Birds are a group of warm-blooded vertebrates constituting the class Aves (Latin: [ˈaveːs]), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich. There are over 11,000 living species and they are split into 44 orders. More than half are passerine or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. The study of birds is called ornithology.
Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs. Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians. Birds are descendants of the primitive avialans (whose members include Archaeopteryx) which first appeared during the Late Jurassic. According to some estimates, modern birds (Neornithes) evolved in the Late Cretaceous or between the Early and Late Cretaceous (100 Ma) and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non-ornithuran dinosaurs.
Many social species preserve knowledge across generations (culture). Birds are social, communicating with visual signals, calls, and songs, and participating in such behaviour as cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially (but not necessarily sexually) monogamous, usually for one breeding season at a time, sometimes for years, and rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction. They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.
Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertiliser. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry. (Full article...)
Bird extinction is the complete elimination of all species members under the taxonomic class, Aves. Out of all known bird species, (approximately 11,154), 159 (1.4%) have become extinct, with 226 (2%) being critically endangered. There is a general consensus among ornithologists that if anthropogenic activities continue as current trends suggest, one-third of all bird species, and an even greater proportion of bird populations, will be rendered extinct by the end of the 21st century.
For critically endangered species, scientists estimate they will face extinction in a few decades without proper conservation efforts; for some of these species, the current presence of extant populations is uncertain. (Full article...)
Charadriiformes (/kəˈrædri.ɪfɔːrmiːz/, from Charadrius, the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water and eat invertebrates or other small animals; however, some are pelagic (seabirds), others frequent deserts, and a few are found in dense forest. Members of this group can also collectively be referred to as shorebirds. (Full article...)
Anatomy: Anatomy • Skeleton • Flight • Eggs • Feathers • Plumage
Evolution and extinction: Evolution • Archaeopteryx • Hybridisation • Late Quaternary prehistoric birds • Fossils • Taxonomy • Extinction
Behaviour: Singing • Intelligence • Migration • Reproduction • Nesting • Incubation • Brood parasites
Bird orders: Struthioniformes • Tinamiformes • Anseriformes • Accipitriformes • Galliformes • Gaviiformes • Podicipediformes • Procellariiformes • Sphenisciformes • Pelecaniformes • Ciconiiformes • Phoenicopteriformes • Falconiformes • Gruiformes • Charadriiformes • Pteroclidiformes • Columbiformes • Psittaciformes • Cuculiformes • Strigiformes • Caprimulgiformes • Apodiformes • Coraciiformes • Piciformes • Trogoniformes • Coliiformes • Passeriformes
Bird lists: Families and orders • Lists by region
Birds and humans: Ringing • Ornithology • Bird collections • Birdwatching • Birdfeeding • Conservation • Aviculture
“ | You cannot fly like an eagle with the wings of a wren. | ” |
Free online resources:
There is also Birds of North America, Cornell University's massive project collecting information on every breeding bird in the ABA area. It is available for US$40 a year.
For more sources, including printed sources, see WikiProject Birds.
The Gibson Plumage Index (GPI), sometimes known as the Gibson Code, is a system for describing the plumage of great albatrosses. It is named after, and originally devised in the late 1950s by, John Douglas Gibson and other members of the New South Wales Albatross Study Group. Gibson was an Australian amateur ornithologist who carried out fieldwork on albatrosses along the coast of New South Wales for thirty years. The index assigns separate numerical values (from 1 to 6 with increasing proportion of white) to the degrees of colouration on four parts of the body - the back, head, inner wing and tail - of albatrosses to indicate variations in age and between different breeding populations. For instance, a bird with a completely brown back would receive a score of 1 for the back, while a bird with an all-white back would be scored as a 6. The index was later expanded by Pierre Jouventin and colleagues to cover the more complex patterning of the Amsterdam albatross, adding belly and tibial feather colouration. This system for categorising the wide and complex variation in appearance of great albatrosses has been instrumental in the discovery of several genetically isolated populations and consequent description of new taxa, and has made field identification easier. (Full article...)
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Class Aves, divided into superorders, orders, suborders (where indicated), and families. | ||||
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