Passeriformes (Perching Birds)

(vertebrate zoology) A large order of perching birds comprising two major divisions: Suboscines and Oscines.

Family: Broadbills
Family: False Sunbirds and Asities
Family: Pittas
Family: New Zealand Wrens
Family: Ovenbirds
Family: Woodcreepers
Family: Ant Thrushes
Family: Tapaculos
Family: Tyrant Flycatchers
Family: Sharpbills
Family: Manakins
Family: Cotingas
Family: Plantcutters
Family: Lyrebirds
Family: Scrub-Birds
Family: Larks
Family: Swallows
Family: Pipits and Wagtails
Family: Cuckoo-Shrikes
Family: Bulbuls
Family: Fairy Bluebirds and Leafbirds
Family: Shrikes
Family: Vanga Shrikes
Family: Waxwings and Silky Flycatchers
Family: Palmchats
Family: Hedge Sparrows
Family: Thrashers and Mockingbirds
Family: Dippers
Family: Thrushes and Chats
Family: Babblers
Family: Wrens
Family: Old World WarblersFamily: Old World Flycatchers
Family: Australian Fairy-Wrens
Family: Australian Warblers
Family: Australian Chats
Family: Logrunners and Chowchillas
Family: Quail Thrushes and Whipbirds
Family: Fantails
Family: Monarch Flycatchers
Family: Australian Robins
Family: Whistlers
Family: Pseudo Babblers
Family: Australian Creepers
Family: Long-Tailed Titmice
Family: Penduline Titmice
Family: Titmice and Chickadees
Family: Nuthatches and Wall Creepers
Family: Treecreepers
Family: Philippine Creepers
Family: Flowerpeckers
Family: Pardalotes
Family: Sunbirds
Family: White-Eyes
Family: Australian Honeyeaters
Family: Vireos and Peppershrikes
Family: New World Finches
Family: New World Warblers
Family: New World Blackbirds and Orioles
Family: Finches
Family: Hawaiian Honeycreepers
Family: Waxbills and Grassfinches
Family: Weavers
Family: Sparrows
Family: Starlings and Mynas
Family: Old World Orioles and Figbirds
Family: Drongos
Family: New Zealand Wattle Birds
Family: Mudnest Builders
Family: Woodswallows
Family: Magpie-Shrikes
Family: Bowerbirds
Family: Birds of Paradise
Family: Crows and Jays

(Perching birds)

Class: Aves

Order: Passeriformes

Number of families: Approximately 74

Number of genera, species: Approximately 1,161 genera and 5,700 species

Evolution and systematics

With more than 5,700 species—approximately 59% of the total number of bird species—passerines make up the single largest order of birds in the world. Indeed, many researchers roughly divide all birds into two major categories: passerines, and everything else.

Other than the large size of the order, however, there is very little that can be generally said about passerines. Members of this species-rich order are usually small, morphologically uniform, terrestrial birds that eat mainly seeds, fruit, nectar, and/or insects. Australian lyrebirds (Menura) and ravens (Corvus corax; weight approximately 60 oz [1,700 g]) are the largest members of the order, and bushtits (Psaltriparus) and pygmy tits (Psaltria exilis) are the smallest.

Nearly all taxonomists agree that Passeriformes are monophyletic, meaning they share a common ancestor, but beyond that there is little agreement about the evolutionary history and genetic relationships of this order. Robert J. Raikow defines the group with five derived characters: a wing tendon architecture that is unique; except in one genus (Conopophaga), a distinctive palate called "aegithognathous"; unique, bundled sperm structure; and a highly specialized foot and leg that facilitate perching, with a large hallux (rear toe) that is specially arranged, deep plantar tendons, and simplified foot muscles. Researchers agree that these characters are unique to the order, but some also cite other, traditional morphological features as defining the group. These features include, among others, the arrangement of the toes (anisodactyl, or three toes forward, one toe pointing rearward), an incumbent (non-elevated), independently acting hallux, and distinctive syringeal architecture. Raikow, however, claims that all these features are more general within birds as a whole, and therefore not useful for establishing passerine monophyly.

DNA analysis may prove to be a critical tool for defining the phylogeny, or genealogical relationships, among birds, especially in the case of subdivision of the order. Except for the architecture of the syrinx and feet, passerines are remarkably similar in morphology. Differences in the syrinx have allowed for two generally recognized suborders, Tyranni (suboscines) and Passeri (oscines). However, beyond these large suborders, classification has been extremely problematic. Convergent and parallel evolution has produced structural features and behaviors that are remarkably similar in birds that are, in fact, not closely related. However, divergent features have evolved in some species that are closely related. As a consequence, many species and genera have been traditionally, but possibly incorrectly, grouped together in families on the basis of similar morphologic features. Charles Sibley, Jon Ahlquist, and Burt Monroe have proposed a reorganization of passerines, particularly oscines, using DNA hybridization techniques. However, though these techniques promise to provide additional insight into these relationships, it may still take some time before passerine systematics are fully understood.

Resources

Brooke, M. "Order: Passeriformes." In The Cambridge Encyclopedia of Ornithology, edited by M. Brooke, and T. Birkhead. Cambridge: Cambridge University Press, 1991.

Catchpole, C. K., and P. J. B. Slater. Bird Song: Biological Themes and Variations. Cambridge, Cambridge University Press, 1995.

Ehrlich, P. R., D. S. Dobkin, and D. Wheye. The Birder's Handbook. Cambridge: Cambridge University Press, 1995.

Feduccia, A. The Origin and Evolution of Birds. 2nd ed. New Haven: Yale University Press, 1999.

Gill, F. B. Ornithology. 2nd ed. New York: W. H. Freeman and Company, 1995.

Short, L. L. The Lives of Birds. New York: Henry Holt and Company, 1993.

Sibley, C. G., and J. E. Ahlquist. Phylogeny and Classification of Birds. New Haven: Yale University Press, 1990.

Sibley, C. G., and B. L. Monroe Jr. Distribution and Taxonomy of Birds of the World. New Haven: Yale University Press, 1990.

Skutch, A. Antbirds and Ovenbirds. Austin: University of Texas Press, 1996.

Bledsoe, A. H. "Nuclear DNA Evolution and Phylogeny of the New World Nine-primaried Oscines." Auk 105 (1988): 559–571.

Collias, N. "On the Origin and Evolution of Nest Building by Passerine Birds." Condor 99 (1997): 253–270.

Conway, C. J., and T. E. Martin. "Evolution of Passerine Incubation Behavior: Influence of Food, Temperature, and Nest Predation." Evolution 54, no. 2 (2000): 670–685.

Cracraft, J. "Avian Evolution, Gondwana Biogeography and the Cretaceous-Tertiary Mass Extinction Event." Proc. Royal Society London, Series B 268 (2001): 459–469.

Olson, S. L., R. J. Raikow, and A. H. Bledsoe. "Why So Many Kinds of Passerine Birds?" BioScience 51, no. 4 (2001): 268–70.

Raikow, R. J., and A. H. Bledsoe. "Phylogeny and Evolution of the Passerine Birds." BioScience 50, no. 6 (2000): 487–499.

Sheldon, F. H., and D. Winkler. "Nest Architecture and Avian Systematics." Auk 116, no. 4 (1999): 875–877.

[Article by: Susan L. Tomlinson, PhD]

The largest and most diverse order of birds, which is found worldwide, including most oceanic islands but excluding Antarctica, in all terrestrial habitats. The most closely related species may be other land birds such as the Coraciiformes and the Piciformes. The Passeriformes is divided into the suborders: Eurylaimi, Furnarii, Tyranni, and Oscines. The affinities of most families within those suborders is still much disputed. See also Coraciiformes; Piciformes.

The perching birds are small to medium-sized birds, ravens (Corvus corax) being the largest. The wings are short to medium in length and vary from rounded to pointed. A few species, including lyrebirds, scrubbirds, and New Zealand wrens, are almost flightless. The tail varies from nearly absent to long. The bill is widely variable in shape. Passeriforms have legs of short to medium length that are usually strong. The four toes show the usual avian arrangement, three in front and a well-developed hallux behind. Most forms can walk or climb well, or both. Plumage varies widely, from all black to mostly white and from bright colors and bold patterns to cryptic coloration.

Feeding habits and food choices show wide variation. Most species eat insects or small animals. Song is important to most perching birds for species recognition and courtship. The pair bond is usually strong, with both sexes incubating and caring for the young, which remain in the nest until they are able to fly. Many arctic and cold temperature passerine species migrate to warmer areas for the cold months. Some of the migratory flights measure several thousand miles. See also Aves.