Old World sparrows are groups of small passerine birds forming the family Passeridae. They are also known as true sparrows, a name which is also used for a particular genus of the family Passer. They are distinct from both the New World sparrows of the family Passerellidae and from a few other birds such as the Java sparrow of the family Estrildidae sharing their name. Many species nest on buildings and the house and Eurasian tree sparrows, in particular, inhabit cities in large numbers. They are primarily seed-eaters, though they also consume small insects. Some species scavenge for food around cities and like pigeons or gulls, will eat small quantities of a diversity of items.
Description
Male house sparrow in Germany
Yellow-throated sparrow at Keoladeo National Park, India
Sparrow in Tharparkar, Sindh
Generally, Old World sparrows are small, plump, brown and grey birds with short tails and stubby, powerful beaks. The differences between sparrow species can be subtle. Members of this family range in size from the chestnut sparrow (Passer eminibey), at 11.4 centimetres (4.5 in) and 13.4 grams (0.47 oz), to the parrot-billed sparrow (Passer gongonensis), at 18 centimetres (7.1 in) and 42 grams (1.5 oz). Sparrows are physically similar to other seed-eating birds, such as finches, but have a vestigial dorsal outer primary wing feather and an extra bone in the tongue. This bone, the preglossale, helps stiffen the tongue when holding seeds. Other adaptations for eating seeds are specialised bills and elongated and specialised alimentary canals.
Taxonomy and systematics
A sparrow chick
The family Passeridae was introduced (as Passernia) by the French polymath Constantine Samuel Rafinesque in 1815. Under the classification used in the Handbook of the Birds of the World (HBW) main groupings of the sparrows are the true sparrows (genus Passer), the snowfinches (typically one genus, Montifringilla), and the rock sparrows (Petronia and the pale rockfinch). These groups are similar...
