Chickadee

The genus includes the following fifteen species: {| class="wikitable" |- ! Image !! Common name !! Scientific name !! Distribution |- | || White-browed tit || Poecile superciliosus|| central China and Tibet. |- | || Sombre tit || Poecile lugubris|| southeast Europe and southwest Asia |- | || Grey-headed chickadee (North American name) or Siberian tit (European name) || Poecile cinctus|| subarctic Scandinavia and northern Asia, and also into North America in Alaska and the far northwest of Canada |- | || Chestnut-backed chickadee || Poecile rufescens|| Pacific Northwest of the United States and western Canada, from southern Alaska to southwestern California |- | || Boreal chickadee ||Poecile hudsonicus|| Canada, Alaska, and northernmost portions of the lower 48 United States |- | || Mexican chickadee || Poecile sclateri|| Mexico |- | || Carolina chickadee || Poecile carolinensis|| United States from New Jersey west to southern Kansas and south to Florida and Texas |- | || Black-capped chickadee || Poecile atricapillus|| Across North America, from New England to Newfoundland in the east, and from Washington to Alaska in the west |- | || Mountain chickadee || Poecile gambeli|| western United States |- | || Père David's tit || Poecile davidi|| central China in southern Gansu, western Hubei, southern Shaanxi and Sichuan |- | || Black-bibbed tit || Poecile hypermelaenus||central and eastern China to southeast Tibet and western Myanmar. |- | || Marsh tit || Poecile palustris|| temperate Europe and northern Asia |- | || Sichuan tit || Poecile weigoldicus|| central China |- | || Caspian tit || Poecile hyrcanus|| northern Iran, just extending into Azerbaijan. |- | || Willow tit || Poecile montanus|| temperate and subarctic Europe and northern Asia |- |} All the species are roughly similar in size, ranging from 11–15 cm, with marsh, willow, and black-bibbed tits marginally the smallest (11–13 cm), and sombre tit and mountain chickadee marginally the largest (13–15 cm). 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.

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.

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.

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.