Passeridae – Old World Sparrows

Passeridae (Snowfinches, Sparrows & Petronias) are a family of small passerines, the old-world sparrows and allies. 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.

The 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 to each other, and are each fairly homogeneous, especially Passer.

Chestnut Sparrow Passer eminibey – ©Dubi Shapiro

Some classifications used to include the sparrow-weavers (Plocepasser), the related estrildid finches of the Old-World tropics and Australasia and several other African genera (otherwise classified among the weavers (Ploceidae), which are morphologically similar to Passer. A more recent study including DNA sequencing has narrowed those in this family. However, a study of molecular and skeletal evidence of the Cinnamon Ibon of the Philippines, previously considered to be a white-eye, showed it to be a sister taxon to the sparrows. It is therefore now classified as its own subfamily within Passeridae.

Cinnamon Ibon Hypocryptadius cinnamomeus – Dubi Shapiro

Many species nest on buildings, and the House Sparrow and Eurasian Tree Sparrow in particular inhabit cities in large numbers, so sparrows are among 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 edible in small quantities.

Generally, sparrows are small, plump, brown-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 and 13.4 grams, to the Parrot-billed Sparrow Passer gongonensis, at 18 centimetres and 42 grams. 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.

Eurasian Tree Sparrow Passer montanus – ©Nick Ludovic Green Bird-Photo-Tours ASIA

Sparrows are generally social birds, with many species breeding in loose colonies and most species occurring in flocks during the non-breeding season. The house sparrow typically lays three to six eggs, but has been known to lay as few as one and as many as eight greenish-white eggs. The incubation period is typically ten to fourteen days.

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. The assemblages can be quite large with up to 10,000 House Sparrows counted in one roost in Egypt.

Rufous-necked Snowfinch Pyrgilauda ruficollis

Tibetan Snowfinch Montifringilla adamsi

The two photos above courtesy of ©Dubi Shapiro

The sparrows are some of the few passerine birds that engage in dust bathing. Sparrows will first scratch a hole in the ground with their feet, then lie in it and fling dirt or sand over their bodies with flicks of their wings. They will also bathe in water, or in dry or melting snow. Water bathing is similar to dust bathing, with the sparrow standing in shallow water and flicking water over its back with its wings, also ducking its head under the water. Both activities are social, with up to a hundred birds participating at once, and is followed by preening and sometimes group singing.