Thewillow tit (Poecile montanus) is apasserinebird in thetit family, Paridae. It is a widespread and common resident breeder throughout temperate and subarctic Europe and across thePalearctic. The plumage is grey-brown and off-white with a black cap and bib. It is more of aconifer specialist than the closely relatedmarsh tit, which explains its breeding much farther north. It is resident, and most birds do notmigrate.
Poecile was at one time treated as a subgenus within the genusParus butmolecular taxonomic analysis, using both nuclear andmitochondrial genes, supportsPoecile as a distinct clade. WithinPoecile, most of the Old World species (including the willow tit) form a separate clade from the New World chickadees.[6] The taxonomic analysis has shown that the willow tit issister to theCaspian tit (Poecile hyrcanus).[6][7]
P. m. affinisPrzevalski, 1876 – central north China
P. m. stoetzneri (Kleinschmidt, 1921) – northeast China
TheSichuan tit (Poecile weigoldicus) was formerly treated as a subspecies of the willow tit. It was promoted to species status based on a 2002 phylogenetic analysis that compared DNA sequences from themitochondrial cytochrome-b gene.[9][10] The singlelocus results were later confirmed by a larger multi-locus analysis published in 2017.[7]
The willow tit is 11.5 cm (4.5 in) in length, has a wingspan of 17–20.5 cm (6.7–8.1 in) and weighs around 11 g (0.39 oz).[11] It has a large head, a thin bill, a long dull black cap that descends to themantle and a black bib. The sides of the face are white, the back is grey-brown and the underparts are buff. The sexes are similar in appearance.[12]
In the east of its range it is much paler than marsh tit, but as one goes west the various races become increasingly similar, so much so that it was not recognised as a breeding bird in Great Britain until the end of the 19th century, despite being widespread.
The willow tit is distinguished from the marsh tit by a sooty brown instead of a glossy blue black cap; the general colour is otherwise similar, though the under parts are more buff and the flanks distinctly morerufous; the pale buff edgings to the secondaries form a light patch on the closed wing. The feathers of the crown and the black bib under the bill are longer, but this is not an easily noticed character.[12]
The commonest call is a nasalzee,zee, zee, but the notes of the bird evidently vary considerably. Occasionally a double note,ipsee, ipsee, is repeated four or five times.[13]
The willow tit excavates its own nesting hole, even piercing hard bark; this is usually in a rotten stump or in a tree, more or less decayed. Most nests are cups offelted material, such as fur, hair and wood chips, butfeathers are sometimes used. The eggs are laid daily. The clutch is typically between six and nine eggs. The eggs have a white background and are marked with red-brown speckles and spots which are often concentrated at the broader end. They measure around 15.8 mm × 12.3 mm (0.62 in × 0.48 in) and weigh 1.2 g (0.042 oz). The eggs are incubated by the female alone and hatch after 13–15 days. The chicks are then cared for and fed by both parents but only the female broods the young. The nestlings fledge after 17–20 days. Only a single brood is raised each season.[14]
In a study usingring-recovery data carried out in northern Finland, the survival rate for juveniles for their first year was 0.58, and the subsequent adult annual survival rate was 0.64.[15] For birds that survive the first year the typical lifespan is thus only three years.[16] The maximum recorded age is 11 years; this has been recorded for a bird in Finland and for another nearNottingham in England.[17][18]
The willow tit has an extremely large range with an estimated population of between 175 and 253 million mature individuals. This large population appears to be slowly decreasing but the decline is not sufficiently rapid to approach the threshold of vulnerability. The species is therefore classed as ofleast-concern by theInternational Union for Conservation of Nature.[1] In contrast, the number in the United Kingdom declined by 83% between 1995 and 2017. There was also a contraction in the range.[20] The rapid decline is believed be due to three factors: habitat loss, competition for nest holes by other tits particularly blue tits, and nest predation by thegreat spotted woodpecker.[21][22][23] Over the same period, the number of great spotted woodpeckers increased fourfold.[20]
^abJohansson, Ulf S.; Ekman, Jan; Bowie, Rauri C. K.; Halvarsson, Peter; Ohlson, Jan I.; Price, Trevor D.; Ericson, Per G. P. (2013). "A complete multilocus species phylogeny of the tits and chickadees (Aves: Paridae)".Molecular Phylogenetics and Evolution.69 (3):852–860.Bibcode:2013MolPE..69..852J.doi:10.1016/j.ympev.2013.06.019.PMID23831453.
^abTritsch, Christian; Martens, Jochen; Sun, Yue-Hua; Heim, Wieland; Strutzenberger, Patrick; Päckert, Martin (2017). "Improved sampling at the subspecies level solves a taxonomic dilemma – A case study of two enigmatic Chinese tit species (Aves, Passeriformes, Paridae,Poecile)".Molecular Phylogenetics and Evolution.107:538–550.Bibcode:2017MolPE.107..538T.doi:10.1016/j.ympev.2016.12.014.PMID27965081.
^Salzburger, Walter; Martens, Jochen; Nazarenko, Alexander A.; Sun, Yua-Hue; Dallinger, Reinhard; Sturmbauer, Christian (2002). "Phylogeography of the Eurasian Willow Tit (Parus montanus) based on DNA sequences of the mitochondrial cytochromeb gene".Molecular Phylogenetics and Evolution.24 (1):26–34.Bibcode:2002MolPE..24...26S.doi:10.1016/S1055-7903(02)00266-X.PMID12128026.
^Gosler, A.G.; Clement, P. (2007)."Family Paridae (Tits and Chickadees)". In del Hoyo, J.; Elliott, A.; Sargatal, J. (eds.).Handbook of the Birds of the World. Vol. 12: Picathartes to Tits and Chickadees. Barcelona, Spain: Lynx Edicions. pp. 662–750 [712–713].ISBN978-84-96553-42-2.
^Lewis, Alex J.G.; Amar, Arjun; Chormonond, Elisabeth C.; Stewort, Finn R.P. (2009)."The decline of the Willow Tit in Britain"(PDF).British Birds.102:386–393. Archived fromthe original(PDF) on 2021-09-02. Retrieved2023-02-14.
Cramp, Stanley; Perrins, C.M., eds. (1993). "Parus montanus Willow Tit".Handbook of the Birds of Europe the Middle East and North Africa. The Birds of the Western Palearctic. Vol. VII: Flycatchers to Strikes. Oxford: Oxford University Press. pp. 168–186.ISBN978-0-19-857510-8.
