Wood Warblers Phylloscopus sibilatrix have declined considerably throughout most of their
north and western breeding range in Europe but the causes of this decline are unknown.
Declines may be related to factors on the breeding grounds, stopover sites and/or wintering
grounds. We used multi-isotope (δ 2H, δ 13C, δ 15N) measurements of winter-grown
feathers of 314 individuals breeding in the Białowieża Forest (E Poland) to infer where they
wintered in sub Saharan Africa over a 4-year period from 2009–2012. We used both aspatial …