Cannabaceae

The Birds Portal

Birds are a group of warm-blooded vertebrates constituting the class Aves (/ˈvz/), 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, more than half of which 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 recent estimates, modern birds (Neornithes) evolved in the Late Cretaceous and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non-avian dinosaurs.

Many social species pass on knowledge across generations, which is considered a form of culture. Birds are social, communicating with visual signals, calls, and songs, and participating in such behaviours 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...)

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The 'Gazebo' hide at the West Midland Bird Club's Belvide Reservoir reserve.

A bird hide (blind or bird blind in North America) is a shelter, often camouflaged, that is used to observe wildlife, especially birds, at close quarters. Although hides or hunting blinds were once built chiefly as hunting aids, they are now commonly found in parks and wetlands for the use of birdwatchers, ornithologists and other observers who do not want to disturb wildlife as it is being observed.

A typical bird hide resembles a garden shed, with small openings, shutters, or windows built into at least one side to enable observation. However, because birds do not recognize humans as predatory threats unless the human is standing in the open, a bird blind can be little more than a large shed open on one side in which birders stand, and motor vehicles are effective blinds even with the windows open. (Full article...)
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Selected taxon

Bustards, including floricans and korhaans, are large, terrestrial birds living mainly in dry grassland areas and on the steppes of the Old World. They range in length from 40 to 150 cm (16 to 59 in). They make up the family Otididae (/ˈtɪdɪd/, formerly known as Otidae).

Bustards are omnivorous and opportunistic, eating leaves, buds, seeds, fruit, small vertebrates, and invertebrates. There are 26 species currently recognised. (Full article...)
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Quotes

--Edward Jeffrey, a British clergyman [1], The New York Times, June 21, 1964

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Resources

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.

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Selected bird anatomy topic

This stylised bird skeleton highlights the keel bone

A keel or carina (pl.: carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight. Not all birds have keels; in particular, some flightless birds lack a keel structure. Some flightless birds have a keel, such as the penguin; but in the penguin's case, its wings are too small for its body, so flight would require flapping its wings too fast to be practical.

Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from carina, "keel"), having a pronounced keel; and ratites (from ratis, "raft" – referring to the flatness of the sternum), having a subtle keel structure or lacking one entirely. However, this classification has become disused as evolutionary studies have shown that many flightless birds have evolved from flighted birds. (Full article...)
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Selected species

Turkey vulture
The turkey vulture, Cathartes aura, also known in North America as the turkey buzzard, is a bird found throughout most of the Americas. One of three species in the genus Cathartes, in the family Cathartidae, it is the most common of the New World vultures, ranging from southern Canada to the southernmost tip of South America. It inhabits a variety of open and semi-open areas. It has dark brown to black plumage, a featherless, purplish-red head and neck, and a short, hooked, ivory-colored beak. It is a scavenger and feeds almost exclusively on carrion. It finds its meals using its sense of smell, flying low enough to detect the gases produced by the beginnings of the process of decay in dead animals. In flight, it uses thermals to move through the air, flapping its wings only infrequently. Lacking a syrinx—the vocal organ of birds—its only vocalizations are grunts or low hisses. It nests in caves, hollow trees, or thickets, generally raising two chicks each year, which it feeds by regurgitation.


Did you know

  • ...that sexual size dimorphism in the brown songlark is among the most pronounced in any bird, with males as much as 2.3 times heavier than females?
  • ...that rufous whistler birds, unlike all other whistler birds, never forage on the ground but high up in trees or other high places?
  • ...that the bill of the magpie duck (pictured) becomes green as the bird gets older, and its black crown may go completely white?

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Taxonomy of Aves

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  • Wikiquote
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  • Wikispecies
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  • Wikiversity
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  • Wikivoyage
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  • Wiktionary
    Dictionary and thesaurus

Sources

  1. ^ Applewhite, A.; Evans, T.; Frothingham, A. (2003). And I Quote, Revised Edition: The Definitive Collection of Quotes, Sayings, and Jokes for the Contemporary Speechmaker. Thomas Dunne Books. St. Martin's Press. p. 216. ISBN 978-0-312-30744-8. Retrieved February 7, 2020.
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