Willow warbler | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Phylloscopidae |
Genus: | Phylloscopus |
Species: | P. trochilus |
Binomial name | |
Phylloscopus trochilus | |
Subspecies | |
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Yellow: Breeding (summer only) Blue: Non-breeding winter visitor Cross-hatched: migration. | |
Synonyms | |
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The willow warbler (Phylloscopus trochilus) is a very common and widespread leaf warbler which breeds throughout northern and temperate Europe and the Palearctic, from Ireland east to the Anadyr River basin in eastern Siberia. It is strongly migratory, with almost all of the population wintering in sub-Saharan Africa. [2] [3]
It is a bird of open woodlands with trees and ground cover for nesting, including most importantly birch, alder, and willow habitats. The nest is usually built in close contact with the ground, often in low vegetation. Like most Old World warblers (Sylviidae), this small passerine is insectivorous. [3] In northern Europe, it is one of the first warblers to return in the spring, though later than the closely related chiffchaff. [3] In spite of its small size, the willow warbler performs one of the longest migrations of any animal. [2] [4]
The willow warbler was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Motacilla trochilus. [5] The willow warbler is now one of around 80 species placed in the genus Phylloscopus that was introduced by the German zoologist Friedrich Boie in 1826. [6] [7] The genus name combines the Ancient Greek phullon meaning "leaf" and skopos meaning "seeker" (from skopeo, "to watch"). The specific epithet is Ancient Greek meaning "wren". [8]
Before the English name was standardised to willow warbler by William Yarrell in 1843, it was merged with the chiffchaff and wood warbler as the "willow wren". [9] [10]
Three subspecies are recognised. [7] There is a clinal reduction in green and yellow plumage tones from west to east, with central birds browner and easternmost birds predominantly greyish: [2]
The willow warbler is a typical leaf warbler in appearance, 11–12.5 cm (4.3–4.9 in) long and 7–15 g (0.25–0.53 oz) weight. It is greenish brown above and off-white to yellowish below; the wings are plain greenish-brown with no wingbars. Juveniles are yellower below than adults. It is very similar to the chiffchaff, but non-singing birds can be distinguished from that species by their paler pinkish-yellow legs (dark brown to blackish in chiffchaff), longer paler bill, more elegant shape and longer primary projection (wingtip). Its song is a simple repetitive descending whistle, while the contact call is a disyllabic 'hoo-eet', distinct from the more monosyllabic 'hweet' of chiffchaffs. [2] [3] [4] [11]
All populations are highly migratory, with the subspecies P. t. yakutensis migrating up to 12,000 km (7,500 mi) from eastern Siberia to southern Africa along the Asian–East African Flyway, one of the longest migrations of any for a bird of its size. [2] [4] Approximate timings are:
Willow warblers prefer young, open, scrubby woodland with small trees, including human-altered habitats such as coppice and young plantations up to 10–20 years old. High amounts of birch, alder and willow, with good lichen amounts, and water features (e.g. streams), fields with large amounts of bracken and mosses, and patches of low bramble (for nest cover) are preferred, but it will use a wide range of other species, including young or open coniferous forests. [4] [12] Incorporating woodland ride edge thickets of varying structure and height is beneficial. They prefer damp woodland areas. Thicket forming shrubs like blackthorn provide pockets of habitat. Deer browsing can degrade the required low cover.
The highest population densities are found in Scandinavia (where it is the commonest bird of any), with up to 1,100 pairs per square kilometre, and a total population in Sweden and Finland of 24 million pairs. Lower densities occur further east, with peak densities of 27 pairs per square kilometre in central Siberia. Even lower densities are found on the southern edge of the breeding range, with just 9 pairs per square kilometre in Switzerland, and a total of just 100 pairs in the whole of northern Spain. [2]
In England this species has on average decreased in population by 70% within the last 25 years, with the biggest declines in the southeast. In Scotland some increases have occurred. The Forestry Commission offers grants under a scheme called England's Woodland Improvement Grant (EWIG); as does Natural England's Environmental Stewardship Scheme. [12]
Leaf warblers are small insectivorous passerine birds belonging to the genus Phylloscopus.
The common chiffchaff, or simply the chiffchaff, is a common and widespread leaf warbler which breeds in open woodlands throughout northern and temperate Europe and the Palearctic.
The wood warbler is a common and widespread leaf warbler which breeds throughout northern and temperate Europe, and just into the extreme west of Asian Russia in the southern Ural Mountains.
The greenish warbler is a widespread leaf warbler with a breeding range in northeastern Europe, and temperate to subtropical continental Asia. This warbler is strongly migratory and winters in India. It is not uncommon as a spring or early autumn vagrant in Western Europe and is annually seen in Great Britain. In Central Europe large numbers of vagrant birds are encountered in some years; some of these may stay to breed, as a handful of pairs does each year in Germany.
Pallas's leaf warbler or Pallas's warbler, is a bird that breeds in mountain forests from southern Siberia east to northern Mongolia and northeast China. It is named for German zoologist Peter Simon Pallas, who first formally described it. This leaf warbler is strongly migratory, wintering mainly in south China and adjacent areas of southeast Asia, although in recent decades increasing numbers have been found in Europe in autumn.
The yellow-browed warbler is a leaf warbler which breeds in the east Palearctic. This warbler is strongly migratory and winters mainly in tropical South Asia and South-east Asia, but also in small numbers in western Europe. Like the rest of Phylloscopidae, it was formerly included in the Old World warbler assemblage.
The common redshank or simply redshank is a Eurasian wader in the large family Scolopacidae.
The dunlin is a small wader, formerly sometimes separated with the other "stints" in the genus Erolia. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from dun, "dull brown", with the suffix -ling, meaning a person or thing with the given quality.
The Eurasian oystercatcher also known as the common pied oystercatcher, or just oystercatcher, is a wader in the oystercatcher bird family Haematopodidae. It has striking black and white plumage, a long straight orange-red bill, red eyes and relatively short dull pink legs. The sexes are similar in appearance but the bill of the female is longer than that of the male.
The common scoter is a large sea duck, 43–54 cm (17–21 in) in length, which breeds over the far north of Europe and the Palearctic east to the Olenyok River. The black scoter of North America and eastern Siberia was formerly considered to be a subspecies.
The goldcrest is a very small passerine bird in the kinglet family. Its colourful golden crest feathers, as well as being called the "king of the birds" in European folklore, gives rise to its English and scientific names. The scientific name, R. regulus, means 'petty king' or prince. Several subspecies are recognised across the very large distribution range that includes much of the Palearctic and the islands of Macaronesia and Iceland. Birds from the north and east of its breeding range migrate to winter further south.
The Eurasian pygmy owl is the smallest owl in Europe. It is a dark reddish to greyish-brown, with spotted sides and half of a white ring around the back of the neck. This species is found in the boreal forests of Northern and Central Europe to Siberia.
The velvet scoter is a large sea duck, which breeds over the far north of Europe and the Palearctic west of the Yenisey basin. The genus name is derived from Ancient Greek melas "black" and netta "duck". The species name is from the Latin fuscus "dusky brown".
The tree pipit is a small passerine bird which breeds across most of Europe and the Palearctic as far East as the East Siberian Mountains. It is a long-distance migrant moving in winter to Africa and southern Asia. The scientific name is from Latin: anthus is the name for a small bird of grasslands, and the specific trivialis means "common".
The sedge warbler is an Old World warbler in the genus Acrocephalus. It is a medium-sized warbler with a brown, streaked back and wings and a distinct pale supercilium. Sedge warblers are migratory, crossing the Sahara to get from their European and Asian breeding grounds to spend winter in Africa. The male's song is composed of random chattering phrases and can include mimicry of other species. The sedge warbler is mostly insectivorous.
Radde's warbler is a leaf warbler which breeds in Siberia. This warbler is strongly migratory and winters in Southeast Asia. The genus name Phylloscopus is from Ancient Greek phullon, "leaf", and skopos, "seeker". The specific schwarzi commemorates German astronomer Ludwig Schwarz (1822–1894).
The western Bonelli's warbler is a warbler in the leaf warbler genus Phylloscopus. It was formerly regarded as the western subspecies of a wider "Bonelli's warbler" species, but as a result of modern taxonomic developments, they are now usually considered to be two species:
The Eastern Bonelli's warbler, sometimes known as Balkan warbler, is a "warbler" in the leaf warbler genus Phylloscopus. It was formerly regarded as the eastern subspecies of a wider "Bonelli's warbler" species, but as a result of modern taxonomic developments, they are now usually considered to be two species:
The Eurasian scops owl, also known as the European scops owl or just scops owl, is a small owl in the typical owl family Strigidae. Its breeding range extends from southern Europe eastwards to southern Siberia and the western Himalayas. It is migratory, wintering in Africa south of the Sahara.
The eastern crowned warbler is a species of Old World warbler in the family Phylloscopidae. It inhabits boreal and temperate forests in the east Palearctic.