Editing Common chiffchaff (section)

==Description==
The common chiffchaff is a small, dumpy, {{convert|10-12|cm|in|abbr=off}} long leaf warbler. The male weighs 7–8&nbsp;grammes (0.28–0.31&nbsp;oz), and the female 6–7&nbsp;grammes (0.25–0.28&nbsp;oz).{{sfn|Clement|1995|p=59}}<!--supports weights only--> The spring adult of the western [[Subspecies#Nomenclature|nominate subspecies]] '' P. c. collybita'' has brown-washed dull green upperparts, off-white underparts becoming yellowish on the flanks, and a short whitish [[supercilium]]. It has dark legs, a fine dark bill, and short [[Flight feather#Primary extension|primary projection]] (extension of the [[flight feather]]s beyond the folded wing).{{sfn|Clement|1995|pp=13–14}} As the plumage wears, it gets duller and browner, and the yellow on the flanks tends to be lost, but after the breeding season there is a prolonged complete [[moulting|moult]] before migration. The newly fledged juvenile is browner above than the adult, with yellow-white underparts, but moults about 10 weeks after acquiring its first plumage. After moulting, both the adult and the juvenile have brighter and greener upperparts and a paler supercilium.{{sfn|Clement|1995|pp=15–16}}<!--supports moult only-->
[[File:Common Chiffchaff.jpg|thumb|left|Common chiffchaff]]
[[File:Phylloscopus collybita.jpg|Nominate subspecies <br />''P. c. collybita'' in [[Newcastle upon Tyne]]|thumb]]

This warbler gets its name from its simple distinctive song, a repetitive cheerful ''{{not a typo|chiff-chaff}}''. This song is one of the first [[bird|avian]] signs that spring has returned. Its call is a ''{{not a typo|hweet}}'', less [[syllable|disyllabic]] than the ''{{not a typo|hooeet}}'' of the willow warbler or ''{{not a typo|hu-it}}'' of the [[western Bonelli's warbler]].<ref name= Collins>Mullarney, Killian; Svensson, Lars, Zetterstrom, Dan; Grant, Peter. (1999). ''Birds of Europe.'' London. HarperCollins. pp. 304–306 {{ISBN|0-00-219728-6}}</ref>

The song differs from that of the Iberian chiffchaff, which has a shorter ''{{not a typo|djup djup djup wheep wheep chittichittichiittichitta}}''. However, mixed singers occur in the hybridisation zone and elsewhere, and can be difficult to allocate to species.<ref name = BB101/>

When not singing, the common chiffchaff can be difficult to distinguish from other leaf warblers with greenish upperparts and whitish underparts, particularly the willow warbler. However, that species has a longer primary projection, a sleeker, brighter appearance and generally pale legs. Bonelli's warbler (''P. bonelli)'' might be confused with the common chiffchaff subspecies ''tristis'', but it has a plain face and green in the wings.{{sfn|Clement|1995|p=26}} The common chiffchaff also has rounded wings in flight, and a diagnostic tail movement consisting of a dip, then sidewards wag, that distinguishes it from other ''Phylloscopus'' warblers<ref name= BWP/> and gives rise to the name "tailwagger" in India.<ref name=Simms/>

Perhaps the greatest challenge is distinguishing non-singing birds of the nominate subspecies from Iberian chiffchaff in the field. In [[Great Britain]] and the [[Netherlands]], all accepted records of vagrant Iberian chiffchaffs relate to singing males.<ref name = BB101/>