The tree sparrow is smaller and more active than the house sparrow and can be identified by its chestnut crown. It is unusual within its genus in that there is no difference between the sexes. There has been a large decline in the UK population since the 1970s, partly due to changes in farming practices. However, data suggests that numbers are slowly starting to recover although there are still fewer than 10 percent of those present in the 1960s.
Breeding birds: 200,000 territories
Tree sparrows have brown or reddish-brown upperparts with black streaks on the back, and the brown wings have two distinctive narrow white wing bars. The underparts are buff, the upper tail is brown while the undertail coverts are grey-brown.
On the head the crown, forehead and nape are chestnut brown and the chin and throat are black. The cheeks are white smudged with black and there are black patches around the eyes. The cone-shaped bill is lead-blue in the summer, turning black in the winter, the eyes are dark brown, and the legs and feet are pinkish-brown. Males and females look similar.
Juvenile tree sparrows resemble adults but are duller overall.
Tree sparrows nest in loose colonies or in solitary pairs. They build their nests in holes in trees, cliffs, or buildings. They will also use the old nests of magpies and other larger birds. The male collects the material and the female builds the nest which is made from twigs and leaves and lined with down.
Tree sparrows lay 2-9 smooth, glossy, white or pale grey eggs with darker markings. Both male and female incubate the eggs for 11-14 days. Chicks are altricial and are fed by both parents. They fledge at 12-15 days after hatching and reach sexual maturity at 1 year. They produce 2 or 3 broods a year.
Tree sparrows eat mainly seeds, but will also supplement their diet with small insects, caterpillars, and beetles, particularly during breeding season. They will sometimes form flocks with house sparrows, finches, and buntings. Tree sparrows will also visit gardens in search of food from bird feeders.
Tree sparrows are found in hedgerows, the edges of open woodland and orchards. They can be found mainly in the south and east of England and the Midlands although there are scarce populations in the far north and west.
Although tree sparrows are rarer in Britain than house sparrows, they have a much larger worldwide distribution and are found throughout most of Europe and Asia including Indonesia and Japan.