How Can We Help?
< Back

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...)

Featured articles

Selected general bird topic

The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. Birds are categorized as a biological class, Aves. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird. Modern phylogenies place birds in the dinosaur clade Theropoda. According to the current consensus, Aves and a sister group, the order Crocodilia, together are the sole living members of an unranked reptile clade, the Archosauria. Four distinct lineages of bird survived the Cretaceous–Paleogene extinction event 66 million years ago, giving rise to ostriches and relatives (Palaeognathae), waterfowl (Anseriformes), ground-living fowl (Galliformes), and "modern birds" (Neoaves). Phylogenetically, Aves is usually defined as all descendants of the most recent common ancestor of a specific modern bird species (such as the house sparrow, Passer domesticus), and either Archaeopteryx, or some prehistoric species closer to Neornithes (to avoid the problems caused by the unclear relationships of Archaeopteryx to other theropods). If the latter classification is used then the larger group is termed Avialae. Currently, the relationship between dinosaurs, Archaeopteryx, and modern birds is still under debate. (Full article...)
List of selected general topics

Selected taxon

California gnatcatcher (Polioptila californica)
The gnatcatchers are a family of small passerine birds called Polioptilidae. The 21 species occur in North and South America (except for the far south and the high Andean regions). Most species of this mainly tropical and subtropical group are resident, but the blue-grey gnatcatcher of the United States and southern Canada migrates south in winter. They are close relatives of the wrens. (Full article...)
List of selected taxon articles

Topics

Quotes

...All quotes
...Show another quote

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.

WikiProjects

Selected images

Selected bird anatomy topic

This stylised bird skeleton highlights the uncinate processes

The uncinate processes of the ribs are extensions of bone that project caudally from the vertical segment of each rib. (Uncinate means hooked from Latin uncinatus, from uncinus, barb, from uncus, hook.) They are found in birds (except for screamers), reptiles, and the early amphibian Ichthyostega.

These processes can serve to attach scapula muscles, and help to strengthen the rib cage overlapping with the rib behind them. They are also shown to have a role in respiration by increasing the effectiveness of muscles involved in inspiration including the appendicocostal muscles. The processes are short in walking birds and long in diving species and are of intermediate length in non-specialist birds. The screamers (Anhimidae) are unique in lacking this process. The process has also been noted in some enantiornitheans. Although among living vertebrates, bony uncinate processes are unique to birds, cartilaginous uncinate processes are present in crocodiles. The uncinate process has also been reported in Sphenodon and fossil vertebrates including Caudipteryx, oviraptorids, dromaeosaurids, Confuciusornis, Chaoyangia, and Longipteryx; however it apparently does not occur in Archaeopteryx, though Codd et al. (2007) reported uncinate processes in Archaeopteryx. (Full article...)
List of selected anatomy articles

Selected species

Elfin-woods warbler
The elfin-woods warbler (Dendroica angelae, Spanish: reinita de bosque enano), is a bird endemic to the Caribbean island of Puerto Rico where it is a local and uncommon species. It was discovered in 1968 and described in 1972. The species name, angelae, is a tribute to Angela Kepler, one of its discoverers. An insectivore, it feeds by gleaning small insects off leaves. Due to its small populations and restricted habitats, conservation efforts were begun in 1982 to protect this species. The species is not in immediate danger as the majority of its habitat is protected forest, but introduced species, such as rats and mongooses, habitat reduction, and natural disasters represent potential threats to the population.


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?

Categories

Related portals

Things you can do

Create requested articles (WikiProject Birds – Article requests):

Do these tasks:


Here are some tasks awaiting attention:

More outstanding tasks at the project's cleanup listing, Category:Birds articles needing attention, and Wikipedia:WikiProject Birds/Todo.

Taxonomy of Aves

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

  • Commons
    Free media repository
  • Wikibooks
    Free textbooks and manuals
  • Wikidata
    Free knowledge base
  • Wikinews
    Free-content news
  • Wikiquote
    Collection of quotations
  • Wikisource
    Free-content library
  • Wikispecies
    Directory of species
  • Wikiversity
    Free learning tools
  • Wikivoyage
    Free travel guide
  • Wiktionary
    Dictionary and thesaurus

Sources

  1. ^ Gaither, C.C.; Cavazos-Gaither, A.E. (2012). Gaither's Dictionary of Scientific Quotations. Springer New York. p. 1660. ISBN 978-1-4614-1114-7. Retrieved February 7, 2020.
Discover Wikipedia using portals

Purge server cache

Categories
Table of Contents