Passerine

Passerine, common name for any of the perching birds belonging to the largest avian order, which includes more than 5,700 highly diverse species and well over half of all living birds. Passerines are distinguished by four-toed feet, with three toes pointing forward and one large toe pointing backwards. Most are songbirds with highly developed syrinxes, or vocal organs. Finches, wrens, swallows, nightingales, crows, warblers, and flycatchers are only a few of the many birds in the passerine order.

In quite recent evolutionary times, passerines underwent an explosive adaptive radiation, utilizing insect- and seed-rich niches of forests and fields. Passerines are highly diverse in body size, ranging from kinglets at about 5 g (0.18 oz) to ravens at about 1,400 g (3 lb). Some, such as crossbills, dippers, and swallows have bill, wing, and leg shapes reflecting highly specialized methods of foraging. Others, such as the crows and jays, are generalists.

The largest suborder of the passerines is the songbirds, or oscines, comprising more than 4,500 species. It includes the thrushes, which have complexly muscled syrinxes (vocal organs) that can produce and imitate a great range of notes and rhythms. Passerines of the three much smaller suborders have less complex syrinxes and are often called suboscines.

Scientific classification: Passerines make up the order Passeriformes. Songbirds make up the suborder Passeres.