78-526: And see text A passerine ( / ˈ p æ s ə r aɪ n / ) is any bird of the order Passeriformes ( / ˈ p æ s ə r ɪ f ɔːr m iː z / ; from Latin passer 'sparrow' and formis '-shaped') which includes more than half of all bird species. Sometimes known as perching birds , passerines generally have an anisodactyl arrangement of their toes (three pointing forward and one back), which facilitates perching. With more than 140 families and some 6,500 identified species, Passeriformes
156-510: A tui -sized bird) and several bones of at least one species of saddleback -sized bird have recently been described. These date from the Early to Middle Miocene ( Awamoan to Lillburnian , 19–16 mya). In Europe, perching birds are not too uncommon in the fossil record from the Oligocene onward, belonging to several lineages: That suboscines expanded much beyond their region of origin
234-744: A better sense of smell. A third stage of bird evolution starting with Ornithothoraces (the "bird-chested" avialans) can be associated with the refining of aerodynamics and flight capabilities, and the loss or co-ossification of several skeletal features. Particularly significant are the development of an enlarged, keeled sternum and the alula , and the loss of grasping hands. † Anchiornis † Archaeopteryx † Xiaotingia † Rahonavis † Jeholornis † Jixiangornis † Balaur † Zhongjianornis † Sapeornis † Confuciusornithiformes † Protopteryx † Pengornis Ornithothoraces † Enantiornithes Long-tailed widowbird The long-tailed widowbird ( Euplectes progne )
312-438: A bluish white bill. Females are rather inconspicuous, their feathers streaked tawny and black with pale patches on the chest, breast and back, narrow tail feathers, and horn-colored bills. When flying, male long-tailed widowbirds are readily visible due to their extremely long tails. Between six and eight of their twelve tail feathers are approximately half a metre (approximately 20 inches) long. The tail during flight display
390-494: A clearer picture of passerine origins and evolution that reconciles molecular affinities, the constraints of morphology, and the specifics of the fossil record. The first passerines are now thought to have evolved in the Southern Hemisphere in the late Paleocene or early Eocene , around 50 million years ago. The initial diversification of passerines coincides with the separation of the southern continents in
468-482: A considerable amount of time to gain acceptance because Darwin had little, if any, firm evidence that females did in fact choose mates based on characteristics they found attractive. It took ninety years after Darwin's initial proposal for the theory to be tested in what has become a classic example of behavioral ecology research. The male long-tailed widowbird has one of the most remarkable ornaments among passerine birds. Their tails, which are often more than half
546-473: A definition similar to "all theropods closer to birds than to Deinonychus ", with Troodon being sometimes added as a second external specifier in case it is closer to birds than to Deinonychus . Avialae is also occasionally defined as an apomorphy-based clade (that is, one based on physical characteristics). Jacques Gauthier , who named Avialae in 1986, re-defined it in 2001 as all dinosaurs that possessed feathered wings used in flapping flight , and
624-496: A distinct super-family Certhioidea . This list is in taxonomic order, placing related families next to one another. The families listed are those recognised by the International Ornithologists' Union (IOC). The order and the division into infraorders, parvorders, and superfamilies follows the phylogenetic analysis published by Carl Oliveros and colleagues in 2019. The relationships between the families in
702-483: A distinct variety of seeds, including those of Setaria sphacelata (twisted-leaf bristle grass), Paspalum dilatatum (common paspalum), Paspalum distichum (couch paspalum), Pennisetum clandestinum (Kikuyu grass), Triticum (wheat), Themeda triandra (rooigras), and Senecio juniperinus (groundsel). They also feed upon both insects, including species of beetles ( Coleoptera ), cicadas and aphids ( Hemiptera ), and spiders . Males defend territories in
780-468: A dozen and other species around five or six. The family Viduidae do not build their own nests, instead, they lay eggs in other birds' nests. The Passeriformes contain several groups of brood parasites such as the viduas , cuckoo-finches , and the cowbirds . The evolutionary history of the passerine families and the relationships among them remained rather mysterious until the late 20th century. In many cases, passerine families were grouped together on
858-442: A group called Paraves . Some basal members of Deinonychosauria, such as Microraptor , have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal , have been able to glide, or both. Unlike Archaeopteryx and the non-avialan feathered dinosaurs, who primarily ate meat, studies suggest that
SECTION 10
#1732766242191936-634: A group of warm-blooded vertebrates constituting the class Aves ( Latin: [ˈaveːs] ), 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 and they are split into 44 orders . More than half are passerine or "perching" birds. Birds have wings whose development varies according to species;
1014-410: A meter (20 inches) long, are the most extreme sexual ornament among Euplectes and seem to in fact be detrimental to the survival of the male. Thus, the tail appears to oppose forces of natural selection in the basic sense by decreasing survival in individuals who carry the trait. It was for this reason that researchers have chosen to focus their research into female choice on the confusing example of
1092-554: A metre (approximately 20 inches) long. Males have wingspans of approximately 127 to 147 mm (approximately 5 to 5.8 inches). Females have a rather subdued coloration. The upper portion of the female's body is streaked with buff or tawny and black. Female chests, breasts and flanks are slightly paler than their above coloring. The area under the wing-coverts is black and the females' tail feathers are narrow and pointed. Finally, their bills are horn-coloured. Non-breeding males are slightly larger than females, though they demonstrate
1170-407: A remarkably similar appearance. For the most part, these males are colored in the same manner as the females, except in that they are more broadly streaked above and below and have wings and wing shoulders with the morphology of the breeding class of males. Rarely, males in the non-breeding class have elongated brownish black tail feathers, though these feathers are substantially shorter than those of
1248-406: A sister group, the order Crocodilia , contain the only living representatives of the reptile clade Archosauria . During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica . However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, and
1326-717: 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)
1404-595: Is a species of bird in the family Ploceidae . The species are found in Angola , Botswana , the Democratic Republic of the Congo , Kenya , Lesotho , South Africa , Eswatini , and Zambia . The long-tailed widowbird is a medium-sized bird and one of the most common in the territories it inhabits. Adult breeding males are almost entirely black with orange and white shoulders (epaulets), long, wide tails, and
1482-540: 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
1560-482: Is currently divided into three suborders: Acanthisitti (New Zealand wrens), Tyranni , (suboscines) and Passeri (oscines or songbirds). The Passeri is now subdivided into two major groups recognized now as Corvides and Passerida respectively containing the large superfamilies Corvoidea and Meliphagoidea , as well as minor lineages, and the superfamilies Sylvioidea , Muscicapoidea , and Passeroidea but this arrangement has been found to be oversimplified. Since
1638-437: Is expanded vertically into a deep, long keel below the male as he flies with slow wingbeats 0.5 to 2 metres (20 to 78 inches) above his territory. Because of the seemingly large cost to such male ornaments, the long-tailed widowbird has been the subject of extensive research into the function and evolution of sexually selected traits. This research has demonstrated the existence of female choice in sexual selection and indicates
SECTION 20
#17327662421911716-615: Is found in the Kenyan highlands, the second in Angola , southern Zaire and Zambia , and the third in southern Africa . It is unknown when these populations were last in contact, however, and the central population differs most in morphology relative to the other two populations. The southern African population extends from the Eastern Cape (Transkei region) through the Free State, Lesotho, KwaZulu-Natal , and western Eswatini to
1794-429: 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. The first classification of birds
1872-905: Is more scant before the Pleistocene, from which several still-existing families are documented. Apart from the indeterminable MACN -SC-1411 (Pinturas Early/Middle Miocene of Santa Cruz Province, Argentina), an extinct lineage of perching birds has been described from the Late Miocene of California, United States: the Palaeoscinidae with the single genus Palaeoscinis . "Palaeostruthus" eurius (Pliocene of Florida) probably belongs to an extant family, most likely passeroidean . Acanthisitti – New Zealand wrens (1 family containing 7 species, only 2 extant) Tyranni – suboscines (16 families containing 1,356 species) Passeri – oscines (125 families containing 5,158 species) The Passeriformes
1950-417: Is most likely not the whole explanation, especially considering that prior to mating, females spend a great deal of time comparing males and, thus, do not rely on sighting them from a distance. As of this time, the exact function of epaulet in male long-tailed widowbirds is unknown. However, its use does resemble that of the red-winged blackbird , being displayed during courtship and threat displays. Thus,
2028-503: Is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. Over 40% of key traits found in modern birds evolved during the 60 million year transition from the earliest bird-line archosaurs to the first maniraptoromorphs , i.e. the first dinosaurs closer to living birds than to Tyrannosaurus rex . The loss of osteoderms otherwise common in archosaurs and acquisition of primitive feathers might have occurred early during this phase. After
2106-535: Is proven by several fossils from Germany such as a presumed broadbill ( Eurylaimidae ) humerus fragment from the Early Miocene (roughly 20 mya) of Wintershof , Germany, the Late Oligocene carpometacarpus from France listed above, and Wieslochia , among others. Extant Passeri super-families were quite distinct by that time and are known since about 12–13 mya when modern genera were present in
2184-516: Is synonymous to Avifilopluma. † Scansoriopterygidae † Eosinopteryx † Jinfengopteryx † Aurornis † Dromaeosauridae † Troodontidae Avialae Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora , a group of theropods which includes dromaeosaurids and oviraptorosaurs , among others. As scientists have discovered more theropods closely related to birds,
2262-442: Is the long-tailed widowbird . The chicks of passerines are altricial : blind, featherless, and helpless when hatched from their eggs. Hence, the chicks require extensive parental care. Most passerines lay colored eggs, in contrast with nonpasserines, most of whose eggs are white except in some ground-nesting groups such as Charadriiformes and nightjars , where camouflage is necessary, and in some parasitic cuckoos , which match
2340-458: Is the short-tailed pygmy tyrant , at 6.5 cm (2.6 in) and 4.2 g (0.15 oz). The foot of a passerine has three toes directed forward and one toe directed backward, called anisodactyl arrangement. The hind toe ( hallux ) is long and joins the leg at approximately the same level as the front toes. This arrangement enables passerine birds to easily perch upright on branches. The toes have no webbing or joining, but in some cotingas ,
2418-540: Is the largest order of birds and among the most diverse clades of terrestrial vertebrates , representing 60% of birds. Passerines are divided into three suborders : Acanthisitti (New Zealand wrens), Tyranni (composed mostly of South American suboscines), and Passeri (oscines or songbirds). Passerines originated in the Southern Hemisphere around 60 million years ago. Most passerines are insectivorous or omnivorous , and eat both insects and fruit or seeds. The terms "passerine" and "Passeriformes" are derived from
Passerine - Misplaced Pages Continue
2496-535: Is used by many scientists including adherents to the PhyloCode . Gauthier defined Aves to include only the crown group of the set of modern birds. This was done by excluding most groups known only from fossils , and assigning them, instead, to the broader group Avialae, on the principle that a clade based on extant species should be limited to those extant species and their closest extinct relatives. Gauthier and de Queiroz identified four different definitions for
2574-430: Is used to attract females rather than in direct contests among males, which is further supported by the fact that males do not expand their tails during flight displays during territorial contests. One explanation for why females favor long tails in males is that the expanded tail enlarges the lateral surface area of the male by 2–3 times, making him much more visible from far distances over open grassland. However, this
2652-652: The Corvida and numerous minor lineages make up songbird diversity today. Extensive biogeographical mixing happens, with northern forms returning to the south, southern forms moving north, and so on. Perching bird osteology , especially of the limb bones, is rather diagnostic. However, the early fossil record is poor because passerines are relatively small, and their delicate bones do not preserve well. Queensland Museum specimens F20688 ( carpometacarpus ) and F24685 ( tibiotarsus ) from Murgon, Queensland , are fossil bone fragments initially assigned to Passeriformes . However,
2730-722: 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- ornithuran dinosaurs. Many social species preserve knowledge across generations ( culture ). Birds are social, communicating with visual signals, calls, and songs , and participating in such behaviour 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
2808-635: The Old World warblers and Old World babblers have turned out to be paraphyletic and are being rearranged. Several taxa turned out to represent highly distinct lineages, so new families had to be established, some of theirs – like the stitchbird of New Zealand and the Eurasian bearded reedling – monotypic with only one living species. In the Passeri alone, a number of minor lineages will eventually be recognized as distinct superfamilies. For example,
2886-548: The Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Emberiza progne in his catalogue of the Planches Enluminées . The long-tailed widowbird is now one of 17 species placed in
2964-669: The Tiaojishan Formation of China, which has been dated to the late Jurassic period ( Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi , Xiaotingia zhengi , and Aurornis xui . The well-known probable early avialan, Archaeopteryx , dates from slightly later Jurassic rocks (about 155 million years old) from Germany . Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds but were later lost during bird evolution. These features include enlarged claws on
3042-629: The crows , do not sound musical to human beings. Some, such as the lyrebird , are accomplished mimics. The New Zealand wrens are tiny birds restricted to New Zealand , at least in modern times; they were long placed in Passeri. Most passerines are smaller than typical members of other avian orders. The heaviest and altogether largest passerines are the thick-billed raven and the larger races of common raven , each exceeding 1.5 kg (3.3 lb) and 70 cm (28 in). The superb lyrebird and some birds-of-paradise , due to very long tails or tail coverts, are longer overall. The smallest passerine
3120-913: The early Eocene . The New Zealand wrens are the first to become isolated in Zealandia , and the second split involved the origin of the Tyranni in South America and the Passeri in the Australian continent . The Passeri experienced a great radiation of forms in Australia. A major branch of the Passeri, the parvorder Passerida , dispersed into Eurasia and Africa about 40 million years ago, where they experienced further radiation of new lineages. This eventually led to three major Passerida lineages comprising about 4,000 species, which in addition to
3198-588: The genus Euplectes that was introduced by the English naturalist William John Swainson in 1829. The genus name combines the Ancient Greek eu "fine" or "good" and the Neo-Latin plectes "weaver". The specific progne is Latin for a "swallow. Three subspecies are recognised: The long-tailed widowbird has three geographically differentiated subspecies. These include delamerei , found in
Passerine - Misplaced Pages Continue
3276-480: The grasslands the species inhabits. Females have a long nesting period and survey these territories and the males that inhabit them prior to mate selection. Breeding takes place from February to July, reaching its peak in March and April. Females weave nests, shaped in large dome structures with a lining of seedheads, in the high grass within males' territories. The nests are placed 0.5–1 meters (19 to 40 inches) off
3354-445: The kinglets constitute a single genus with less than 10 species today but seem to have been among the first perching bird lineages to diverge as the group spread across Eurasia. No particularly close relatives of theirs have been found among comprehensive studies of the living Passeri, though they might be fairly close to some little-studied tropical Asian groups. Nuthatches , wrens , and their closest relatives are currently grouped in
3432-506: The scientific name of the house sparrow , Passer domesticus , and ultimately from the Latin term passer , which refers to sparrows and similar small birds. The order is divided into three suborders, Tyranni (suboscines), Passeri (oscines or songbirds), and the basal Acanthisitti . Oscines have the best control of their syrinx muscles among birds, producing a wide range of songs and other vocalizations, though some of them, such as
3510-400: The superb lyrebird has 16, and several spinetails in the family Furnariidae have 10, 8, or even 6, as is the case of Des Murs's wiretail . Species adapted to tree trunk climbing such as treecreepers and woodcreeper have stiff tail feathers that are used as props during climbing. Extremely long tails used as sexual ornaments are shown by species in different families. A well-known example
3588-765: The IOC but not in that study. The IOC families Alcippeidae and Teretistridae were not sampled in this study. Acanthisittidae (New Zealand wrens) Eurylaimidae (eurylaimid broadbills) Philepittidae (asites) Calyptomenidae (African and green broadbills) Pittidae (pittas) Sapayoidae (sapayoa) Melanopareiidae (crescent chests) Conopophagidae (gnateaters) Thamnophilidae (antbirds) Grallariidae (antpittas) Rhinocryptidae (tapaculos) Formicariidae (antthrushes) Scleruridae (leaftossers) Dendrocolaptidae (woodcreepers) Furnariidae (ovenbirds) Pipridae (manakins) Cotingidae (cotingas) Tityridae (tityras, becards) Bird Birds are
3666-518: The Transvaal plateau. The species just enters southeastern Botswana , but is most commonly found in the central highveld of South Africa. Long-tailed widowbirds are generally found in swampy grassland in flocks consisting of one or two males and a number of females. The males fly with their tails drooping and somewhat spread, and with slow regular movements of their wings. In wet weather, they are unable to fly due to their elongated tails. During
3744-428: The appearance of Maniraptoromorpha, the next 40 million years marked a continuous reduction of body size and the accumulation of neotenic (juvenile-like) characteristics. Hypercarnivory became increasingly less common while braincases enlarged and forelimbs became longer. The integument evolved into complex, pennaceous feathers . The oldest known paravian (and probably the earliest avialan) fossils come from
3822-600: The basis of morphological similarities that, it is now believed, are the result of convergent evolution , not a close genetic relationship. For example, the wrens of the Americas and Eurasia , those of Australia , and those of New Zealand look superficially similar and behave in similar ways, yet belong to three far-flung branches of the passerine family tree; they are as unrelated as it is possible to be while remaining Passeriformes. Advances in molecular biology and improved paleobiogeographical data gradually are revealing
3900-509: The birds that descended from them. Despite being currently one of the most widely used, the crown-group definition of Aves has been criticised by some researchers. Lee and Spencer (1997) argued that, contrary to what Gauthier defended, this definition would not increase the stability of the clade and the exact content of Aves will always be uncertain because any defined clade (either crown or not) will have few synapomorphies distinguishing it from its closest relatives. Their alternative definition
3978-467: The breeding class. Immature males and females are very similar in appearance to the adult female. However, immature males, much like adult non-breeding males, are slightly larger than adult females. The length of a female starts at 15cm and males have been recorded at 71cm in length, which has their tail included. Male weigh between 33–46 g and females weigh between 25–39 g. There are three known isolated populations of long-tailed widowbirds. The first
SECTION 50
#17327662421914056-512: The corvoidean and basal songbirds. The modern diversity of Passerida genera is known mostly from the Late Miocene onward and into the Pliocene (about 10–2 mya). Pleistocene and early Holocene lagerstätten (<1.8 mya) yield numerous extant species, and many yield almost nothing but extant species or their chronospecies and paleosubspecies. In the Americas , the fossil record
4134-665: The earliest members of Aves, is removed from this group, becoming a non-avian dinosaur instead. These proposals have been adopted by many researchers in the field of palaeontology and bird evolution , though the exact definitions applied have been inconsistent. Avialae, initially proposed to replace the traditional fossil content of Aves, is often used synonymously with the vernacular term "bird" by these researchers. † Coelurus † Ornitholestes † Ornithomimosauria † Alvarezsauridae † Oviraptorosauria Paraves Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used
4212-428: The elaborate ornamentation that males of some species exhibit despite detrimental costs to survival and seemingly negative consequences for reproductive success. He proposed two explanations for such traits' existences: these traits are useful in male-male combat or are preferred by females. Relative to the first of Darwin's theories on sexual selection, the process of female choice, though theoretically plausible, took
4290-451: The first avialans were omnivores . 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 was the first fossil to display both clearly traditional reptilian characteristics—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It
4368-640: The ground in the upper third of the high grass ( Eleusine jaegeri ), where the females raise their two to three young. Females often mate with the male within whose territories they nest. Females lay one to three eggs after mating, and these are pale bluish green and streaked with brown. They are usually around 23.5 millimeters (0.9 inches) by 16.5 mm (0.6 inches) in size. Charles Darwin first expressed his ideas on sexual selection and mate choice in his book The Descent of Man, and Selection in Relation to Sex in 1871 in response to questions surrounding
4446-864: The highlands of Kenya, delacouri , found in the Congo, Angola and Zambia, and progne , found in Botswana, South Africa, Eswatini and Lesotho. Some researchers have suggested the existence of long-tailed widowbird superspecies based on similarity in male nuptial plumage such as tail length, but this is the topic of some debate. Long-tailed widowbirds exhibit distinct sexual dimorphism . Males and females exhibit differences in behavior and morphological traits. Adult males are entirely black, including under their wing-coverts. Males' wing shoulders are orange red and their wing-coverts white. Their bills are bluish white. Males are known for their distinctly long tails, which contain twelve tail feathers. Of these twelve tail feathers, between six and eight are approximately half
4524-484: The long-tailed widowbird. Malte Andersson and colleagues tested Darwin's (and Fisher's) theory of female preference for ornamentation as the cause of extreme elongation of the male long-tailed widowbird's tail. They changed the length of males' tails and studied their relative mating success. Early in the breeding season, the territories of thirty-six males were mapped and the numbers of nests were counted. The experimenters used each male as his own control by subtracting
4602-666: The material is too fragmentary and their affinities have been questioned. Several more recent fossils from the Oligocene of Europe, such as Wieslochia , Jamna , Resoviaornis , and Crosnoornis , are more complete and definitely represent early passeriforms, and have been found to belong to a variety of modern and extinct lineages. From the Bathans Formation at the Manuherikia River in Otago , New Zealand, MNZ S42815 (a distal right tarsometatarsus of
4680-535: The mid-2000s, studies have investigated the phylogeny of the Passeriformes and found that many families from Australasia traditionally included in the Corvoidea actually represent more basal lineages within oscines. Likewise, the traditional three-superfamily arrangement within the Passeri has turned out to be far more complex and will require changes in classification. Major " wastebin " families such as
4758-407: The most reproductively successful. The tail females found most attractive were longer than those that occur in the natural setting. This outcome was shown to be the result of female choice rather than differences in male behavior resulting from shortened tails: males with shortened tails neither became less active in courtship display, nor did they give up their breeding territories. Thus, the tail
SECTION 60
#17327662421914836-451: The most successful, followed by the control (normal tail length) males, followed by the males with shortened tails. The result indicated that the long tail is favored by sexual selection through female choice of mates. Female preference for long tails is also seen in the red-collared widowbird . The Andersson experiment demonstrated that female long-tailed widowbirds prefer supernormal tails, as males with elongated tails were found to be
4914-569: The non-breeding season, long-tailed widowbirds congregate into flocks, which can be found roosting in reed beds. The long-tailed widowbird can be found at elevations up to 2,750 metres (9,022 feet) in the Drakensberg Mountains. The long-tailed widowbird's diet generally consists of seeds, supplemented occasionally by arthropods. The birds do most of their foraging in flocks on the ground, though they are occasionally observed hawking insects airily. The long-tailed widowbird feeds on
4992-444: The number of nests in each male's territory before treatment from the total of nests after treatment. This reduced the influence of initial variation among male territories on the outcome of the experiment. In a randomized block experiment, the color-ringed males were partitioned among nine groups of four males each. These groups were similar in territory quality and tail length. The tail of one randomly selected male within each group
5070-523: 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
5148-402: The outermost half) can be seen in the evolution of maniraptoromorphs, and this process culminated in the appearance of the pygostyle , an ossification of fused tail vertebrae. In the late Cretaceous, about 100 million years ago, the ancestors of all modern birds evolved a more open pelvis, allowing them to lay larger eggs compared to body size. Around 95 million years ago, they evolved
5226-517: The passerine host's egg. The vinous-throated parrotbill has two egg colors, white and blue, to deter the brood parasitic common cuckoo . Clutches vary considerably in size: some larger passerines of Australia such as lyrebirds and scrub-robins lay only a single egg, most smaller passerines in warmer climates lay between two and five, while in the higher latitudes of the Northern Hemisphere, hole-nesting species like tits can lay up to
5304-536: The previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the Liaoning Province of northeast China, which demonstrated many small theropod feathered dinosaurs , contributed to this ambiguity. The consensus view in contemporary palaeontology is that the flying theropods, or avialans , are the closest relatives of the deinonychosaurs , which include dromaeosaurids and troodontids . Together, these form
5382-517: The range size criterion put forward by BirdLife International which include that the extent of occurrence being less than 20,000 km (7722 miles ) combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation. The population is stable according to the population trend criterion, which requires a greater than 30% decline over ten years or three generations, and would not be considered vulnerable for this reason. While
5460-452: The same biological name "Aves", which is a problem. The authors proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below. They assigned other names to the other groups. Lizards & snakes Turtles Crocodiles Birds Under the fourth definition Archaeopteryx , traditionally considered one of
5538-507: The second and third toes are united at their basal third. The leg of passerine birds contains an additional special adaptation for perching. A tendon in the rear of the leg running from the underside of the toes to the muscle behind the tibiotarsus will automatically be pulled and tighten when the leg bends, causing the foot to curl and become stiff when the bird lands on a branch. This enables passerines to sleep while perching without falling off. Most passerine birds have 12 tail feathers but
5616-551: The second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering. Avialans diversified into a wide variety of forms during the Cretaceous period. Many groups retained primitive characteristics , such as clawed wings and teeth, though the latter were lost independently in a number of avialan groups, including modern birds (Aves). Increasingly stiff tails (especially
5694-506: The suborder Tyranni (suboscines) were all well determined but some of the nodes in Passeri (oscines or songbirds) were unclear owing to the rapid splitting of the lineages. Infraorder Eurylaimides : Old World suboscines Infraorder Tyrannides : New World suboscines Parvorder Furnariida Parvorder Tyrannida Relationships between living Passeriformes families based on the phylogenetic analysis of Oliveros et al (2019). Some terminals have been renamed to reflect families recognised by
5772-407: The total population size has not yet been quantified, it is not believed that the long-tailed widowbird is approaching the threshold for being considered vulnerable under the population size criterion (less than 10,000 mature individuals with a continuing decline estimated to be greater than 10% in ten years or three generations, or with a specified population structure). For these reasons, the species
5850-543: The trade-offs between sexual appeal and physical constraints with regard to the evolution of sexual ornaments. The long-tailed widowbird was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1779 in his Histoire Naturelle des Oiseaux from a bird collected in the Cape of Good Hope region of South Africa. The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in
5928-414: The two most conspicuous ornaments of the male birds in the two species may be favored by different forms of sexual selection: the tail of the long-tailed widowbird by female choice and the brightly colored epaulets of the long-tailed widowbird and red-winged blackbird by male contest competition. The long-tailed widowbird has a very large range, and so the species would not be classified as vulnerable under
6006-423: Was cut to about 14 centimeters (5 inches) in length. Each removed feather was then glued to the corresponding feather of another male, elongating his tail by 20 to 30 centimeters (8 to 12 inches). The two other males in the group served as controls. One had his tail cut and repaired using glue, while the other's tail was left unchanged. A clear pattern of success emerged, with males with the elongated tails being
6084-466: Was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae . Carl 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 clade Theropoda as an infraclass or a subclass, more recently a subclass. Aves and
#190809