Similar to the house sparrow (Passer domesticus), the tree sparrow (Passer montanus) was not recognised as a separate species until 1713. Both sexes are similar, with a rich chestnut-brown head and nape, a clear black spot on white cheeks, and a white collar. The voice consists of various chirps and cheeps, which are of a higher pitch than those of the house sparrow
Tree sparrows feed mainly on plant matter, including seeds, buds, shoots, berries and flowers, they also take invertebrates such as grasshoppers, beetles and spiders when available. The young are fed entirely on invertebrates in their first week. The breeding season is between mid April and early August. The nest is built in holes, dense conifers or occasionally in old nests of larger birds. Two to three broods can be produced a year, each containing 2-7 eggs. The incubation duties are shared by both parents; after 11 to14 days the chicks hatch and fledging occurs after a further 15 to 20 days.