Sparrow

Sparrows are a family of small passerine birds, Passeridae. They are also known as true sparrows, or Old World sparrows, names also used for a particular genus of the family, Passer. They are distinct from both the American sparrows, in the family Emberizidae, and from a few other birds sharing their name, such as the Java sparrow of the family Estrildidae. Many species nest on buildings, and the house and Eurasian tree sparrows in particular inhabit cities in large numbers, so sparrows may be the most familiar of all wild birds. They are primarily seed-eaters, though they also consume small insects. Some species scavenge for food around cities and, like gulls or rock doves, will happily eat virtually anything in small quantities. 

Sparrows are physically similar to other seed-eating birds, such as finches, but have a vestigial dorsal outer primary feather and an extra bone in the tongue. This bone, the preglossale, helps stiffen the tongue when holding seeds. Other adaptations towards eating seeds are specialised bills and elongated and specialised alimentary canals.The sparrows are indigenous to Europe, Africa and Asia. In the Americas, Australia, and other parts of the world, settlers imported some species which quickly naturalised, particularly in urban and degraded areas.

Sparrows are generally social birds, with many species breeding in loose colonies and most species occurring in flocks during the non-breeding season. The great sparrow is an exception, breeding in solitary pairs and remaining only in small family groups in the non-breeding season. Most sparrows form large roosting aggregations in the non-breeding seasons that contain only a single species (in contrast to multi-species flocks that might gather for foraging). Sites are chosen for cover and include trees, thick bushes and reed beds.