The Wood Sandpiper Tringa glareola is a relatively common wader species breeding in Scandinavia (except the South) and further East in Finland, the Baltic States and Russia, all the way to the Bering Strait (CRAMP & SIMMONS, 1983) and from 1969 irregular breeding in North America, Aleutine islands (WHITE et al., 1974). According to data reported in bibliography it is considered as an occasional wintering, a transaharan migrant common during migrations, but irregular in winter (BRICHETTI & FRACASSO, 2015). The species is subdivided into four biogeographic populations. A waterbird “population” can be defined as a distinct assemblage of individuals which does not experience significant emigration or immigration. This definition can onl...