Lifespan: The recorded longest lifespan is 12 years.
Breeding: The season lasts from April to the end of June. The pair bond usually lasts for life. This species is territorial and a solitary breeder; the territory is usually clearly defined in early February and defended from outside birds. Nests are often built in tree holes or artificial cavities such as metal road signs or walls. In Europe, nests contain 7-13 eggs and incubation takes up 12 to16 days. The fledglings are fed by both parents.
Appearance: The Eurasian Blue Tit is smaller than the House Sparrow. Its crown is blue, and the male has a white forehead, cheeks and eyebrows. The wings and tail are blue, and there is a white bar on the wings. The back is grey-green with a whitish spot on the back of the neck. The underside is yellow and a dimly blackish stripe runs along the chest. The bill is dark, the legs dark grey and the iris brown. The female is lighter in colour. The young have a yellowish-brown back and yellow cheeks. Immediately after hatching out, the fledglings have short and sparse grey-white down on their head and shoulders. Their mouth is orange-red.