Species limits in Acrocephalus and Hippolais warblers from the Western Palearctic

The taxonomic affiliations within the genera [Acrocephalus] and [Hippolais] have long been a matter for debate. Recent molecular and behavioural studies have provided a wealth of new data which can be used to analyse the evolutionary relationships of the Palearctic taxa in these genera. In this paper, we make a series of recommendations for changes in species limits, highlight some problem areas and discuss situations where more research is needed.