Common chiffchaff of grasses, bracken, nettles or similar plants. Its breeding habitat is quite specific, and even near relatives do not share it; for example, the willow warbler ("P. trochilus") prefers younger trees, while the wood warbler ("P. sibilatrix") prefers less undergrowth. In winter, the common chiffchaff uses a wider range of habitats including scrub, and is not so dependent on trees. It is often found near water, unlike the willow warbler which tolerates drier habitats. There is an increasing tendency to winter in western Europe well north of the traditional areas, especially in coastal southern England and the mild urban microclimate
Handbook of the Birds of the World a non-profit endeavour fuelled by material from more than one hundred contributors from around the world. In early 2013, Lynx Edicions launched the online database HBW Alive, which includes the volume and family introductions and updated species accounts from all 17 published HBW volumes. Since its launch, the taxonomy has been thoroughly revised and updated twice (once for non-passerines and once for passerines), following the publication of the two volumes of the "HBW and BirdLife International Illustrated Checklist of the Birds of the World". The Handbook of the Birds of the World Alive site also provides a free access 'Key