Eurasian Tree Sparrow

The Eurasian tree sparrow (Passer montanus) is a charming passerine bird, easily recognized by its rich chestnut crown and nape, and a distinctive black patch on each pure white cheek. Both sexes are similarly adorned, and the juveniles mirror the adults, albeit with slightly duller hues. This species is somewhat smaller than the closely related house sparrow, and its size is approximately 12.5–14 cm in length, with a wingspan of about 21 cm.

Identification Tips

To identify the Eurasian tree sparrow, look for the kidney-shaped black ear patch on each white cheek, the black chin and throat, and the light brown upperparts streaked with black. The wings bear two narrow white bars, and the legs are pale brown. The bill is lead-blue in summer, darkening almost to black in winter. Unlike the house sparrow, there is no sexual dimorphism in plumage, making both males and females equally easy to identify.

Habitat

In Europe, the Eurasian tree sparrow is typically found in lightly wooded open countryside, while in eastern Asia, it is more common in urban settings. It prefers nesting in natural cavities, holes in buildings, or even the abandoned nests of other large birds. This species is not typically found in mountainous regions, despite its scientific name suggesting otherwise.

Distribution

The Eurasian tree sparrow has a broad distribution across temperate Eurasia and Southeast Asia, and it has been introduced to other regions such as the United States. Its range extends from Europe across Asia to the Lena River and south to the northern regions of Turkey, the Caucasus, Kazakhstan, Mongolia, and North Korea.

Behaviour

The Eurasian tree sparrow is a sociable bird, often seen in flocks. It is sedentary in most of its range, but northern populations may migrate southward in winter. This species is known for its untidy nests and can breed in a variety of locations, from tree holes to urban structures.

Song & Calls

The Eurasian tree sparrow does not have a true song but communicates with a series of excited "tschip" calls during courtship and other monosyllabic chirps for social interactions. Its flight call is a harsh "teck."

Breeding

Breeding maturity is reached within a year, and the typical clutch consists of five or six eggs. Both parents incubate the eggs for about 12-13 days, and the chicks fledge after 15-18 days. The species may raise two or three broods each year.

Similar Species

The Eurasian tree sparrow can be confused with the house sparrow, but the latter has a grey, not brown, crown and lacks the distinctive face pattern of the tree sparrow.

Diet and Feeding

Primarily a seed and grain eater, the Eurasian tree sparrow forages on the ground in flocks. During the breeding season, it also consumes invertebrates to feed its young. It is known to visit feeding stations, particularly for peanuts.

Conservation Status

With an extensive range and large population, the Eurasian tree sparrow is classified as Least Concern globally. However, there have been significant declines in western European populations due to changes in farming practices, such as increased use of herbicides and loss of winter stubble fields.