87-420: Plumas (Spanish for " feathers ") may refer to: Canada Mexico United States Feathers 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 an example of a complex evolutionary novelty. They are among
174-442: A follicle in the skin . The basal part of the calamus is without vanes. This part is embedded within the skin follicle and has an opening at the base (proximal umbilicus) and a small opening on the side (distal umbilicus). Hatchling birds of some species have a special kind of natal down feathers (neossoptiles) which are pushed out when the normal feathers (teleoptiles) emerge. Flight feathers are stiffened so as to work against
261-472: A bird's diet and the level found in its feathers, with the proportion of the chemicals found in its feathers remaining relatively constant (and relatively high for some metals). Mutations in the genes that control the formation of down feathers have been recorded in a German White Leghorn chicken flock. Although the elements of a normal down feather are present, a hyperkeratosis of the feather's horny sheath after 16–17 days of incubation results in
348-432: A bird's head, neck and trunk. Filoplumes are entirely absent in ratites . In some passerines, filoplumes arise exposed beyond the pennaceous feathers on the neck. The remiges, or flight feathers of the wing, and rectrices, or flight feathers of the tail, are the most important feathers for flight. A typical vaned feather features a main shaft, called the rachis . Fused to the rachis are a series of branches, or barbs ;
435-498: A few groups of birds. Down is a fine thermal insulator and padding , used in goods such as jackets , bedding ( duvets and featherbeds ), pillows and sleeping bags . The discovery of feathers trapped in ancient amber suggests that some species of non-avian dinosaur likely possessed down-like feathers. The word down comes from the Old Norse word dúnn , which had the same meaning as its modern equivalent. The down feather
522-435: A given ounce of down (in /oz). To measure fill power, an ounce of down is placed into a graduated cylinder , and a small weight is dropped in on top of it; the volume below the weight indicates the fill power. Eiderdown has the highest fill power, at 1200. However, even down with a fill power as low as 550 still provides reasonably good insulation. Higher fill-power downs will thus insulate better than lower fill-power downs of
609-449: A large rachis but few barbs. Rictal bristles are found around the eyes and bill. They may serve a similar purpose to eyelashes and vibrissae in mammals . Although there is as yet no clear evidence, it has been suggested that rictal bristles have sensory functions and may help insectivorous birds to capture prey. In one study, willow flycatchers ( Empidonax traillii ) were found to catch insects equally well before and after removal of
696-467: A meal. As with fish, the top and bottom colors may be different, in order to provide camouflage during flight. Striking differences in feather patterns and colors are part of the sexual dimorphism of many bird species and are particularly important in the selection of mating pairs. In some cases, there are differences in the UV reflectivity of feathers across sexes even though no differences in color are noted in
783-559: A means for determining the evolutionary relationships of bird families. Species that incubate their own eggs often lose their feathers on a region of their belly, forming a brooding patch . The colors of feathers are produced by pigments, by microscopic structures that can refract , reflect, or scatter selected wavelengths of light, or by a combination of both. Most feather pigments are melanins (brown and beige pheomelanins , black and grey eumelanins ) and carotenoids (red, yellow, orange); other pigments occur only in certain taxa –
870-579: A needle and thread without anesthetic. Although live-plucking is illegal in Canada, the United States and Europe, it is known to occur in two European countries (Poland and Hungary) and in China. Public sentiment against the practice has, in some countries, been strong. IKEA and clothing manufacturer Patagonia have altered product lines to eliminate the use (or possible use) of live-plucked down. In
957-544: A number of industrial applications as a medium for culturing microbes, biodegradable polymers, and production of enzymes. Feather proteins have been tried as an adhesive for wood board. Some groups of Native people in Alaska have used ptarmigan feathers as temper (non-plastic additives) in pottery manufacture since the first millennium BC in order to promote thermal shock resistance and strength. Eagle feathers have great cultural and spiritual value to Native Americans in
SECTION 10
#17327689979781044-462: A pennibrachium (a wing-like structure consisting of elongate feathers), while younger ones did not. This suggests that the pennibrachium was a secondary sex characteristic and likely had a sexual function. Several genes have been found to determine feather development. They will be key to understand the evolution of feathers. For instance, some genes convert scales into feathers or feather-like structures when expressed or induced in bird feet, such as
1131-658: A popular trend as a hairstyle accessory, with feathers formerly used as fishing lures now being used to provide color and style to hair. Feather products manufacturing in Europe has declined in the last 60 years, mainly due to competition from Asia. Feathers have adorned hats at many prestigious events such as weddings and Ladies Day at racecourses (Royal Ascot). The functional view on the evolution of feathers has traditionally focused on insulation, flight and display. Discoveries of non-flying Late Cretaceous feathered dinosaurs in China, however, suggest that flight could not have been
1218-450: A powder puff to apply the powder. Waterproofing can be lost by exposure to emulsifying agents due to human pollution. Feathers can then become waterlogged, causing the bird to sink. It is also very difficult to clean and rescue birds whose feathers have been fouled by oil spills . The feathers of cormorants soak up water and help to reduce buoyancy, thereby allowing the birds to swim submerged. Bristles are stiff, tapering feathers with
1305-444: A powder, or "feather dust", among the feathers. These feathers grow continuously and are not moulted. In other species, powder grains come from cells that surround the barbules of growing feathers. These specialized feathers are typically scattered among ordinary down feathers, though in some species, they occur in clusters. All parrots have powder down, with some species (including the mealy amazons ) producing copious amounts. It
1392-436: A role in the evolution of powered flight. The coloration of feathers is believed to have evolved primarily in response to sexual selection . In fossil specimens of the paravian Anchiornis huxleyi and the pterosaur Tupandactylus imperator , the features are so well preserved that the melanosome (pigment cells) structure can be observed. By comparing the shape of the fossil melanosomes to melanosomes from extant birds,
1479-711: A waste product of poultry farming, including chickens , geese , turkeys , pheasants , and ostriches . These feathers are dyed and manipulated to enhance their appearance, as poultry feathers are naturally often dull in appearance compared to the feathers of wild birds. Feather derives from the Old English "feþer", which is of Germanic origin; related to Dutch "veer" and German "Feder", from an Indo-European root shared by Sanskrit's "patra" meaning 'wing', Latin's "penna" meaning 'feather', and Greek's "pteron", "pterux" meaning 'wing'. Because of feathers being an integral part of quills , which were early pens used for writing,
1566-427: A waterproofing agent and a feather conditioner . Powder down has evolved independently in several taxa and can be found in down as well as in pennaceous feathers. They may be scattered in plumage as in the pigeons and parrots or in localized patches on the breast, belly, or flanks, as in herons and frogmouths. Herons use their bill to break the powder down feathers and to spread them, while cockatoos may use their head as
1653-402: Is actually more closely related to Ornithischia , to which it formed the sister group within the clade Ornithoscelida . The study also suggested that if the feather-like structures of theropods and ornithischians are of common evolutionary origin then it would be possible that feathers were restricted to Ornithoscelida. If so, then the origin of feathers would have likely occurred as early as
1740-458: Is also found in herons and tinamous . The dust produced from powder down feathers is a known allergen in humans. The loose structure of down feathers traps air, which helps to insulate the bird against heat loss and contributes to the buoyancy of waterbirds. Species that experience annual temperature fluctuations typically have more down feathers following their autumn moult. There is some evidence that down feathers may also help to decrease
1827-434: Is away from the nest, particularly as the birds often draw the feathers over their eggs before leaving. Because a bird can eliminate heavy metals in its feathers and because feathers can be collected non-invasively and stored indefinitely, down feathers can be used to check for evidence of metal contamination in the bird's environment. Studies have shown a high level of correlation between the level of metal contamination in
SECTION 20
#17327689979781914-506: Is called by some the Dyck texture. Melanin is often involved in the absorption of light; in combination with a yellow pigment, it produces a dull olive-green. In some birds, feather colors may be created, or altered, by secretions from the uropygial gland , also called the preen gland. The yellow bill colors of many hornbills are produced by such secretions. It has been suggested that there are other color differences that may be visible only in
2001-408: Is caused by defective pigment production, though structural coloration will not be affected (as can be seen, for example, in blue-and-white budgerigars ). The blues and bright greens of many parrots are produced by constructive interference of light reflecting from different layers of structures in feathers. In the case of green plumage, in addition to yellow, the specific feather structure involved
2088-568: Is considered presumptuous. During the 18th, 19th, and early 20th centuries, there was a booming international trade in plumes for extravagant women's hats and other headgear (including in Victorian fashion ). Frank Chapman noted in 1886 that feathers of as many as 40 species of birds were used in about three-fourths of the 700 ladies' hats that he observed in New York City. For instance, South American hummingbird feathers were used in
2175-531: Is considered to be the most "straightforward" of all feather types. It has a short or vestigial rachis (shaft), few barbs , and barbules that lack hooks. There are three types of down: natal down, body down and powder down. Natal down is the layer of down feathers that cover most birds at some point in their early development. Precocial nestlings are already covered with a layer of down when they hatch, while altricial nestlings develop their down layer within days or weeks of hatching. Megapode hatchlings are
2262-581: Is from Iceland. According to the International Down and Feather Bureau , eiderdown contributes only a small, but lucrative, portion of the world's total down production, estimated at 175,000 tonnes annually. An eiderdown duvet requires from 600 to 1,600 grams of eiderdown fill; a simple 800 gram duvet sells for about 640,000 Icelandic króna (US$ 5,116) as of 2021. In Iceland and Scandinavia, colonies of more than 5,000 birds sometimes develop in "farmed" areas, while in some protected areas of
2349-427: Is likely that non-avian dinosaur species utilized plumage patterns for similar functions as modern birds before the origin of flight. In many cases, the physiological condition of the birds (especially males) is indicated by the quality of their feathers, and this is used (by the females) in mate choice . Additionally, when comparing different Ornithomimus edmontonicus specimens, older individuals were found to have
2436-406: Is only a small fraction of the total (less than 1% in 2011), a 2009 Swedish documentary reported that it might be as much as 50–80% of the total supply, a figure supported by IKEA and an industry representative, but disputed by organizations within the industry. The documentary also shows birds lying on the floor with large flesh wounds from the plucking, after which the wounds were stitched using
2523-436: Is removed per nest. When the eggs have hatched and the young have left the area, the remaining down and breast feathers are gathered, typically resulting in another 0.75 oz (21 g) of lower quality feathers per nest. In general, 50–60 nests will produce about one kilogram (2.2 pounds) of down feathers. No more than four tonnes of eiderdown is collected from wild nests each year. Approximately 70% of that harvest
2610-542: Is suppressed during embryological development of the alligator and so is not present in the scales of mature alligators. The presence of this homologous keratin in both birds and crocodilians indicates that it was inherited from a common ancestor. This may suggest that crocodilian scales, bird and dinosaur feathers, and pterosaur pycnofibres are all developmental expressions of the same primitive archosaur skin structures; suggesting that feathers and pycnofibers could be homologous. Molecular dating methods in 2011 show that
2697-479: The Indian peacock have been used in traditional medicine for snakebite, infertility, and coughs. Members of Scotland's Clan Campbell are known to wear feathers on their bonnets to signify authority within the clan. Clan chiefs wear three, chieftains wear two and an armiger wears one. Any member of the clan who does not meet the criteria is not authorized to wear feathers as part of traditional garb and doing so
Plumas - Misplaced Pages Continue
2784-471: The Middle Triassic , though this has been disagreed upon. The lack of feathers present in large sauropods and ankylosaurs could be that feathers were suppressed by genomic regulators. Several studies of feather development in the embryos of modern birds, coupled with the distribution of feather types among various prehistoric bird precursors, have allowed scientists to attempt a reconstruction of
2871-581: The Novaya Zemlya archipelago, nest densities exceed 13,000 per hectare (5,300/acre). On the other hand, the more nomadic indigenous peoples of Arctic Canada did not see down production as a reasonable source of income and tended to overexploit eider nests with "indifferent" collection of down feathers from the nests. Although the down feathers of various species of wildfowl , gulls and other seabirds have historically been used for insulation, most now come from domestic geese . Some 70 percent of
2958-564: The United States and First Nations peoples in Canada as religious objects. In the United States, the religious use of eagle and hawk feathers is governed by the eagle feather law , a federal law limiting the possession of eagle feathers to certified and enrolled members of federally recognized Native American tribes. In South America, brews made from the feathers of condors are used in traditional medications. In India, feathers of
3045-423: The millinery and dressmaking trades. Though it is still called by the same name, today's "marabou" (sometimes spelled "marabout"), comes from domestic turkeys, as marabou storks are protected. For centuries, humans across the globe have used down feathers for insulation. Russian documents from the 1600s list "bird down" among the goods sold to Dutch merchants, and communities in northern Norway began protecting
3132-494: The ornithischian dinosaurs Tianyulong and Psittacosaurus . The exact nature of these structures is still under study. However, it is believed that the stage-1 feathers (see Evolutionary stages section below) such as those seen in these two ornithischians likely functioned in display. In 2014, the ornithischian Kulindadromeus was reported as having structures resembling stage-3 feathers. The likelihood of scales evolving on early dinosaur ancestors are high. However, this
3219-401: The penguins , ratites and screamers. In most birds the feathers grow from specific tracts of skin called pterylae ; between the pterylae there are regions which are free of feathers called apterylae (or apteria ). Filoplumes and down may arise from the apterylae. The arrangement of these feather tracts, pterylosis or pterylography, varies across bird families and has been used in the past as
3306-401: The α-keratins of mammalian hair , horns and hooves . The exact signals that induce the growth of feathers on the skin are not known, but it has been found that the transcription factor cDermo-1 induces the growth of feathers on skin and scales on the leg. There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath
3393-560: The Ghost Dance, or an eagle, which is ubiquitously sacred. Zuni prayer sticks are also made using eagle down. While eagle feathers belong to the Sun Priest, who plants them to the sun, other priests could use them if rain was needed, as the down is said to suggest "fleecy clouds that gather on the horizon before rain". The Hopi rub eagle down feathers over rattlesnakes collected for Snake Dances, in an effort to soothe and calm
3480-413: The United States, Federal Trade Commission regulations require that any product labeled "100% Down" must contain only down feathers, while products labeled simply "Down" can contain a mixture of fiber and feathers. In addition, products labeled as "Goose Down" must contain at least 90% goose down, 10% goose feathers. Down insulation is rated by fill power , which is the number of cubic inches displaced by
3567-451: The ability to expand from a compressed, stored state to trap large amounts of compartmentalized, insulating air. Feathers of large birds (most often geese ) have been and are used to make quill pens. Historically, the hunting of birds for decorative and ornamental feathers has endangered some species and helped to contribute to the extinction of others. Today, feathers used in fashion and in military headdresses and clothes are obtained as
Plumas - Misplaced Pages Continue
3654-445: The air in the downstroke but yield in other directions. It has been observed that the orientation pattern of β-keratin fibers in the feathers of flying birds differs from that in flightless birds: the fibers are better aligned along the shaft axis direction towards the tip, and the lateral walls of rachis region show structure of crossed fibers. Feathers insulate birds from water and cold temperatures. They may also be plucked to line
3741-416: The ancestral state of dinosaurs. In 2010, a carcharodontosaurid named Concavenator corcovatus was found to have remiges on the ulna suggesting it might have had quill-like structures on the ams. However, Foth et al. 2014 disagress with the publication where they point out that the bumps on the ulna of Concavenator are on the anterolateral which is unlike remiges which are in a posterolateral on
3828-421: The barbs themselves are also branched and form the barbules . These barbules have minute hooks called barbicels for cross-attachment. Down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular calamus (or quill ) which inserts into
3915-798: The characteristics that distinguish the extant birds from other living groups. Although feathers cover most of the bird's body, they arise only from certain well-defined tracts on the skin. They aid in flight, thermal insulation, and waterproofing. In addition, coloration helps in communication and protection . The study of feathers is called plumology (or plumage science ). People use feathers in many ways that are practical, cultural, and religious. Feathers are both soft and excellent at trapping heat ; thus, they are sometimes used in high-class bedding , especially pillows , blankets , and mattresses . They are also used as filling for winter clothing and outdoor bedding, such as quilted coats and sleeping bags . Goose and eider down have great loft ,
4002-399: The color and pattern of the feathers on Anchiornis and Tupandactylus could be determined. Anchiornis was found to have black-and-white-patterned feathers on the forelimbs and hindlimbs, with a reddish-brown crest. This pattern is similar to the coloration of many extant bird species, which use plumage coloration for display and communication, including sexual selection and camouflage. It
4089-421: The darker birds confirmed Gloger's rule . Although sexual selection plays a major role in the development of feathers, in particular, the color of the feathers it is not the only conclusion available. New studies are suggesting that the unique feathers of birds are also a large influence on many important aspects of avian behavior, such as the height at which different species build their nests. Since females are
4176-584: The down feathers of an eagle are important gifts given by the bird to the story's hero . In the Ghost Dance , a religious movement that has become particularly widespread among the Indigenous peoples of the Great Plains and Canadian Prairies , each dancer holds a painted feather tipped with a down feather painted with another color; the feathers are generally those of a crow , which is sacred to
4263-402: The dual function of helping to insulate the eggs and exposing the female's brood patch —an area of bare skin, rich in blood vessels, which transmits heat very efficiently. Of the various items birds use to line their nests, down feathers provide the most effective insulation, though only when dry; wet down is the least effective insulator. Down may also help camouflage the eggs when the female
4350-490: The evolution of feathers—theropods with highly derived bird-like characteristics occurred at a later time than Archaeopteryx —suggesting that the descendants of birds arose before the ancestor. However, the discovery of Anchiornis huxleyi in the Late Jurassic Tiaojishan Formation (160 MYA) in western Liaoning in 2009 resolved this paradox. By predating Archaeopteryx , Anchiornis proves
4437-614: The evolution of proto-birds like Archaeopteryx and Microraptor zhaoianus . Another theory posits that the original adaptive advantage of early feathers was their pigmentation or iridescence, contributing to sexual preference in mate selection. Dinosaurs that had feathers or protofeathers include Pedopenna daohugouensis and Dilong paradoxus , a tyrannosauroid which is 60 to 70 million years older than Tyrannosaurus rex . The majority of dinosaurs known to have had feathers or protofeathers are theropods , however featherlike "filamentous integumentary structures" are also known from
SECTION 50
#17327689979784524-512: The existence of a modernly feathered theropod ancestor, providing insight into the dinosaur-bird transition. The specimen shows distribution of large pennaceous feathers on the forelimbs and tail, implying that pennaceous feathers spread to the rest of the body at an earlier stage in theropod evolution. The development of pennaceous feathers did not replace earlier filamentous feathers. Filamentous feathers are preserved alongside modern-looking flight feathers – including some with modifications found in
4611-538: The expense of health. A bird's feathers undergo wear and tear and are replaced periodically during the bird's life through molting . New feathers, known when developing as blood, or pin feathers , depending on the stage of growth, are formed through the same follicles from which the old ones were fledged. The presence of melanin in feathers increases their resistance to abrasion. One study notes that melanin based feathers were observed to degrade more quickly under bacterial action, even compared to unpigmented feathers from
4698-419: The face that were used as tactile sensors. While feathers have been suggested as having evolved from reptilian scales , there are numerous objections to that idea, and more recent explanations have arisen from the paradigm of evolutionary developmental biology . Theories of the scale-based origins of feathers suggest that the planar scale structure was modified for development into feathers by splitting to form
4785-411: The feathers of extant diving birds – in 80 million year old amber from Alberta. Two small wings trapped in amber dating to 100 mya show plumage existed in some bird predecessors. The wings most probably belonged to enantiornithes , a diverse group of avian dinosaurs. A large phylogenetic analysis of early dinosaurs by Matthew Baron, David B. Norman and Paul Barrett (2017) found that Theropoda
4872-427: The identification of species in forensic studies, particularly in bird strikes to aircraft. The ratios of hydrogen isotopes in feathers help in determining the geographic origins of birds. Feathers may also be useful in the non-destructive sampling of pollutants. The poultry industry produces a large amount of feathers as waste, which, like other forms of keratin, are slow to decompose. Feather waste has been used in
4959-470: The incidence of nestling cannibalism among some colonially nesting species, as the stiffness of the feathers make the young more difficult to swallow. Pollutants can reduce the efficiency of these functions. When oiled, for example, down feathers mat and clump together, which breaks down the bird's insulation and allows water to reach the skin. Female wildfowl use down feathers plucked from their own breasts to line their scrape nests . This process performs
5046-483: The nest and provide insulation to the eggs and young. The individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads. Although feathers are light, a bird's plumage weighs two or three times more than its skeleton, since many bones are hollow and contain air sacs. Color patterns serve as camouflage against predators for birds in their habitats, and serve as camouflage for predators looking for
5133-582: The nest. The height study found that birds that nest in the canopies of trees often have many more predator attacks due to the brighter color of feathers that the female displays. Another influence of evolution that could play a part in why feathers of birds are so colorful and display so many patterns could be due to that birds developed their bright colors from the vegetation and flowers that thrive around them. Birds develop their bright colors from living around certain colors. Most bird species often blend into their environment, due to some degree of camouflage, so if
5220-480: The nests of eider ducks as early as 1890. Eiders are still "farmed" by people in Iceland, Scandinavia and Siberia. The birds are provided with nest sites and protected from predators, and down is collected intermittently during the nesting season without harming the nests or female ducks. The first collection is made roughly halfway through the incubation period, when some 0.75 oz (21 g) of high quality down
5307-621: The nests of other species also have host-specific feather lice and these seem to be transmitted only after the young cuckoos leave the host nest. Birds maintain their feather condition by preening and bathing in water or dust . It has been suggested that a peculiar behavior of birds, anting , in which ants are introduced into the plumage, helps to reduce parasites, but no supporting evidence has been found. Bird feathers have long been used for fletching arrows . Colorful feathers such as those belonging to pheasants have been used to decorate fishing lures . Feathers are also valuable in aiding
SECTION 60
#17327689979785394-462: The original primary function as the feathers simply would not have been capable of providing any form of lift. There have been suggestions that feathers may have had their original function in thermoregulation, waterproofing, or even as sinks for metabolic wastes such as sulphur. Recent discoveries are argued to support a thermoregulatory function, at least in smaller dinosaurs. Some researchers even argue that thermoregulation arose from bristles on
5481-463: The parasite species being specific to the host and coevolving with the host, making them of interest in phylogenetic studies. Feather holes are chewing traces of lice (most probably Brueelia spp. lice) on the wing and tail feathers. They were described on barn swallows , and because of easy countability, many evolutionary, ecological, and behavioral publications use them to quantify the intensity of infestation. Parasitic cuckoos which grow up in
5568-492: The past to dress some of the miniature birds featured in singing bird boxes . This trade caused severe losses to bird populations (for example, egrets and whooping cranes ). Conservationists led a major campaign against the use of feathers in hats. This contributed to passage of the Lacey Act in 1900, and to changes in fashion. The ornamental feather market then largely collapsed. More recently, rooster plumage has become
5655-432: The prime caregivers, evolution has helped select females to display duller colors down so that they may blend into the nesting environment. The position of the nest and whether it has a greater chance of being under predation has exerted constraints on female birds' plumage. A species of bird that nests on the ground, rather than the canopy of the trees, will need to have much duller colors in order not to attract attention to
5742-466: The rachis and herringbone pattern of the barbs. In the clade Deinonychosauria, the continued divergence of feathers is also apparent in the families Troodontidae and Dromaeosauridae . Branched feathers with rachis, barbs, and barbules were discovered in many members including Sinornithosaurus millenii , a dromaeosaurid found in the Yixian formation (124.6 MYA). Previously, a temporal paradox existed in
5829-654: The recent common ancestors of birds, Oviraptorosauria and Deinonychosauria . In 1998, the discovery of a feathered oviraptorosaurian, Caudipteryx zoui , challenged the notion of feathers as a structure exclusive to Avialae. Buried in the Yixian Formation in Liaoning, China, C. zoui lived during the Early Cretaceous Period. Present on the forelimbs and tails, their integumentary structure has been accepted as pennaceous vaned feathers based on
5916-417: The reptiles. Anglers who fly fish have long used the down feathers of waterfowl for the construction of fishing lures . Because they are white, down feathers can be easily dyed a variety of colours. They are used to make the bodies, tails and wing casings of the flies. Historically, much of the down used for the flies came from the wing and tail of the marabou stork ; these feathers were also popular with
6003-412: The rictal bristles. Grebes are peculiar in their habit of ingesting their own feathers and feeding them to their young. Observations on their diet of fish and the frequency of feather eating suggest that ingesting feathers, particularly down from their flanks, aids in forming easily ejectable pellets. Contour feathers are not uniformly distributed on the skin of the bird except in some groups such as
6090-413: The same species, than those unpigmented or with carotenoid pigments. However, another study the same year compared the action of bacteria on pigmentations of two song sparrow species and observed that the darker pigmented feathers were more resistant; the authors cited other research also published in 2004 that stated increased melanin provided greater resistance. They observed that the greater resistance of
6177-485: The same weight. Insulation in most outdoor equipment ranges from about 400 to 900 in /oz (230–520 cm /g). Down rated 500–650 in /oz (290–380 cm /g) is warm enough and light enough for most conditions, and 800–900 in /oz (460–520 cm /g) fill is used for very lightweight and/or very cold-weather gear. Down is warm, lightweight and packable. If well cared for, it retains its loft up to three times longer than do most synthetics. However, when it
6264-433: The scale-feather converters Sox2 , Zic1 , Grem1 , Spry2 , and Sox18 . Feathers and scales are made up of two distinct forms of keratin , and it was long thought that each type of keratin was exclusive to each skin structure (feathers and scales). However, feather keratin is also present in the early stages of development of American alligator scales. This type of keratin, previously thought to be specific to feathers,
6351-399: The sequence in which feathers first evolved and developed into the types found on modern birds. Feather evolution was broken down into the following stages by Xu and Guo in 2009: Down feather The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in
6438-414: The sheath not splitting as it should during the final stages of the feather's growth. Because of that abnormal splitting, the bird's down appears to be matted; chicks with this condition look bristly and singed and tend to be lighter in body weight than normal chicks are. Down feathers are used by Indigenous North Americans for religious ceremonies and as powerful symbols. In the stories of some cultures,
6525-453: The sole exception; they are already covered with contour feathers when they hatch. Body down is a layer of small, fluffy feathers that lie underneath the outer contour feathers on a bird's body. Powder down, or pulviplumes, is a special type of down that occurs in a few groups of apparently unrelated birds. In some species, the tips of the barbules on powder down feathers disintegrate, forming fine particles of keratin , which appear as
6612-535: The species habitat is full of colors and patterns, the species would eventually evolve to blend in to avoid being eaten. Birds' feathers show a large range of colors, even exceeding the variety of many plants, leaf, and flower colors. The feather surface is the home for some ectoparasites, notably feather lice ( Phthiraptera ) and feather mites. Feather lice typically live on a single host and can move only from parents to chicks, between mating birds, and, occasionally, by phoresy . This life history has resulted in most of
6699-467: The subfamily of feather β-keratins found in extant birds started to diverge 143 million years ago, suggesting the pennaceous feathers of Anchiornis were not made of the feather β-keratins present in extant birds. However, a study of fossil feathers from the dinosaur Sinosauropteryx and other fossils revealed traces of beta-sheet proteins, using infrared spectroscopy and sulfur-X-ray spectroscopy. The presence of abundant alpha-proteins in some fossil feathers
6786-412: The ulna of some birds, they consider it more likely that these are attachments for interosseous ligaments. This was refuted by Cuesta Fidalgo and her colleagues, they pointed out that these bumps on the ulna are posterolateral which is unlike that of interosseous ligaments. Since the 1990s, dozens of feathered dinosaurs have been discovered in the clade Maniraptora , which includes the clade Avialae and
6873-497: The ultraviolet region, but studies have failed to find evidence. The oil secretion from the uropygial gland may also have an inhibitory effect on feather bacteria. The reds, orange and yellow colors of many feathers are caused by various carotenoids. Carotenoid-based pigments might be honest signals of fitness because they are derived from special diets and hence might be difficult to obtain, and/or because carotenoids are required for immune function and hence sexual displays come at
6960-438: The vaned feathers. The pennaceous feathers are vaned feathers. Also called contour feathers, pennaceous feathers arise from tracts and cover the entire body. A third rarer type of feather, the filoplume , is hairlike and are closely associated with pennaceous feathers and are often entirely hidden by them, with one or two filoplumes attached and sprouting from near the same point of the skin as each pennaceous feather, at least on
7047-422: The visible range. The wing feathers of male club-winged manakins Machaeropterus deliciosus have special structures that are used to produce sounds by stridulation . Some birds have a supply of powder down feathers that grow continuously, with small particles regularly breaking off from the ends of the barbules. These particles produce a powder that sifts through the feathers on the bird's body and acts as
7134-480: The webbing; however, that developmental process involves a tubular structure arising from a follicle and the tube splitting longitudinally to form the webbing. The number of feathers per unit area of skin is higher in smaller birds than in larger birds, and this trend points to their important role in thermal insulation, since smaller birds lose more heat due to the relatively larger surface area in proportion to their body weight. The miniaturization of birds also played
7221-675: The word pen itself is derived from the Latin penna , meaning feather. The French word plume can mean feather , quill , or pen . Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis , or outer skin layer, that produce keratin proteins . The β-keratins in feathers, beaks and claws – and the claws, scales and shells of reptiles – are composed of protein strands hydrogen-bonded into β-pleated sheets , which are then further twisted and crosslinked by disulfide bridges into structures even tougher than
7308-418: The world's supply comes from China, typically from birds killed for their meat. Most of the rest comes from Europe and Canada, from birds harvested for meat or pâté . A portion of the world's supply of down feathers are plucked from live birds, a practice condemned as cruel by animal welfare groups. The precise percentage of down harvested in this manner is uncertain; while some references report that it
7395-490: The yellow to red psittacofulvins (found in some parrots ) and the red turacin and green turacoverdin ( porphyrin pigments found only in turacos ). Structural coloration is involved in the production of blue colors, iridescence , most ultraviolet reflectance and in the enhancement of pigmentary colors. Structural iridescence has been reported in fossil feathers dating back 40 million years. White feathers lack pigment and scatter light diffusely; albinism in birds
7482-512: Was by assuming that primitive pterosaurs were scaly. A 2016 study analyzes the pulp morphology of the tail bristles of Psittacosaurus and finds they are similar to feathers but notes that they are also similar to the bristles on the head of the Congo peafowl , the beard of the turkey , and the spine on the head of the horned screamer . A reestimation of maximum likelihoods by paleontologist Thomas Holtz finds that filaments were more likely to be
7569-674: Was shown to be an artefact of the fossilization process, as beta-protein structures are readily altered to alpha-helices during thermal degradation. In 2019, scientists found that genes for the production of feathers evolved at the base of archosauria, supporting that feathers were present at early ornithodirans and is consistent with the fossil record. Several non-avian dinosaurs had feathers on their limbs that would not have functioned for flight. One theory suggests that feathers originally evolved on dinosaurs due to their insulation properties; then, small dinosaur species which grew longer feathers may have found them helpful in gliding, leading to
#977022