Common chiffchaff

Did You Know?

• The common chiffchaff is occasionally a host of brood parasitic cuckoos, including the common and Horsfield's cuckoos, but it recognises and rejects non-mimetic eggs.
• The record lifespan for a common chiffchaff is more than seven years.
• The subspecies exsul is probably extinct.

Taxonomy

The common chiffchaff was first formally described as Sylvia collybita by French ornithologist Louis Pierre Vieillot in 1817 in his Nouveau Dictionnaire d'Histoire Naturelle, with the type locality being the French region of Normandy. The British naturalist Gilbert White was among the first to separate the similar-looking common chiffchaff, willow warbler and wood warbler by their songs, as detailed in 1789 in The Natural History and Antiquities of Selborne. The genus Phylloscopus, described by German zoologist Friedrich Boie in 1826, contains about 80 species of small insectivorous Old World woodland warblers; it was formerly part of the family Sylviidae but has now been split off as Phylloscopidae. The chiffchaff's closest relatives, other than former subspecies, are a group of leaf warblers lacking crown stripes, a yellow rump or obvious wing bars, including the willow, Bonelli's, wood and plain leaf warblers. An old synonym for the chiffchaff was Phylloscopus rufus. The common chiffchaff has three still commonly accepted subspecies: the nominate P. c. collybita, which breeds in Europe east to Poland and Bulgaria; P. c. abietinus, occurring in Scandinavia and northern Russia; and P. c. tristis. Some forms from the Iberian Peninsula, the Canary Islands, and the Caucasus are now more often treated as full species. Some common chiffchaffs in the Middle East are browner and have a more disyllabic swee-hu call than P. c. abietinus, and may belong to a poorly known taxon "brevirostris"; further research is needed to clarify the affinities of this form.

Description

The common chiffchaff is a small, plump leaf warbler, about 10 to 12 cm long. Males weigh between 7 and 8 grams, while females are slightly lighter at 6 to 7 grams. In spring, the adult of the western nominate subspecies shows brown-tinged dull green upperparts, off-white underparts that turn yellowish on the flanks, and a short, pale stripe above the eye. It has dark legs, a thin dark bill, and short flight feathers beyond the folded wing. As the bird’s feathers wear, they become duller and browner, and the flank yellow fades. After breeding, it undergoes a long, complete moult before migrating. Newly fledged juveniles are browner above than adults, with yellow-white underparts, and they moult about ten weeks after getting their first feathers. After moulting, both adults and juveniles have brighter, greener upperparts and a paler eye stripe. The bird’s name comes from its simple, cheerful, repetitive chiff-chaff song, an early sign of spring. Its call is a hweet, less two-syllabled than the willow warbler’s hooeet or the western Bonelli’s warbler’s hu-it. When silent, it can be hard to tell apart from other greenish leaf warblers. However, the common chiffchaff has rounded wings in flight and a distinctive tail movement: a dip followed by a sideways wag.

Distribution and habitat

The common chiffchaff raises its young across a broad sweep from Europe and Asia into eastern Siberia, reaching as far north as 70°N, with separate groups in northwest Africa, parts of Turkey, and northwestern Iran. It migrates, yet it is among the earliest small songbirds to come back to its nesting grounds in spring and among the last to leave in late autumn. For breeding, it prefers open woodlands that have some taller trees, at least five meters high, and ground cover like a sparse to moderate mix of grasses, bracken, or nettles for nesting. In winter, it adapts to a broader range of habitats, including scrub, and often stays near water. More birds are now spending the winter farther north in western Europe than in the past, especially along the coast of southern England and in London’s mild city climate.

Behaviour

The male common chiffchaff is fiercely protective of its breeding territory, which is usually about 20 meters wide. It will chase off other males and even attack small birds that come too close. This bird is bold and curious, willing to confront dangerous predators like stoats or egg-stealing Eurasian jays near the nest. Its song, delivered from a high perch, is used to mark its territory and communicate with the female, not to guard against other males fathering her chicks. Outside the core territory, the bird has a larger feeding area, often ten times bigger, and the female’s feeding range is thought to be larger than the male’s. After breeding, the territory is abandoned, and the birds may join small flocks with other warblers before migrating.

The male arrives at the breeding site two to three weeks before the female and begins singing right away to claim the area and attract a mate. During courtship, he performs a slow, butterfly-like flight. Once a pair bonds, he drives away any other females. The male’s main role is defending the territory; he has little to do with nesting. The female builds a domed nest on or near the ground, hidden in brambles, nettles, or dense low plants. It has a side entrance and is made from coarse dead leaves and grass, lined with finer material and feathers. The nest is about 12.5 cm high and 11 cm wide.

The female lays two to seven eggs, usually five or six, which are cream-colored with tiny red, purple, or black spots, each about 1.5 cm long and 1.2 cm across. She incubates them for 13 to 14 days. The chicks hatch naked and blind, and she broods and feeds them for another 14 to 15 days until they fledge. The male rarely helps feed the young, except in bad weather when insects are scarce or if the female disappears. After leaving the nest, the chicks stay nearby for three to four weeks, fed and roosting with the female, though this care lessens after about 14 days. In northern areas, only one brood is possible due to the short summer, but two broods are common in central and southern regions.