The chiffchaffs are a wide-ranging group of small warblers, all rather similarly plumaged, being mainly drab olive-brown without obvious markings. They occur in various ‘flavours’ throughout Europe and northern Asia in woodland habitats and closely related forms also breed in the Canary Islands. The name is onomatopoeic, but the classic ‘chiff-chiff-chaff’ is uttered only by the northern forms.
In Portugal we have a separate species, the Iberian Chiffchaff, which is a summer visitor and has a very different song: a series of ‘chaffs’ followed by a couple of high ‘sweets’ and a short, fast trill. One eccentric bird in the valley below my house just produced a long series of ‘chaffs’ - seventeen counted on one occasion! The contact call is a loud ‘weeet’. In the breeding season it is paler than its northern relative, with a more clearly defined eye stripe and a hint of yellow in the underparts. It also has dark red legs, so is in between the black-legged Common Chiffchaff (a winter visitor in large numbers) and the pale-legged Willow Warbler, a common migrant, in general appearance.
Iberian Chiffchaffs spend the winter in sub-Saharan Africa. The first birds return in early March and quickly occupy breeding territories in both mature woodland and scrubland. Most have returned south again by late September. Although the normal range does not extend beyond Iberia, a few ‘overshooting’ spring migrants reach northern Europe, including the British Isles. It is likely some juveniles also migrate north instead of south in autumn (the curious phenomenon of ‘reverse migration’ occurs in the populations of most migratory passerines) and I once saw a late September bird on Tresco, Isles of Scilly.
The Common Chiffchaff’s breeding range extends only as far south as northern Spain but it is one of the most numerous winter visitors to Portugal, occurring in a wide range of habitats from woodland, scrub and gardens to meadows and marshes, where it can sometimes be seen in sizeable flocks. They often feed on the ground or in low vegetation but also take insects attracted to late flowering eucalyptus trees.