The Eurasian tree sparrow is similar to the house sparrow and may be missed when it appears in mixed flocks. Adult upperparts are reddish brown with a chocolate brown head. The eye line is black, and the cheek is white with a black spot in the center. Underparts are grayish, with a brownish wash on the sides and flanks. The black bib is much smaller than on the house sparrow. Song is higher pitched than the house sparrow's and is more metallic. Call is a hard tik tik given in flight, or a chit-chup.