Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized 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 cm (2 in) bee hummingbird to the 2.75 m (9 ft) 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 evolved from 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.
A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or songbirds, passerines are distinguished from other orders of birds by the arrangement of their toes, which facilitates perching.
Birds of prey, also known as raptors, include species of bird that primarily hunt and feed on vertebrates that are large relative to the hunter. Additionally, they have keen eyesight for detecting food at a distance or during flight, strong feet equipped with talons for grasping or killing prey, and powerful, curved beaks for tearing flesh. The term raptor is derived from the Latin word rapio, meaning to seize or take by force. In addition to hunting live prey, many birds, such as fish eagles, vultures and condors, eat carrion.
Hawks are a group of medium-sized diurnal birds of prey of the family Accipitridae. Hawks are widely distributed and vary greatly in size.
Columbidae is a bird family consisting of pigeons and doves. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks, and short slender bills that in some species feature fleshy ceres. They primarily feed on seeds, fruits, and plants. The family occurs worldwide, but the greatest variety is in the Indomalayan and Australasian realms.
The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in Papua New Guinea and eastern Australia. The family has 42 species in 15 genera. The members of this family are perhaps best known for the plumage of the males of the sexually dimorphic species, in particular the highly elongated and elaborate feathers extending from the beak, wings, tail or head. For the most part they are confined to dense rainforest habitat. The diet of all species is dominated by fruit and to a lesser extent arthropods. The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek-type polygamy.
The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists determined the subfamily Saxicolinae, which includes the chats and European robins, were Old World flycatchers. Thrushes are small to medium-sized ground living birds that feed on insects, other invertebrates and fruit. Some unrelated species around the world have been named after thrushes due to their similarity to birds in this family.
The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. They are not closely related to Old World warblers or Australian warblers. Most are arboreal, but some, like the ovenbird and the two waterthrushes, are primarily terrestrial. Most members of this family are insectivores.
Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed recently and the number of genera is disputed. The great cormorant and the common shag are the only two species of the family commonly encountered on the British Isles and "cormorant" and "shag" appellations have been later assigned to different species in the family somewhat haphazardly.
The Phasianidae are a family of heavy, ground-living birds, which includes pheasants, partridges, junglefowl, chickens, turkeys, Old World quail, and peafowl. The family includes many of the most popular gamebirds. The family is a large one, and is occasionally broken up into two subfamilies, the Phasianinae and the Perdicinae. Sometimes, additional families and birds are treated as part of this family. For example, the American Ornithologists' Union includes the Tetraonidae (grouse), Numididae (guineafowl), and Meleagrididae (turkeys) as subfamilies in Phasianidae.
The tanagers comprise the bird family Thraupidae, in the order Passeriformes. The family has an American distribution. The Thraupidae are the second-largest family of birds and represent about 4% of all avian species and 12% of the Neotropical birds.
Passerida is, under the Sibley-Ahlquist taxonomy, one of two parvorders contained within the suborder Passeri. While more recent research suggests that its sister parvorder, Corvida, is not a monophyletic grouping, the Passerida as a distinct clade are widely accepted.
The green-tailed warbler, also known as the green-tailed ground warbler, is a species of songbird endemic to the island of Hispaniola and adjacent islets. It has occurred as a vagrant on the Turks and Caicos Islands.
The black-crowned tanager or black-crowned palm-tanager is a species of bird of the family Phaenicophilidae, which was formerly placed in the family Thraupidae. It is found on Hispaniola.
Phaenicophilus is a genus of birds that was formerly placed in the family Thraupidae, but is now placed in the Hispaniolan tanager family Phaenicophilidae. Its members are sometimes known as palm-tanagers.
The grey-crowned tanager or grey-crowned palm-tanager is a species of bird in the family Phaenicophilidae. It was formerly placed in the family Thraupidae. It is found in Haiti.
The white-winged warbler, also called Hispaniolan highland-tanager, is a species of bird classified in the family Phaenicophilidae. It is the only member of the genus Xenoligea, and is found solely on Hispaniola.
Toucans are members of the Neotropical near passerine bird family Ramphastidae. The Ramphastidae are most closely related to the American barbets. They are brightly marked and have large, often-colorful bills. The family includes five genera and over forty different species.
