Eurasian Tree Sparrow, gorrión molinero

The Eurasian Tree Sparrow is 12.5–14 cm long, with a wingspan of about 21 cm and a weight of 24 g, 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, and the bill is lead-blue in summer, becoming almost black in winter.

The Tree Sparrow is a predominantly seed and grain eating bird which feeds on the ground in flocks, often with House Sparrows, finches, or buntings. It eats weed seeds, such as chickweeds and goosefoot, spilled grain, and it may also visit feeding stations, especially for peanuts. It will also feed on invertebrates, especially during the breeding season when the young are fed mainly on animal food; it takes insects, woodlice, millipedes, centipedes, spiders and harvestmen.