The long-tailed tit was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Parus caudatus.

[9] The long-tailed tit exhibits complex global variation with 17 races recognised,[10] divisible into three groups:[11] The silver-throated bushtit (Aegithalos glaucogularis) from eastern China was formerly considered conspecific but the plumage is distinctive and there are significant genetic differences.

They have three main calls, a single high pitched pit, a ‘triple trill’ eez-eez-eez, and a rattling schnuur.

The calls become faster and louder when the birds cross open ground or if an individual becomes separated from the group.

[15] The long-tailed tit is globally widespread throughout temperate Northern Europe and the Palearctic, into boreal Scandinavia and south into the Mediterranean zone.

[16] It inhabits deciduous and mixed woodland with a well-developed shrub layer, favouring edge habitats.

It can also be found in scrub, heathland with scattered trees, bushes and hedges, in farmland and riverine woodland,[11] parks and gardens.

The bird's year-round diet of insects and social foraging bias habitat choice in winter towards deciduous woodland, typically of oak, ash and locally sycamore species.

The nest is a flexible sac with a small, round entrance at the top, suspended either low in a gorse or bramble bush or high up in the forks of tree branches.

[22] From July to February, the non-breeding season, long-tailed tits form flocks of relatives and non-relatives, roosting communally.

[15] Since long-tailed tits are cooperative breeders, where opposite sex adult relatives are spatially clustered, they risk inbreeding fitness costs.

It has been shown that failed pairs split and help at the nests of male relatives,[22][25][26] recognition being established vocally.

This may be due to helpers having relatively poorer body conditions at the end of the breeding season, similar to pied kingfisher and white-winged chough.

[11] The IUCN, BirdLife International and The British Trust for Ornithology (BTO) all list the long-tailed tit as a ‘species of least concern’, currently under little or no threat and reasonably abundant.