The aim of this paper is to review information on systematic position, distribution ranges, habitat requirements, morphology, and ecology of the leaf warblers (Phylloscopus spp.). Closely related species of this group present different migration strategies. Exhibiting many inter-specific similarities in morphology and ecological requirements, leaf warblers reveal high intra-specific variability. The morphological differentiation of individual species, subspecies, populations, and age-sex groups, affords considerable possibilities for migration studies, especially those concerning the basis of migration strategy. Leaf warblers make a group of model species, being a good subject for ecological studies. The knowledge of their migration strategies may be a good reference point for understanding a general pattern of the migration of European passerines.
