Poecile is a genus of birds in the tit family Paridae. It contains 15 species, which are distributed across Europe, Asia, and North America; the European and Asian species are known as tits, and the North American species as chickadees. In the past, most authorities retained Poecile as a subgenus within the genus Parus, but treatment as a distinct genus, initiated by the American Ornithologists Union, is now widely accepted. This is supported by mtDNA cytochrome b sequence analysis.

The genus Poecile was described by the German naturalist Johann Jakob Kaup in 1829. Kaup included two species in the genus, marsh tit Poecile palustris and coal tit P. ater; the type species was subsequently designated as the marsh tit by English zoologist George Robert Gray in 1842 (with coal tit now in the genus Periparus). The name Poecile was derived by Kaup from the Ancient Greek adjective ποικίλος, poikilos ("multicolored"); the related word ποικιλίς, poikilis, is recorded by Aristotle as the name of a small bird, sometimes identified with the goldfinch. It had traditionally been treated as feminine, giving name endings such as cincta; however, this was not specified by Kaup, and under the ICZN the genus name must therefore be treated by default as masculine, giving name endings such as cinctus.

Species

The genus includes the following fifteen species:All the species are roughly similar in size, ranging from 11–15cm, with marsh, willow, and black-bibbed tits marginally the smallest (11–13cm), and sombre tit and mountain chickadee marginally the largest (13–15cm). The plumage pattern is also broadly similar across the genus, with a black or dark brown crown and bib, whitish or pale buffy cheeks, and whitish to buffy underparts. Two species (white-browed tit and mountain chickadee) differ in having a white supercilium. The back and wings are brown to grey-brown or reddish brown, in some with pale fringes on the secondary feathers.

Behaviour

Many species have alarm calls with a distinctive "chick-a-dee-dee-dee" format, which gives rise to the name 'chickadee'; the number of "dees" depends on the predator and the risk it poses, with more "dees" for high risk predators such as small owls.

Ecology

All are birds of mature woodlands and forests, often with a preference for old-growth habitats with plentiful tree cavities for nesting; many, but not all, readily adapt to human provision of food and nestboxes.

Several species, including Siberian, marsh and willow tits in Eurasia and mountain chickadee in North America, are food-caching birds. Siberian tit, living in the coldest environment, is the greatest hoarder, with individual birds storing up to half a million food items throughout each year for winter use. Mountain chickadees can hide as many as 80,000 individual seeds each, which they retrieve during the winter. Their ability to do so depends on their spatial memory of the locations. Birds that live in harsher conditions, where their ability to remember the location of food is more important, have been found to have better memory abilities, a larger hippocampus, and more neurons than chickadees that live in milder climates where food sources are easier to find without relying on memory.

In culture

The chickadee (specifically the black-capped chickadee P. atricapillus) is the official bird for the US state of Massachusetts, the Canadian province of New Brunswick, as well as the cities of Calgary, Alberta, and Regina, Saskatchewan. The chickadee is also the state bird of Maine, but a species has never been specified. A proposed bill in 2019 would have named the black-capped chickadee as the official species for Maine, but was unanimously voted down in committee. The de facto species for Maine remains the black-capped.

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