The Eurasian Tree Sparrow (Passer montanus) has a rich chestnut crown and nape, and a black patch on each pure white cheek. The sexes are similarly plumaged, but the 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 in the United States, where it is known as the Eurasian Tree Sparrow or German Sparrow in an effort 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. The Eurasian Tree Sparrow builds an untidy nest in a natural cavity, a hole in a building or the large nest of a magpie or stork. The typical clutch is five or six eggs that hatch in less than two weeks. This sparrow feeds mainly on seeds, but invertebrates are also consumed, particularly during the breeding season. The Eurasian Tree Sparrow appears widespread in the towns and cities of eastern Asia, but in Europe it is a bird of lightly wooded open countryside, with the House Sparrow breeding in the more urban areas.