Phylloscopus trochilus

Phylloscopus trochilus

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Archosauromorpha
Cladus: Crurotarsi
Divisio: Archosauria
Cladus: Avemetatarsalia
Cladus: Ornithodira
Subtaxon: Dinosauromorpha
Cladus: Dinosauriformes
Cladus: Dracohors
Cladus: Dinosauria
Cladus: Saurischia
Cladus: Eusaurischia
Subordo: Theropoda
Cladus: Neotheropoda
Cladus: Averostra
Cladus: Tetanurae
Cladus: Avetheropoda
Cladus: Coelurosauria
Cladus: Tyrannoraptora
Cladus: Maniraptoromorpha
Cladus: Maniraptoriformes
Cladus: Maniraptora
Cladus: Pennaraptora
Cladus: Paraves
Cladus: Eumaniraptora
Cladus: Avialae
Infraclassis: Aves
Cladus: Avebrevicauda
Cladus: Pygostylia
Cladus: Ornithothoraces
Cladus: Ornithuromorpha
Cladus: Carinatae
Parvclassis: Neornithes
Cohors: Neognathae
Cladus: Neoaves
Cladus: Telluraves
Cladus: Australaves
Ordo: Passeriformes
Subordo: Passeri
Infraordo: Passerida
Superfamilia: Sylvioidea

Familia: Phylloscopidae
Genus: Phylloscopus
Species: Phylloscopus trochilus
Subspecies: P. t. acredula - P. t. trochilus - P. t. yakutensis
Name

Phylloscopus trochilus (Linnaeus, 1758)
Synonyms

Motacilla trochilus (protonym)

References

Linnaeus, C. 1758. Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio Decima, Reformata. Tomus I. Holmiæ (Stockholm): impensis direct. Laurentii Salvii. 824 pp. DOI: 10.5962/bhl.title.542 BHL p. 188 BHL Reference page.

Vernacular names
Afrikaans: Hofsanger
العربية: دخلة الصفصاف, ذعرة الصفصاف, نقشارة الصفصاف
asturianu: Pioyín de Ríu
azərbaycanca: Bahar yarpaqgüdəni
башҡортса: Төйөт
беларуская: Пячураўка-будаўнічок
български: Брезов певец
brezhoneg: Puig-haleg
català: Mosquiter de passa
čeština: Budníček větší
Cymraeg: Telor yr Helyg
dansk: Løvsanger
Deutsch: Fitis
Ελληνικά: Θαμνογιαννούδι
emiliàn e rumagnòl: Becafigh
English: Willow Warbler
Esperanto: Fitiso
español: Mosquitero musical
eesti: Salu-lehelind
euskara: Txio hori
suomi: Pajulintu
føroyskt: Leyvljómari
Nordfriisk: Letj fleegenbitjer
français: Pouillot fitis
Frysk: Lytse hôfsjonger
Gaeilge: Ceolaire Sailí
Gàidhlig: Crionag Ghiuthais
galego: Picafollas musical
Gaelg: Drean bane
עברית: עלווית אפורה
hrvatski: Brezov zviždak
magyar: Fitiszfüzike
հայերեն: Գարնանային Գեղգեղիկ (Garnanayin Geghgeghik)
íslenska: Laufsöngvari
italiano: Luì grosso
日本語: キタヤナギムシクイ (Kitayanagi mushi-kui)
ქართული: ყარანა-გაზაფხულა
қазақша: Кєктем сайрауығы
한국어: 연노랑눈솔새
kernowek: Telor helyk
Lëtzebuergesch: Fitis
Limburgs: Favet
lietuvių: Ankstyvoji pečialinda
latviešu: Vītītes ķauķis
македонски: Брезов пејач
монгол: Ногоон дуучшувуу
Malti: Vjolin Pastard
Nedersaksies: Lutje hofzinger
Nederlands: Fitis
norsk nynorsk: Lauvsongar
norsk: Løvsanger
Nouormand: Démouaîselle
polski: Piecuszek
português: Felosa-musical
rumantsch: Fegliarel musicant
română: Pitulicea fluierătoare
русский: Пеночка-весничка
sicilianu: Riiddu rossu
Scots: Muffie
davvisámegiella: Rievssatcizaš
srpskohrvatski / српскохрватски: Brezov zviždak
slovenčina: Kolibiarik spevavý
slovenščina: Severni kovaček
chiShona: Timba
shqip: Fishkëllyesi gushëverdhë
српски / srpski: Brezov zviždak
Sesotho: Pilipili-sa-mabelete
svenska: Lövsångare
Kiswahili: Kuchamsitu wa Ulaya, Kucha-mbuga
Türkçe: Söğütbülbülü
українська: Вівчарик весняний
Tiếng Việt: Chích liễu
isiXhosa: Unothoyi
中文: 欧柳莺, 歐亞柳鶯

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]
Taxonomy

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]

P. t. trochilus (Linnaeus, 1758). Breeds Europe (from the Pyrenees and Alps northward) except northern Scandinavia, winters west Africa.
P. t. acredula (Linnaeus, 1758). Breeds northern Scandinavia east to western Siberia, winters central Africa.
P. t. yakutensis (Ticehurst, 1935). Breeds eastern Siberia, winters eastern and southern Africa.

Description

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]
Behaviour

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:

October to March: wintering in sub-Saharan Africa.
Mid-March to mid-May: migrates and arrives in the breeding range.
Late April to August: breeding season, usually only one brood but rarely two.
August to October: migrates back to Africa.

Status and conservation
Egg, Collection Museum Wiesbaden, Germany

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]
References

BirdLife International. (2016). "Phylloscopus trochilus". IUCN Red List of Threatened Species. 2016: e.T22715240A87636348. doi:10.2305/IUCN.UK.2016-3.RLTS.T22715240A87636348.en. Retrieved 7 October 2021.
Hoyo, J. del; et al., eds. (2006). Handbook of the Birds of the World, vol. 11. Barcelona: Lynx Edicions. pp. 649. ISBN 84-87334-22-9.
Baker, Kevin (1997). Warblers of Europe, Asia and North Africa (Helm Identification Guides). Christopher Helm. pp. 256–259. ISBN 0-7136-3971-7.
Snow, D. W.; Perrins, C. M. (1998). The Birds of the Western Palearctic (Concise ed.). Oxford: Oxford University Press. ISBN 0-19-854099-X.
Linnaeus, Carl (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1 (10th ed.). Holmiae (Stockholm): Laurentii Salvii. p. 188.
Boie, Friedrich (1826). "Generalübersicht der ornithologischen Ordnungen Familien und Gattugen". Isis von Oken (in German). 19. col. 972.
Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2022). "Bushtits, leaf warblers, reed warblers". IOC World Bird List Version 12.1. International Ornithologists' Union. Retrieved 7 June 2022.
Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 221, 391. ISBN 978-1-4081-2501-4.
Yarrell, William (1843). A History of British Birds. London: John Van Voorst. pp. 302–306.
Lockwood, William Burley (1993) [1984]. The Oxford Dictionary of British Bird Names (2nd ed.). Oxford: Oxford University Press. p. 167. ISBN 978-0-19-866196-2.
Ageing and sexing (PDF) by Javier Blasco-Zumeta
RSPB Woodland Management For Birds – Willow Warbler