Survival of British Sedge Warblers <i>Acrocephalus schoenobaenus</i> in relation to west African rainfall

Fluctuations in the population levels and annual adult survival rates of British Sedge Warblers Acrocephalus schoenobaenus since the late 1960s are strongly correlated with indices of wet season rainfall in the west African winter quarters. Population changes are unrelated to estimates of breeding productivity in the previous year. Habitat availability in the winter quarters has probably been the main factor limiting the size of the Sedge Warbler population in Britain during the period of study.