A passerine is any bird of the order Passeriformes which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their toes, which facilitates perching.
A songbird is a bird belonging to the suborder Passeri of the perching birds (Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin oscen, "songbird". The Passeriformes contains 5,000 or so species found all over the world, in which the vocal organ typically is developed in such a way as to produce a diverse and elaborate bird song.
The Tyranni (suboscines) are a suborder of passerine birds that includes more than 1,000 species, the large majority of which are South American. It is named after the type genus Tyrannus. These have a different anatomy of the syrinx musculature than the oscines, hence the common name of suboscines.
Passerida is, under the Sibley-Ahlquist taxonomy, one of two parvorders contained within the suborder Passeri. While more recent research suggests that its sister parvorder, Corvida, is not a monophyletic grouping, the Passerida as a distinct clade are widely accepted.
Birds of South Asia: The Ripley Guide by Pamela C. Rasmussen and John C. Anderton is a two-volume ornithological handbook, covering the birds of South Asia, published in 2005 by the Smithsonian Institution and Lynx Edicions. The geographical scope of the book covers India, Bangladesh, Pakistan, Sri Lanka, Nepal, Bhutan, Maldives, the Chagos Archipelago and Afghanistan. In total, 1508 species are covered. Two notable aspects of Birds of South Asia are its distribution evidence-base — the book's authors based their distributional information almost completely on museum specimens — and its taxonomic approach, involving a large number of species-level splits.
Eupasserines are passerines in the clade Eupasseres. The clade contains all passerines except the New Zealand wrens (Acanthisitti), to which they are sister.
