It is found in temperate and subarctic deciduous or mixed woodlands, scrub and marshes. It is resident, and most birds do not migrate. It nests in a tree hole, laying about 10 eggs. The bird is a close sitter, hissing and biting when disturbed. Its food is insects and seeds.
This 12–13 cm bird is unmistakable. The head, tail corners, wing bars and underparts are white. There is a dark line through the eye, and the upperparts are blue.
This is the eastern counterpart of the common Eurasian blue tit. It will hybridise with that species, but the offspring usually show a blue crown, rather than the white of azure tit. The calls are similar to blue tit, calling dee, dee, dee or a scolding churr. The song is a tsi-tsi-tshurr-tsi-tsi-tshurr, which has been described as intermediate between blue tit and crested tit.
For many years the azure tit was known as Parus cyanus. In 2005, analysis of the mtDNA cytochrome b sequences of the Paridae indicated that Cyanistes was an early offshoot from the lineage of other tits, and more accurately regarded as a genus rather than a subgenus of Parus.
- BirdLife International (2013). "Parus cyanus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Gill, Frank B.; Beth Slikas and Frederick H. Sheldon (2005). "Phylogeny of titmice (Paridae): II. Species relationships based on sequences of the mitochondrial cytochrome-b gene". Auk. 122 (1): 121–143. doi:10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2.
- "Cyanistes flavipectus". Avibase.