The
Eurasian tree sparrow (
Passer montanus) is a
passerine bird in the
sparrow family with a rich chestnut
crown and
nape, and a black patch on each pure white cheek. The sexes are similarly
plumaged, and young birds are a duller version of the adult. This sparrow breeds over most of temperate
Eurasia and
Southeast Asia, where it is known as the
tree sparrow, and it has been introduced elsewhere including the United States, where it is known as the Eurasian tree sparrow or
German sparrow to differentiate it from the native unrelated
American tree sparrow. Although several subspecies are recognised, the appearance of this bird varies little across its extensive range.