Leaf warbler

Leaf warblers are small insectivorous passerine birds belonging to the genus Phylloscopus.

Leaf warblers were formerly included in the Old World warbler family but are now considered to belong to the family Phylloscopidae, introduced in 2006. The family originally included the genus Seicercus, but all species have been moved to Phylloscopus in the most recent classification. Leaf warblers are active, constantly moving, often flicking their wings as they glean the foliage for insects along the branches of trees and bushes. They forage at various levels within forests, from the top canopy to the understorey. Most of the species are markedly territorial both in their summer and winter quarters. Most are greenish or brownish above and off-white or yellowish below. Compared to some other "warblers", their songs are very simple. Species breeding in temperate regions are usually strongly migratory.



Description
The species are of various sizes, often green-plumaged above and yellow below, or more subdued with greyish-green to greyish-brown colours, varying little or not at all with the seasons. The tails are not very long and contain 12 feathers (unlike the similar Abroscopus species, which have 10 tail feathers). Many species are more easily identified by their distinctive songs than their dull plumage. These are very small passerines with adult body masses that can vary from 3.5 to 17 g and in some cases, such as the Chinese leaf warbler, are among the lightest passerines anywhere. Several of the larger species are similar in size including the large-billed leaf warbler, Radde's warbler and the pale-legged leaf warbler. Total length can vary from 9 to 14.5 cm.

Distribution and habitat
Its members occur in Eurasia, ranging into Wallacea and Africa with one species, the Arctic warbler, breeding as far east as Alaska. Many of the species breed at temperate and high latitudes in Eurasia and migrate substantial distances to winter in southeastern Asia, India, or Africa. One example is Tickell's leaf warbler, which breeds in scrub at high elevation in the Himalayas and on the Tibetan Plateau and then moves down-slope and south to winter in the Himalayan foothills of India and Burma. Most live in forest and scrub and many are canopy or sub-canopy dwellers.

Behavior and ecology
The family Phylloscopidae comprises many small tree-loving warbler species that feed by gleaning insects from leaves or catching food on the wing.

Taxonomy
The genus Phylloscopus was introduced by the German zoologist Friedrich Boie in 1826 to accommodate a single species, the willow warbler, which is therefore considered as the type species. The name combines the Ancient Greek phullon meaning "leaf" and skopos meaning "seeker" (from skopeo, "to watch"). Phylloscopus is the only genus placed in the family Phylloscopidae that was introduced in 2006 by the Swedish ornithologist Per Alström and coworkers.

The genus contains 81 species: Of these, eleven species were formerly placed in the genus Seicercus, but a 2018 molecular phylogeny study indicated that the genus Seicercus is a synonym of Phylloscopus, leaving the family Phylloscopidae with a single genus, Phylloscopus.

Two birds were described in 2020 but have not yet been recognised as species by the International Ornithologists' Union. The alpine leaf warbler, Phylloscopus occisinensis, was reclassified as conspecific with Tickell's leaf warbler (P. affinis) by the IOC, but other authorities such as eBird still consider it distinct.
 * Wood warbler, Phylloscopus sibilatrix
 * Western Bonelli's warbler, Phylloscopus bonelli
 * Eastern Bonelli's warbler, Phylloscopus orientalis
 * Buff-barred warbler, Phylloscopus pulcher
 * Ashy-throated warbler, Phylloscopus maculipennis
 * Hume's leaf warbler, Phylloscopus humei
 * Yellow-browed warbler, Phylloscopus inornatus
 * Brooks's leaf warbler, Phylloscopus subviridis
 * Chinese leaf warbler, Phylloscopus yunnanensis
 * Lemon-rumped warbler, Phylloscopus chloronotus
 * Sichuan leaf warbler, Phylloscopus forresti
 * Gansu leaf warbler, Phylloscopus kansuensis
 * Pallas's leaf warbler, Phylloscopus proregulus
 * Tytler's leaf warbler, Phylloscopus tytleri
 * Yellow-streaked warbler, Phylloscopus armandii
 * Radde's warbler, Phylloscopus schwarzi
 * Sulphur-bellied warbler, Phylloscopus griseolus
 * Tickell's leaf warbler, Phylloscopus affinis (includes the Alpine leaf warbler, P. a. occisinensis)
 * Smoky warbler, Phylloscopus fuligiventer
 * Dusky warbler, Phylloscopus fuscatus
 * Plain leaf warbler, Phylloscopus neglectus
 * Buff-throated warbler, Phylloscopus subaffinis
 * Willow warbler, Phylloscopus trochilus
 * Mountain chiffchaff, Phylloscopus sindianus
 * Canary Islands chiffchaff, Phylloscopus canariensis
 * Eastern Canary Islands chiffchaff, Phylloscopus canariensis exsul (extinct: 1986?)
 * Western Canary Islands chiffchaff, Phylloscopus canariensis canariensis
 * Common chiffchaff, Phylloscopus collybita
 * Iberian chiffchaff, Phylloscopus ibericus
 * Eastern crowned warbler, Phylloscopus coronatus
 * Ijima's leaf warbler, Phylloscopus ijimae
 * Philippine leaf warbler, Phylloscopus olivaceus
 * Lemon-throated leaf warbler, Phylloscopus cebuensis
 * Yellow-throated woodland warbler, Phylloscopus ruficapilla
 * Brown woodland warbler, Phylloscopus umbrovirens
 * Red-faced woodland warbler, Phylloscopus laetus
 * Laura's woodland warbler, Phylloscopus laurae
 * Black-capped woodland warbler, Phylloscopus herberti
 * Uganda woodland warbler, Phylloscopus budongoensis
 * White-spectacled warbler, Phylloscopus intermedius – (previously Seicercus affinis)
 * Grey-cheeked warbler, Phylloscopus poliogenys – (previously placed in Seicercus)
 * Green-crowned warbler, Phylloscopus burkii – (previously placed in Seicercus)
 * Grey-crowned warbler, Phylloscopus tephrocephalus – (previously placed in Seicercus)
 * Whistler's warbler, Phylloscopus whistleri – (previously placed in Seicercus)
 * Bianchi's warbler, Phylloscopus valentini – (previously placed in Seicercus)
 * Alström's warbler, Phylloscopus soror – (first described in 1999; previously placed in Seicercus)
 * Martens's warbler, Phylloscopus omeiensis – (first described in 1999; previously placed in Seicercus)
 * Green warbler, Phylloscopus nitidus
 * Two-barred warbler, Phylloscopus plumbeitarsus
 * Greenish warbler, Phylloscopus trochiloides
 * Emei leaf warbler, Phylloscopus emeiensis
 * Large-billed leaf warbler, Phylloscopus magnirostris
 * Sakhalin leaf warbler, Phylloscopus borealoides
 * Pale-legged leaf warbler, Phylloscopus tenellipes
 * Japanese leaf warbler, Phylloscopus xanthodryas
 * Kamchatka leaf warbler, Phylloscopus examinandus
 * Arctic warbler, Phylloscopus borealis
 * Chestnut-crowned warbler, Phylloscopus castaniceps – (previously placed in Seicercus)
 * Sunda warbler, Phylloscopus grammiceps – (previously placed in Seicercus)
 * Yellow-breasted warbler, Phylloscopus montis – (previously placed in Seicercus)
 * Limestone leaf warbler, Phylloscopus calciatilis – (first described in 2010)
 * Sulphur-breasted warbler, Phylloscopus ricketti
 * Yellow-vented warbler, Phylloscopus cantator
 * Western crowned warbler, Phylloscopus occipitalis
 * Blyth's leaf warbler, Phylloscopus reguloides
 * Claudia's leaf warbler, Phylloscopus claudiae
 * Hartert's leaf warbler, Phylloscopus goodsoni
 * Kloss's leaf warbler, Phylloscopus ogilviegranti – (formerly considered as a subspecies of Davison's leaf warbler)
 * Hainan leaf warbler, Phylloscopus hainanus
 * Davison's leaf warbler, Phylloscopus intensior – (previously white-tailed leaf warbler, Phylloscopus davisoni)
 * Grey-hooded warbler, Phylloscopus xanthoschistos
 * Mountain leaf warbler, Phylloscopus trivirgatus
 * Negros leaf warbler, Phylloscopus nigrorum
 * Timor leaf warbler, Phylloscopus presbytes
 * Flores leaf warbler, Phylloscopus floresianus – (formerly considered as a subspecies of the Timor leaf warbler)
 * Rote leaf warbler, Phylloscopus rotiensis (first described in 2018)
 * Makira leaf warbler, Phylloscopus makirensis
 * Sulawesi leaf warbler, Phylloscopus nesophilus – (formerly considered as a subspecies of Lompobattang leaf warbler)
 * Lompobattang leaf warbler, Phylloscopus sarasinorum
 * Kolombangara leaf warbler, Phylloscopus amoenus
 * Island leaf warbler, Phylloscopus poliocephalus
 * Numfor leaf warbler, Phylloscopus maforensis
 * Biak leaf warbler, Phylloscopus misoriensis
 * Peleng leaf warbler, Phylloscopus suaramerdu
 * Taliabu leaf warbler, Phylloscopus emilsalimi