Tuesday, April 22, 2008

True Parrots


The true parrots are about 330 species of bird belonging to the Psittacidae family, one of the two "traditional" families in the biological order Psittaciformes (parrots). The other family is the Cacatuidae (cockatoos) which are also parrots, but not classified as true parrots. True parrots are more widespread than cockatoos, with species in the Americas, Africa, Asia, Australia and eastwards across the Pacific Ocean as far as Polynesia.
The true parrot family is often considered to contain two subfamilies, the Psittacinae (typical parrots and allies) and the Loriinae (Lories and lorikeets). However, there are other systems of classification and these two groups are sometimes ascribed full family status, being called Psittacidae and Loriidae. This does not seem to be warranted however, though treating cockatoos and certain lineages of true parrots at equal taxonomic rank (but not as families) may well be so; see below for why.

Hummingbirds


Hummingbirds are birds of the family Trochilidae, and are native only to the Americas. They are known for their ability to hover in mid-air by rapidly flapping their wings 15–80 times per second (depending on the species). Capable of sustained hovering, the hummingbird also has the ability to fly backwards, being the only group of birds able to do so.Hummingbirds may also fly vertically or horizontally, and are capable of maintaining a position while drinking nectar or eating tiny arthropods from flower blossoms. Their English name derives from the characteristic hum made by their wings

Owls


Owls are an order of birds of prey. Most are solitary, and nocturnal, with some exceptions (e.g. the Burrowing Owl). They are classified in the order Strigiformes, in which there are over 200 extant species. Owls mostly hunt small mammals, insects, and other birds, though a few species specialize in hunting fish. They are found in all regions of the Earth except Antarctica, most of Greenland, and some remote islands. Though owls are typically solitary, the literary collective noun for a group of owls is a parliament.

Old World vultures


Old World vultures belong to the family Accipitridae, which also includes eagles, buzzards, kites, and hawks.
Old World vultures are not closely related to the superficially similar New World vultures and condors, and do not share that group's good sense of smell. The similarities between the two groups of vultures are due to convergent evolution rather than a close relationship. They were widespread in both the Old World and North America, during the Neogene. Old World vultures are probably a polyphyletic group within Accipitridae, with Palm-nut Vulture, Egyptian Vulture and Lammergeier separate from the others.Both Old World and New World vultures are scavenging birds, feeding mostly from carcasses of dead animals. Old World vultures find carcasses exclusively by sight. A particular characteristic of many vultures is a bald head, devoid of feathers. If vultures had head feathers, they would become spattered with blood and other fluids when the vultures ate flesh from carcasses, and thus would be difficult to keep clean

Kite(Bird)


Kites are raptors with long wings and weak legs which spend a great deal of time soaring. In general they feed on carrion but may also take live prey.
They are birds of prey which along with hawks, eagles, Old World vultures and many others are in the family Accipitridae.
Together with less closely related groups such as New World vultures and Osprey, they make up the diurnal bird of prey order Falconiformes.

Harrier(Bird)


A Harrier is any of several species of diurnal birds of prey which fly low over meadows and marshes and hunt or harry small animals or birds (hence their common name). Most are in the genus Circus, the scientific name also arising from the circling movements male and female make when mating

Eagle


Eagles are large birds of prey which mainly inhabit Eurasia and Africa. Outside this area, just two species (the Bald and Golden Eagles) are found in North America north of Mexico, with a few more species in Central and South America, and three in Australia.
They are members of the bird order Falconiformes (or Accipitriformes, according to alternative classification schemes), family Accipitridae, and belong to several genera which are not necessarily closely related to each other in any sort of way.
Eagles are differentiated from other birds of prey mainly by their larger size, more powerful build, and heavier head and bill. Even the smallest eagles, like the Booted Eagle (which is comparable in size to a Common Buzzard or Red-tailed Hawk), have relatively longer and more evenly broad wings, and more direct, faster flight. Most eagles are larger than any other raptors apart from the vultures.

Hawk


The term hawk can be used in several ways:
In strict usage in Europe and Asia, to mean any of the species in the subfamily Accipitrinae in the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter includes goshawks, sparrowhawks , the Sharp-shinned Hawk and others. These are mainly woodland birds with long tails and high visual acuity, hunting by sudden dashes from a concealed perch.
More generally (especially in North America) to mean small to medium-sized members of (often) the Falconidae, Pandionidae (the Osprey) and the Accipitridae - the family which includes the "true hawks" (Accipiters) as well as eagles, kites, harriers and buzzards.
Loosely, to mean almost any bird of prey outside of the order Strigiformes (owls).

Palm Cockatoo


The Palm Cockatoo (Probosciger aterrimus), also known as the Goliath Aratoo, is a large black parrot of the cockatoo family and this species is unique in its kind. It is the only member in subfamily Microglossinae and monotypic genus Probosciger. Its unique position within the cockatoo family has been confirmed by molecular studies (Brown & Toft, 1999, Astuti, 2004?).
The Palm Cockatoo is distributed in rainforests and woodlands of New Guinea and northern Queensland, Australia. It measures around 55-60 cm in length and weighs between 500-1,000 g. It is a distinctive bird with a large crest and has one of the largest bills of any parrots (only the Hyacinth Macaw's is larger). The bill is unusual as the lower and upper mandibles do not meet for much of its length, allowing the tongue to hold a nut against the top mandible while the lower mandible works to open it. The Palm Cockatoo also has a distinctive red gape that changes colour when the bird is alarmed or excited.
The Palm Cockatoo makes four different kinds of vocalisations. It has a unique display where the bird drums a large branch against a dead bough or tree, creating a loud noise that can be heard up to 100 m away.
This species is in high demand for the pet trade due to its unusual appearance, and does not breed well in captivity, requiring the removal of wild birds. It is still relatively common in Cape York, but is threatened there by habitat loss. The Palm Cockatoo is currently evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix I of CITES.

Swift


The swifts are birds superficially similar to swallows but are actually not closely related to those passerine species at all; swifts are in the separate order Apodiformes, which they formerly shared with the hummingbirds. The treeswifts are closely related to the true swifts, but form a separate family, the Hemiprocnidae.
The resemblances between the swifts and swallows are due to convergent evolution reflecting similar life styles based on catching insects in flight.
The family scientific name comes from the Ancient Greek απους, apous, meaning "without feet", since swifts have very short legs and never settle voluntarily on the ground, perching instead on vertical surfaces. The tradition of depicting swifts without feet continued into the Middle Ages, as seen in the heraldic martlet.
Swifts are the most aerial of birds and some, like the Common Swift, even sleep and mate on the wing. Larger species, such as White-throated Needletail, are amongst the fastest flyers in the animal kingdom. One group, the Swiftlets or Cave Swiftlets have developed a form of echolocation for navigating through dark cave systems where they roost. One species, Aerodramus papuensis has recently been discovered to use this navigation at night outside its cave roost also.
Swifts have a worldwide distribution in tropical and temperate areas, but like swallows and martins, the swifts of temperate regions are strongly migratory and winter in the tropics.

Seabirds


Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene.
In general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely.
Seabirds and humans have a long history together: they have provided food to hunters, guided fishermen to fishing stocks and led sailors to land. Many species are currently threatened by human activities, and conservation efforts are under way.

Saturday, April 19, 2008

Gulls


Gulls (often informally Seagulls) are birds in the family Laridae. They are most closely related to the terns (family Sternidae) and only distantly related to auks, and skimmers, and more distantly to the waders. Most gulls belong to the large genus Larus.
They are typically medium to large birds, usually grey or white, often with black markings on the head or wings. They have stout, longish bills, and webbed feet. Gull species range in size from the Little Gull, at 120 g (4.2 oz) and 29 cm (11.5 inches), to the Great Black-backed Gull, at 1.75 kg (3.8 lbs) and 76 cm (30 inches).
Most gulls, particularly Larus species, are ground nesting carnivores, which will take live food or scavenge opportunistically. The live food often includes crabs and small fish. Apart from the kittiwakes, gulls are typically coastal or inland species, rarely venturing far out to sea. The large species take up to four years to attain full adult plumage, but two years is typical for small gulls.
Gulls — the larger species in particular — are resourceful and highly-intelligent birds, demonstrating complex methods of communication and a highly-developed social structure; for example, many gull colonies display mobbing behaviour, attacking and harassing would-be predators and other intruders.In addition, certain species (e.g. the Herring Gull) have exhibited tool use behaviour. Many species of gull have learned to co-exist successfully with man and have thrived in human habitats. Others rely on kleptoparasitism to get their food.
Two terms are in common usage among gull enthusiasts for subgroupings of the gulls:
Large white-headed gulls for the 16 Herring Gull-like species from Great Black-backed Gull to Lesser Black-backed Gull in the taxonomic list below
White-winged gulls for the two Arctic-breeding species Iceland Gull and Glaucous Gull

Chadriiformes


Charadriiformes is a diverse order of small to medium-large birds. It includes about 350 species and has members in all parts of the world. Most Charadriiformes live near water and eat invertebrates or other small animals; however, some are pelagic (sea birds), some occupy deserts and a few are found in thick forest.

Galliformes


Galliformes is an order of birds containing turkeys, grouse, chickens, quails, and pheasants. About 256 species are found worldwide.
These birds vary in size from the diminutive Asian Blue Quail (Coturnix chinensis) at 12.5 centimetres (5 in) long and weighing 28 to 40 grams (1 to 1.4 oz) to the largest extant Galliform species, the North American Wild Turkey (Meleagris gallopavo), wild specimens of which may weigh as much as 14 kilograms (about 30.5 lb) and may exceed 120 centimetres (47 in).
The Galliform bird species with the largest wing-span is most likely the Green Peafowl (Pavo muticus). Most Galliform genera are large in body with thick necks and moderately long legs and with rounded wings. Grouse, pheasants, francolins, and partridges are typical in their outwardly corpulent silhouettes.
Adult male Galliform birds have a sharp horny spur on the back of each leg, which they use for fighting.
Some Galliformes are adapted to grassland habitats and these genera are remarkable for their long, thin necks, long legs and large, wide wings. Thus Wild Turkey, Crested Fireback Pheasant, typical peafowl and Vulturine Guineafowl are outwardly similar in their convergent body types.
Vegetarian and slightly omnivorous genera are typically stoutly built and have short thick bills primarily adapted for foraging on the ground for rootlets or the consumption of other plant material such as heather shoots. The young birds will also take insects.
Peafowl, junglefowl and most of the sub-tropical pheasant genera have very different nutritional requirements from typical Palearctic genera. The Himalayan Monal (Lophophorus impejanus) has been observed digging in the rotting wood of deadfall in a similar manner to woodpeckers, even bracing itself with aid of its squared tail.

Anseriformes


The order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae (the screamers), Anseranatidae (the Magpie-goose), and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans.
All species in the order are highly adapted for an aquatic existence at the water surface. All are web-footed for efficient swimming (although some have subsequently become mainly terrestrial).

Neognathae


Neognaths (Neognathae) are birds that within the subclass Neornithes of the class Aves. The Neognathae include virtually all living birds; their sister taxon Paleognathae contains the tinamous - their only order capable of flight - as well as the flightless ratites.
There are nearly 10.000 species of neognaths. Since the late Cretaceous from where the earliest fossils are known, they have undergone adaptive radiation to produce the staggering diversity of form (especially of the bill and feet), function, and behavior that we see today. The Passeriformes (perching birds) are the largest order of land vertebrates, containing some 60% of living birds and being more than twice as diverse as rodents and about 5 times as diverse as Chiroptera (bats and flying foxes) which are the largest order of mammals. On the other hand, there are some very small orders, usually birds of very unclear relationships like the puzzling Hoatzin.
The neognaths have fused metacarpals, an elongate third finger, and 13 or fewer vertebrae. They differ from the Paleognathae in features like the structure of their jawsbones. "Neognathae" means "new jaws", but ironically it seems that the supposedly "more ancient" paleognath jaws are among the few apomorphic ("more advanced") features of this group as compared to the neognaths.

Kiwis


A kiwi is any of the species of flightless birds endemic to New Zealand of the genus Apteryx (the only genus in family Apterygidae). At around the size of a domestic chicken, kiwi are by far the smallest living ratites. All kiwi species are endangered. The kiwi is also a national symbol of New Zealand.

Emu


The Emu (pronunciation: IPA: /ˈiːmjuː/, Dromaius novaehollandiae, is the largest bird native to Australia and the only extant member of the genus Dromaius. It is also the second-largest extant bird in the world by height, after its ratite relative, the ostrich. The soft-feathered, brown, flightless birds reach up to 2 m (6.5 ft) in height. The Emu is common over most of mainland Australia, although it avoids heavily populated areas, dense forest and arid areas. Emus can travel great distances at a fast, economical trot and, if necessary, can sprint at 50 km/h (30 mph) for some distance at a time. They are opportunistically nomadic and may travel long distances to find food; they feed on a variety of plants and insects.
The Emu subspecies that previously inhabited Tasmania became extinct after the European settlement of Australia in 1788; and the distribution of the mainland subspecies has been influenced by human activities. Once common on the east coast, Emu are now uncommon; by contrast, the development of agriculture and the provision of water for stock in the interior of the continent have increased the range of the Emu in arid regions. Emus are farmed for their meat,

Ostrich


The Ostrich (Struthio camelus) is a large flightless bird native to Africa (and formerly the Middle East). It is the only living species of its family, Struthionidae, and its genus, Struthio. Ostriches share the order Struthioniformes with emus, kiwis, and other ratites. It is distinctive in its appearance, with a long neck and legs and the ability to run at speeds of about 65 km/h (40 mph), the top land speed of any bird.The Ostrich is The diet of the Ostrich mainly consists of seeds and other plant matter, though it eats insects. It lives in nomadic groups which contain between five and 50 birds. When threatened, the Ostrich will either hide itself by lying flat against the ground, the largest living species of bird and lays the largest egg of any bird species.
or will run away. If cornered, it can cause injury and death with a kick from its powerful legs. Mating patterns differ by geographical region, but territorial males fight for a harem of two to seven females.
The Ostrich is farmed around the world, particularly for its feathers, which are decorative and are also used for feather dusters. Its skin is used for leather and its meat marketed commercially.

Paleognathae


The Paleognathae or paleognaths ("old jaws") are one of the two living superorders of birds. The other living superorder is Neognathae.
The paleognaths contain several living orders of birds, the Tinamiformes (tinamous), the Apterygiformes (kiwis), Casuariiformes (cassowaries and emus), Rheiformes (rheas), and the Struthioniformes (ostriches). All but the tinamous are flightless. There are also many extinct orders: the Lithornithiformes, the Ambiornithiformes, the Gansuiformes, the Paleocursornithiformes, the Dinornithiformes (moas), and the Aepyornithiformes (elephant birds)
Most paleognaths have long necks and long legs, and are specialized for running rather than flight; indeed, the ratites are all completely flightless (with the partial exception of the tinamous). The group is not separated because of this though, it is rather based on the form of the jaw. Paleognaths other than tinamous are commonly known as ratites from the Latin word for raft, ratis, because they have a breastbone shaped like a raft

Distribution


Birds live and bree in most terrestrial habitats and on all seven continents, reaching their southern extreme in the Snow Petrel's breeding colonies up to 440 kilometres (270 mi) inland in Antarctica.The highest bird diversity occurs in tropical regions. It was earlier thought that this high diversity was the result ofd higher speciation rates in the tropics, however recent studies found higher speciation rates in the high latitudes that were offset by greater extinction rates than in the tropics.Several families of birds have adapted to life both on the world's oceans and in them, with some seabird species coming ashore only to breed. and some penguins recorded diving up to 300 metres (980 ft).
Many bird species have established breeding populations in areas to which they have been introduced by humans. Some of these introductions have been deliberate; the Ring-necked Pheasant, for example, has been introduced around the world as a game bird.Others have been accidental, such as the establishment of wild Monk Parakeets in several North American cities after their escape from captivity.Some species, including Cattle Egret,[35] Yellow-headed Caracara and Galah, have spread naturally far beyond their original ranges as agricultural practices created suitable new habitat.

Dinosaurs and the origin of birds

Fossil evidence and intensive biological analyses have demonstrated beyond any reasonable doubt that birds are theropod dinosaurs. More specifically, they are members of Maniraptora, a group of theropods which includes dromaeosaurs and oviraptorids, among others.As scientists discover more non-avian theropods that are closely related to birds, the previously clear distinction between non-birds and birds has become blurred. Recent discoveries in the Liaoning Province of northeast China, which demonstrate that many small theropod dinosaurs had feathers, contribute to this ambiguity.The consensus view in contemporary paleontology is that the birds, Aves, are the closest relatives of the deinonychosaurs, which include dromaeosaurids and troodontids. Together, these three form a group called Paraves. The basal dromaeosaur Microraptor has features which may have enabled it to glide or fly. The most basal deinonychosaurs are very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal, and/or may have been able to glide.The Late Jurassic Archaeopteryx is well-known as one of the first transitional fossils to be found and it provided support for the theory of evolution in the late 19th century. Archaeopteryx has clearly reptilian characters: teeth, clawed fingers, and a long, lizard-like tail, but it has finely preserved wings with flight feathers identical to those of modern birds. It is not considered a direct ancestor of modern birds, but is the oldest and most primitive member of Aves or Avialae, and it is probably closely related to the real ancestor. It has even been suggested that Archaeopteryx was a dinosaur that was no more closely related to birds than were other dinosaur groups .and that Avimimus was more likely to be the ancestor of all birds than Archaeopteryx.

Evolution and taxonomy


The first classification of birds was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae. Carolus Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use.Birds are categorised as the biological class Aves in Linnaean taxonomy. Phylogenetic taxonomy places Aves in the dinosaur clade Theropoda.Aves and a sister group, the clade Crocodilia, together are the sole living members of the reptile clade Archosauria. Phylogenetically, Aves is commonly defined as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica. Archaeopteryx, from the Kimmeridgian stage of the Late Jurassic (some 155–150 million years ago), is the earliest known bird under this definition. Others, including Jacques Gauthier and adherents of the Phylocode system, have defined Aves to include only the modern bird groups, excluding most groups known only from fossils, and assigning them, instead, to the Avialae. in part to avoid the uncertainties about the placement of Archaeopteryx in relation to animals traditionally thought of as theropod dinosaurs.
All modern birds lie within the subclass Neornithes, which has two subdivisions: the Paleognathae, containing mostly flightless birds like ostriches, and the wildly diverse Neognathae, containing all other birds.These two subdivisions are often given the rank of superorder,although Livezey & Zusi assigned them "cohort" rank. Depending on the taxonomic viewpoint, the number of known living bird species varies anywhere from 9,800 to 10,050

Birds


Birds (class Aves) are bipedal, endothermic (warm-blooded), vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the 5 cm (2 in) Bee Hummingbird to the 2.7 m (9 ft) Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Ma (million years ago), and the earliest known bird is the Late Jurassic Archaeopteryx, c 155–150 Ma. Most paleontologists regard birds as the only clade of dinosaurs that survived the Cretaceous–Tertiary extinction event approximately 65.5 Ma.
Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. All birds have forelimbs modified as wings and most can fly, with some exceptions including ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight. Some birds, especially corvids and parrots, are among the most intelligent animal species; a number of bird species have been observed manufacturing and using tools, and many social species exhibit cultural transmission of knowledge across generations.