds: it has a small clutch size, a deferred age of first breeding, an early emigration from the breeding grounds, a post-breeding and post-migration moult ('winter moult'), and a differential migration with adults moving ahead of juveniles. S-species are therefore excellent candidates to study the adaptations of these biological traits, because they have evolved under the effect of intense competition. The Grey Plover, with its cosmopolitan distribution, enhances these opportunities of comparative studies.