Instruct: Given a question, retrieve passages that answer the question.
Query: What is the smallest species of bird?
With a mass of approximately and a length of 5 centimetres (2.0 in), the bee hummingbird ("Mellisuga helenae") is the world's smallest bird species and the smallest warm-blooded vertebrate. Called the "zunzún" in its native habitat on Cuba, it is lighter than a Canadian or U.S. penny. It is said that it is "more apt to be mistaken for a bee than a bird". The bee hummingbird eats half its total body mass and drinks eight times its total body mass each day. Its nest is 3 cm across.
The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than in length and weighs about . Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than in length.
In the lower Himalayas of northern Pakistan and Jammu and Kashmir, along with the brown fish owl, the Eurasian eagle-owl at the limit of its distribution may co-exist with at least two to three other eagle-owls. One of these, the dusky eagle-owl ("B. coromandus") is smaller, with more uniform tan-brownish plumage, untidy uniform light streaking rather than the Eurasian’s dark streaking below and an even less well-defined facial disc. The dusky is usually found in slightly more enclosed woodland areas than Eurasian eagle-owls. Another is possibly the spot-bellied eagle-owl ("Bubo nipalensis"), which is strikingly different looking, with stark brown plumage, rather than the warm hues typical of the Eurasian, bold spotting on a whitish background on the belly, and somewhat askew ear tufts that are bold white with light brown crossbars on the front. It is possible that both species occur in some parts of the Himalayan foothills but they are not currently verified to occur in the same area, in part because of the spot-bellied’s preference for dense, primary forest. Most similar, with basically the same habitat preferences and the only one verified to co-occur with the Eurasian eagle-owls of the race "B. b. turcomanus" in Kashmir is the Indian eagle-owl ("B. bengalensis"). The Indian species is smaller with a bolder blackish facial disc border, more rounded and relatively smaller wings and partially unfeathered toes. Far to the west, the pharaoh eagle-owl ("B. ascalaphus") also seemingly overlaps in range with the Eurasian, in at least the country of Jordan. Although also relatively similar to the Eurasian eagle-owl, the pharaoh is distinguished by its smaller size, paler, more washed-out plumage and the diminished size of its ear-tufts.
Group D
Over 600 species of bird have been recorded in Japan and more than 250 of these breed. A number of birds are endemic including the Japanese woodpecker ("Picus awokera"), copper pheasant ("Syrmaticus soemmerringii") and Japan's national bird, the green pheasant ("Phasianus versicolor"). Several species are unique to the smaller islands including the Okinawa rail ("Gallirallus okinawae"), Izu thrush ("Turdus celaenops") and Bonin white-eye ("Apalopteron familiare "). Most of the non-endemic birds are shared with China but a few originate in Siberia or south-east Asia.
Sparrows are small passerine birds. In general, sparrows tend to be small, plump, brown or grey birds with short tails and short powerful beaks. Sparrows are seed eaters, but they also consume small insects. There are 35 species worldwide and 2 species which occur in Malaysia.
The long-tailed finch ("Poephila acuticauda") is a common species of estrildid finch found in Australia; also known as the blackheart finch, shaft-tail finch, Heck's grassfinch, Heck's grass finch, and Heck's finch. It is a predominantly fawn-coloured bird with a pale grey head and prominent black bib and eyes. It has an estimated global extent of occurrence of 1,000,000–10,000,000 km. It inhabits dry savannah habitats in Australia and adapts readily to aviculture. The IUCN has classified the species as being of least concern.
This is a list of the fastest flying birds in the world. A bird's velocity is necessarily variable; a hunting bird will reach much greater speeds while diving to catch prey than when gliding. The bird with the greatest airspeed velocity is the Peregrine falcon, able to exceed 321.8 km/h (200 mph) in its hunting dives. The greatest self-powered horizontal speed is achieved by Homing Racing Pigeons. They can fly 1100 km (700 miles) in a single day, and they have been recorded flying at 177 km/h (110 miles per hour), making them the birds with the fastest speed ever recorded on a self-powered flight, and the fastest endurance flight.
The Virginia rail probe with its bill in mud or shallow water, also picking up food by sight. It mainly eat insects and other aquatic invertebrates, like beetles, flies, dragonflies, crayfish, snails and earthworms. It can also eat aquatic animals like frogs, fish and some small snakes, as well as seeds. Animal preys constitute the biggest part of this bird's diet, but vegetation contributes to its diet in the fall and winter.
The Paridae are mainly small stocky woodland species with short stout bills. Some have crests. They are adaptable birds, with a mixed diet including seeds and insects. Four species have been recorded in Washington.Order: PasseriformesFamily: Aegithalidae
Group C
The family's common name is derived from a length of "free" tail, projecting beyond the end of the uropatagium—the membrane that connects the base of the tail to the hind legs. The tail is usually best seen when resting. A special ring of cartilage slides up or down the tail vertebrae by muscular action to stretch or retract the tail membrane. This gives many species a degree of fine tuning in their flight maneuvers to rival their day-flying ecological equivalents, such as swifts, swallows, and martins. As a result, these animals include the fastest-flying of all bat species among their number. The dental formula of free-tailed bats varies between species:
The forests are home to a number of endemic species including two flightless birds that no longer survive in the lowland areas of the island, these are the western weka and the largest kiwi, the great spotted kiwi. The varied habitats in the region support a mixture of other birds found here include the kea, the New Zealand kaka parrot" (Nestor meridionalis)", the New Zealand pigeon or kereru "(Hemiphaga novaeseelandiae)" and the New Zealand falcon or karearea "(Falco novaeseelandiae)". Farewell Spit in particular is an important site for wading birds and is on a migration route. 
The area is also rich in invertebrates including almost half of the known species of amber snails "(Powelliphanta)".
The beel is a natural habitat to many varieties of birds. 219 species of birds including more than 70 migratory species are reported in the beel area. The largest congregations of aquatic birds can be seen, particularly in winter, with a reported recorded count of 19,000 water birds in a day. Some of the globally threatened species of birds like spotbilled pelican ("Pelecanus philippensis"), lesser adjutant stork ("Leptoptilos javanicus"), Baer’s pochard ("Aythya baeri"), Pallas' sea eagle ("Haliaeetus leucogaster"), greater adjutant stork ("Leptoptilos dubius").
The birds of New Zealand evolved into an avifauna that included a large number of endemic species. As an island archipelago New Zealand accumulated bird diversity and when Captain James Cook arrived in the 1770s he noted that the bird song was deafening. The mix includes species with unusual biology such as the kakapo which is the world's only flightless, nocturnal, lek breeding parrot, but also many species that are similar to neighboring land areas. Some of the more well known and distinctive bird species in New Zealand are the kiwi, kea, takahe, kakapo, mohua, tui and the bellbird. The tuatara is a notable reptile endemic to New Zealand.
This rail is a skulking species, its streaked plumage making it difficult to see in its wetland habitat. Its laterally compressed body allows it to slip though the densest vegetation, and it will "freeze" if surprised in the open. It walks with a high-stepping gait, although it adopts a crouch when it runs for cover. It swims, when necessary, with the jerky motion typical of rails, and it flies short distances low over the reeds with its long legs dangling. Although their flight looks weak, water rails are capable of long sustained flights during their nocturnal migrations, and are sometimes killed in collisions with lighthouses or wires. British-ringed birds have been recovered from as far away as Poland, Czechoslovakia and Sweden.
Recent research by Zamora "et al." (2006) has revealed that the desert finch is more closely related to the greenfinches of the genus "Carduelis" (or "Chloris", if "Carduelis" is split up) as indicated by DNA sequence analysis, vocalizations, and the presence of a black eye-stripe. Genetically, it seems very close to the common ancestor of the greenfinches. It may be that the latter evolved from a desert form and later developed the green plumage, or that the common ancestor of the greenfinches and the desert finch (which lived around 6 million years ago) was a species of semiarid habitat which subsequently diverged into a truly desert-adapted lineage, today represented by the desert finch, and the ancestor of a woodlands lineage, the greenfinches.
A shrike is a passerine bird of the family Laniidae known for catching insects, small birds or mammals, and impaling their bodies on thorns. This helps them tear the flesh into small convenient fragments, and serves as a "larder" so that the shrike can return to feed later. A typical shrike's beak is hooked, like a bird of prey, reflecting its predatory nature. There are 32 species worldwide, six in Southern Africa.Order: PasseriformesFamily: Prionopidae
This is a monotypic species. All tinamou are from the family Tinamidae, and in the larger scheme are also ratites. Unlike other ratites, tinamous can fly, although in general, they are not strong fliers. All ratites evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds.
The passerines (perching birds) alone account for well over 5000 species. In total there are about 10,000 species of birds described worldwide, though one estimate of the real number places it at almost twice that.
The Fringillidae are all seed-eaters with stout conical bills. They have similar skull morphologies, nine large primaries, 12 tail feathers and no crop. In all species, the female builds the nest, incubates the eggs, and broods the young. Finches are divided into two subfamilies, the Carduelinae, containing around 28 genera with 141 species and the Fringillinae containing a single genus, "Fringilla", with three species: the chaffinch ("F. coelebs"), the Tenerife blue chaffinch ("F. teydea"), and the brambling ("F. montifringilla"). Fringilline finches raise their young almost entirely on arthropods, while the cardueline finches raise their young on regurgitated seeds.
Wrens are medium-small to very small birds. The Eurasian wren is among the smallest birds in its range, while the smaller species from the Americas are among the smallest passerines in that part of the world. They range in size from the white-bellied wren, which averages under and , to the giant wren, which averages about and weighs almost . The dominating colors of their plumage are generally drab, composed of gray, brown, black, and white, and most species show some barring, especially to tail and/or wings. No sexual dimorphism is seen in the plumage of wrens, and little difference exists between young birds and adults. All have fairly long, straight to marginally decurved bills.
This petite species is not only the smallest North American "Spinus" finch, it may be the smallest true finch in the world. Some sources list more subtropical "Spinus" species as slightly smaller on average, including the Andean siskin. This species ranges from in length and can weigh from . Among standard measurements, the wing chord is , the tail is , the bill is and the tarsus is . There is a slight NW-SE cline in size, with the largest birds from Mexico and south being up to one-fifth larger than the smallest from the extreme NW of its range; this effect is more pronounced in females. There is also considerable variation in the amount of black on head and back in males, and thus three subspecies have been proposed. But this variation too seem to be simple and clinal changes in allele frequency, and thus the "subspecies" might be better considered morphs or geographical forms.
Males are easily recognized by their bright yellow underparts and big white patches in the tail (outer rectrices) and on the wings (the base of the primaries). They range from having solid black from the back to the upper head including the ear-coverts to having these regions medium green; each of the back, crown and ear regions varies in darkness rather independently though as a rule the ears are not darker than the rest. In most of the range dark psaltria birds (Arkansas goldfinch) predominate. The light birds are termed hesperophilus and are most common in the far western U.S. and northwestern Mexico.
Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather.
Apart from the giant teratorn "Argentavis magnificens", the biggest of the pseudotooth birds were the largest flying birds known. Almost all of their remains from the Neogene are immense, but in the Paleogene there were a number of pelagornithids that were around the size of a great albatross (genus "Diomedea") or even a bit smaller. The undescribed species provisionally called "Odontoptila inexpectata" – from the Paleocene-Eocene boundary of Morocco – is the smallest pseudotooth bird discovered to date and was just a bit larger than a white-chinned petrel ("Procellaria aequinoctialis").