Eurasian Tree Sparrow

The Eurasian Tree Sparrow is 12.5–14 cm long, with a wingspan of about 21 cm and a weight of 24 g (0.86 oz),making it roughly 10% smaller than the House Sparrow. The adult's crown and nape are rich chestnut, and there is a kidney-shaped black ear patch on each pure white cheek; the chin, throat, and the area between the bill and throat are black. The upperparts are light brown, streaked with black, and the brown wings have two distinct narrow white bars. The legs are pale brown.
This sparrow is distinctive even within its genus in that it has no plumage differences between the sexes; the juvenile also resembles the adult, although the colours tend to be duller. Its contrasting face pattern makes this species easily identifiable in all plumages. the smaller size and brown, not grey, crown are additional differences from the male House Sparrow.Adult and juvenile Eurasian Tree Sparrows undergo a slow complete moult in the autumn, and show an increase in body mass despite a reduction in stored fat. The change in mass is due to an increase in blood volume to support active feather growth, and a generally higher water content in the body.