Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. They are not closely related to the New World warblers. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the cisticolas into Cisticolidae and the kinglets into Regulidae. In the past ten years they have been the subject of much research and many species are now placed into other families, including the Acrocephalidae, Cettiidae, Phylloscopidae, and Megaluridae. In addition some species have been moved into existing families or have not yet had their placement fully resolved. A smaller number of warblers, together with some babblers formerly placed in the family Timaliidae and the parrotbills, are retained in a much smaller family Sylviidae.
Leaf warblers are small insectivorous passerine birds belonging to the genus Phylloscopus.
The willow warbler 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.
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 Arctic warbler is a widespread leaf warbler in birch or mixed birch forest near water throughout its breeding range in Fennoscandia and the northern Palearctic. It has established a foothold in North America, breeding in Alaska. This warbler is strongly migratory; the entire population winters in southeast Asia. It therefore has one of the longest migrations of any Old World insectivorous bird.
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.
Hume's leaf warbler or Hume's warbler is a small leaf warbler which breeds in the mountains of inner Asia. This warbler is migratory and winters mainly in India.
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:
Tickell's leaf warbler is a leaf warbler found in Asia in the countries of Bangladesh, Bhutan, China, India, Myanmar, Nepal, Pakistan and Thailand. The species has a yellowish underside and supercilium. Like other leaf warblers it feeds mostly on insects by gleaning and short sallies. An active bird, it prefers the canopy and low shrubbery and can be difficult to track as it moves actively from branch to branch, acrobatically exploring the underside of leaves and twigs. The clear yellowish undersides and lack of a wing bar can be used to tell it apart from similar species. It has slim dark legs with largely pale lower mandible and grayish wing panel.
The Chinese leaf warbler is a species of Old World warbler in the family Phylloscopidae. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical high-altitude shrubland. It is found only in China.
Davison's leaf warbler or the white-tailed leaf warbler, is a species of leaf warbler. It was formerly included in the "Old World warbler" assemblage.
The Emei leaf warbler is a species of leaf warbler. It was formerly included in the "Old World warbler" assemblage.
The white-spectacled warbler is a species of leaf warbler in the family Phylloscopidae. It is found in Asia from the eastern Himalayas to south-eastern China and southern Vietnam. Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montane forests. It was formerly included in the Old World warbler family, Sylviidae.
The green-crowned warbler is a species of leaf warbler. It was formerly included in the "Old World warbler" assemblage.
Alström's warbler, or the plain-tailed warbler, is a species of Old World warbler in the family Phylloscopidae. It was first described in 1999. It breeds only in China and winters as far as Thailand, Laos, Cambodia and Vietnam. Its natural habitat is temperate forests.
Whistler's warbler is a species of leaf warbler. It was formerly included in the "Old World warbler" assemblage.
The limestone leaf warbler is a species of warbler in the family Phylloscopidae. When this species was first seen, beginning in 1994, it was mistaken for the similar sulphur-breasted warbler. It is smaller than the sulphur-breasted warbler, and has more rounded wings. The plumage is almost identical, with comparisons showing only a slightly colder yellow below and a greyer tinge above. Although smaller, the bill is proportionally larger than that of the sulphur-breasted warbler. Accurate measurements are not available; the holotype has a wing length of 5.2 cm (2.0 in); the paratype a tail length of 3.7 cm (1.5 in) and a bill length of 1.39 cm (0.55 in). The species is known to occur in northern Vietnam and Laos, and potentially also occurs in southern China as well. The species name, calciatilis, means "dwelling on limestone", which along with its common name is a reference to its natural habitat, which is broadleaved evergreen and semi-evergreen forest growing around limestone karst mountains. The bare-faced bulbul, described in 2009, was found in the karst of the same region.
