Phylloscopus collybita is a widespread breeder across much of Europe, which accounts for less than half of its global breeding range. Its European breeding population is extremely large (>30,000,000 pairs), and was stable between 1970-1990. Although there were declines in a few countries-notably France-during 1990-2000, populations were stable or increased across the majority of its European range, and the species remained stable overall.

Breeds in west Palearctic in upper and lower middle latitudes, in continental and oceanic boreal, temperate, and mediterranean climatic zones. Basically a bird of mature lowland woodland with not too dense canopy and fairly copious variety of medium to tallish undergrowth, but may even extend to tree line in mountain woodland or to upper zone of closed forest.

Breeds mid April to mid June in Western Erope. Early May in Central Europe, mid April to May in Spain, late January to June in Canary Islands. Nest site is built on or close to ground concealed in tall vegetation, low bushes, tree branches, or creepers. Nest is a domed structure with side entrance, made of dry grass stems and leaves, moss, and other plant leaves, lined with finer grasses and feathers. 4-7 eggs are laid, incubation 13-15 days, by female only.

Almost wholly insects. Forages mainly high in tree canopy, aslo in bushes and lower down in dense thickets.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population, including an estimated 60,000,000-120,000,000 individuals in Europe (BirdLife International in prep.). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

Most populations migratory; Canary Islands populations sedentary. Western populations winter within and south of breeding areas, eastern populations vacate breeding areas entirely. Winters south to northern Afrotropics, Arabia, and northern India. Within Britain, recoveries provide evidence that some breeding birds remain for winter, and that individuals return to same area in successive winters; also evidence of continental birds wintering in Britain. Autumn movement begins August and is protracted, though termination of passage often masked by overwintering. Spring departure from wintering areas begins in February, with main movement March-April. Migrants reach all south coast observatories in Britain by beginning of March; peak early April in west (where passage heavier and more sustained than in east), not until mid-April in east. Main arrival in Switzerland from mid-March, in mountains from early April. In southern Sweden, passage early April to mid-June, peaking in early May. Further east, movement is later: not before mid-April in Moscow region.

article number 1 Title
Mate Fidelity in Chiffchaff Phylloscopus collybita
Author(s): Pavel Brandl
Abstract: Two cases of year-to-year mate fidelity in Chiffchaff occurred in the subpopulation of 6 males and their females in a region of South Bohemia. The first nesting of both females failed in the first sea..[more]..
Source: J. Orn. 137: 528-531
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