Birds are a group of warm-blooded vertebrates constituting the class Aves, 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 common ostrich. There are about ten thousand 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.
Poultry are domesticated birds kept by humans for the purpose of harvesting useful animal products such as meat, eggs or feathers. The practice of raising poultry is known as poultry farming. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes. The term also includes waterfowls of the family Anatidae and other flying birds that are kept and killed for their meat such as the young pigeons, but does not include wild birds hunted for food known as game or quarry.
Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier example of a complex evolutionary novelty. They are among the characteristics that distinguish the extant birds from other living groups.
The greater flamingo is the most widespread and largest species of the flamingo family. Common in the Old World, they are found in Northern (coastal) and Sub-Saharan Africa, the Indian Subcontinent, the Middle East, the Levant, the Persian Gulf, the Gulf of Aden, the Red Sea, and the Mediterranean countries of Southern Europe.
The rock dove, rock pigeon, or common pigeon is a member of the bird family Columbidae. In common usage, it is often simply referred to as the "pigeon".
James's flamingo, also known as the puna flamingo, is a species of flamingo that lives at high altitudes in the Andean plateaus of Peru, Chile, Bolivia, and northwest Argentina.
Sebacic acid is a naturally occurring dicarboxylic acid with the chemical formula HO2C(CH2)8CO2H. It is a white flake or powdered solid. Sebaceus is Latin for tallow candle, sebum is Latin for tallow, and refers to its use in the manufacture of candles. Sebacic acid is a derivative of castor oil.
Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main component of the uropygium, a structure colloquially known as the bishop's nose, parson's nose, pope's nose, or sultan's nose. This is the fleshy protuberance visible at the posterior end of a bird that has been dressed for cooking. It has a swollen appearance because it also contains the uropygial gland that produces preen oil.
The domestic pigeon is a pigeon subspecies that was derived from the rock dove or rock pigeon. The rock pigeon is the world's oldest domesticated bird. Mesopotamian cuneiform tablets mention the domestication of pigeons more than 5,000 years ago, as do Egyptian hieroglyphics. Research suggests that domestication of pigeons occurred as early as 10,000 years ago.
The American flamingo is a large species of flamingo native to the West Indies, northern South America and the Yucatan Peninsula. It is closely related to the greater flamingo and Chilean flamingo, and was formerly considered conspecific with the greater flamingo, but that treatment is now widely viewed as incorrect due to a lack of evidence. It is also known as the Caribbean flamingo, although it is also present in the Galápagos Islands. It is the only flamingo that naturally inhabits North America.
Ducula is a genus of the pigeon family Columbidae, collectively known as imperial pigeons. They are large to very large pigeons with a heavy build and medium to long tails. They are arboreal, feed mainly on fruit and are closely related to the other genus of fruit-eating doves, Ptilinopus. Both genera display brightly coloured plumage, predominantly green, often with contrasting under-parts of purple, orange or red. Some Ducula have prominently swollen ceres. They have large gapes and swallow seeds whole, playing an important role in seed dispersal.
The proventriculus is part of the digestive system of birds. An analogous organ exists in invertebrates and insects.
The following outline is provided as an overview of and topical guide to birds:
Sexual selection in birds concerns how birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are energetically costly attributes that signal competitive breeding situations. Many types of avian sexual selection have been identified; intersexual selection, also known as female choice; and intrasexual competition, where individuals of the more abundant sex compete with each other for the privilege to mate. Sexually selected traits often evolve to become more pronounced in competitive breeding situations until the trait begins to limit the individual's fitness. Conflicts between an individual fitness and signaling adaptations ensure that sexually selected ornaments such as plumage coloration and courtship behavior are “honest” traits. Signals must be costly to ensure that only good-quality individuals can present these exaggerated sexual ornaments and behaviors.
The Eurasian hoopoe is the most widespread species of the genus Upupa. It is a distinctive cinnamon coloured bird with black and white wings, a tall erectile crest, a broad white band across a black tail, and a long narrow downcurved bill. Its call is a soft "oop-oop-oop".
Corynebacterium uropygiale is a bacterium described in 2016 following thorough investigations using a polyphasic approach including MALDI-TOF mass spectrometry, phylogeny of 16S rRNA and rpoB genes and DNA fingerprinting. To date, it has been regarded as endemic to preen gland secretions of healthy turkeys . It is a member of the genus Corynebacterium, which belongs to the phylum Actinomycetota. Although a large number of bacteria including corynebacteria have been reported as part of the normal microbiome of birds, C. uropygiale is the only member of the genus that has been recovered in preen gland secretions of birds. It is one of three bacterial species to have been found to colonize preen gland secretions of birds.
The following is a glossary of common English language terms used in the description of birds—warm-blooded vertebrates of the class Aves and the only living dinosaurs, characterized by feathers, the ability to fly in all but the approximately 60 extant species of flightless birds, toothless, beakedjaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart and a strong yet lightweight skeleton.
Preening is a maintenance behaviour found in birds that involves the use of the beak to position feathers, interlock feather barbules that have become separated, clean plumage, and keep ectoparasites in check. Feathers contribute significantly to a bird's insulation, waterproofing and aerodynamic flight, and so are vital to its survival. Because of this, birds spend considerable time each day maintaining their feathers, primarily through preening. Several actions make up preening behaviour. Birds fluff up and shake their feathers, which helps to "rezip" feather barbules that have become unhooked. Using their beaks, they gather preen oil from a gland at the base of their tail and distribute this oil through their feathers. They draw each contour feather through their bill, nibbling it from base to tip.
The rock dove, Columbia livia, has a number of special adaptations for regulating water uptake and loss.
