Blue tit

The blue tit (Parus caeruleus) is one of the most popular and welcome British garden birds, not only for its attractiveness but its acrobatic displays on bird feeders of all kinds.


Appearance

Blue tits are small birds, around 11 or 12 centimetres (4 to 5 inches) in length. Their colouring is very distinctive, with yellow underparts, green upperparts, white faces (surrounded by a thin black stripe, and a black bar fore and aft of the eye which gives them something of a “highwayman’s mask”), and blue on the crown of the head, wings and tail. Males and females have similar plumage. Young birds are much greener, especially on the underparts. As with most tits, the blue tit has a fairly long tail that is used for balancing when the bird is hanging on to thin twigs or the wires of a bird feeder.


Behaviour

The blue tit is a woodland bird that has adapted to the presence of man wonderfully well, being present in gardens and parks in towns and cities as well as rural areas. Their food includes insects, seeds, nuts and fruit, much of which is in short supply in winter months. They are therefore frequent visitors to bird tables and provide much entertainment for householders who hang pieces of fat on strings or peanuts in wire feeders. The blue tit thinks nothing of hanging upside down to get at the food.

The blue tit has a pleasant, high-pitched song that incorporates trills and repeated notes. The flight can appear weak and fluttery, and blue tits are happy to hop along the ground rather than fly.


Breeding

Blue tits are frequent occupiers of nest boxes during the breeding season. Pairs start to search for suitable nest sites from early April and a nest box hanging on a wall makes an excellent substitute for a hole in a tree. They will build a nest in any small cavity that presents itself, and gardeners have found blue tits nesting in all sorts of odd corners.

The nest consists of moss, lined with feathers and soft hairs. A clutch of up to 16 eggs is laid, with the female bird doing all the incubating, for up to 14 days, while the male brings food to her at the nest. Both birds feed the young with a constant supply of insects and caterpillars, which can be hard work if most of the chicks thrive. The young birds fledge at around 20 days but are still fed by their parents for a short time longer.

If the food supply is good, the adult birds may raise a second brood in July, but this is unusual.

© John Welford