Birds in the Family Passeridae are known as true sparrows or Old World sparrows. They are distinct from both the American or New World sparrows in the family Emberizidae. Many species nest on buildings and 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.
Generally, sparrows are small, plump, brown-grey birds with stubby and powerful beaks. The differences between sparrow species can be subtle. 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. There is one genus and one species of the Family Passeridae known to occur in Peru. Photo: House Sparrow.