Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. Plumage refers both to the layer of Feathers that cover a Bird and the pattern colour and arrangement of those feathers Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. They are the outstanding characteristic that distinguishes the Class Aves from all other living groups. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Other Theropoda also had feathers (see Feathered dinosaurs). Theropods (ˈθɪərəpɒd theropoda /θiːˈrɒpədə/ 'beast feet' are a group of Bipedal Saurischian Dinosaurs Although they were primarily The realization that Dinosaurs are closely related to Birds raised the obvious possibility of feathered dinosaurs.

A white feather

Detail of the feathers of a young Yellow-headed Amazon. The Yellow-headed Amazon ( Amazona oratrix) also known as the Yellow-headed Parrot Double Yellow-headed Amazon, etc

Parts of a feather:
1. Vane
2. Rachis
3. Barb
4. Afterfeather
5. Hollow shaft, calamus

Characteristics

Feathers are among the most complex structural organs found in vertebrates: integumentary appendages, formed by controlled proliferation of cells in the epidermis, or outer skin layer, that produce keratin proteins. Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes The Integumentary System is an organ system that protects the body from damage comprising the Skin, Hair, scales, nails, sweat glands and their An appendage in the broadest sense is an additional or subsidiary part existing on or added to something which can generally still function if the appendage has never existed or The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Epidermis is the outermost layer of the Skin. It forms the waterproof protective wrap over the body's surface and is made up of stratified squamous Epithelium with Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl 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 the α-keratins of mammalian hair, horns and hoof. Anatomy Stegosaurus --> Beaks can vary significantly in size and shape from species to species A claw is a curved pointed appendage found at the end of a toe or finger in most Mammals, Birds, and some Reptiles. In most biological nomenclature a scale ( Greek lepid, Latin squama) is a small rigid plate that grows out of an Animal Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers A hydrogen bond results from a Dipole-dipole force between an Electronegative atom and a Hydrogen atom bonded to Nitrogen, Oxygen The β sheet (also β-pleated sheet) is the second form of regular Secondary structure in Proteins consisting of beta strands connected laterally Cross-links are bonds that link one Polymer chain to another They can be Covalent bonds or Ionic bonds "Polymer chains" can refer In Chemistry, a disulfide usually refers to the structural unit composed of a linked pair of sulfur atoms Hair is a keratinised protein filament that grows through the epidermis from follicles deep within the Dermis. A horn is a pointed projection of the Skin on the head of various Mammals consisting of a covering of horn ( Keratin and other Proteins HoofRearHoovesjpg|thumb|200px|right|Rear hooves of a horse]] A hoof is the tip of a Toe of an Ungulate Mammal, strengthened by a thick horny (

Feathers insulate birds from water and cold temperatures. The individual feathers in the wings and tail play important roles in controlling flight. These have their own identity and are not just randomly distributed. Some species have a crest of feathers on their heads. The crest is a prominent feature exhibited by several Bird and Dinosaur species 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 by predators looking for a meal. Camouflage is a method of cryptic or concealing coloration that allows an otherwise visible Organism As with fish, the top and bottom colors may be different 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 selection of mating pairs. Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. The remarkable colors and feather sizes of some species have never been fully explained.

There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath the vaned feathers. For the record label see Duck Down Records The down of Birds is a layer of fine Feathers found under the tougher exterior feathers The pennaceous feathers are vaned feathers. Pennaceous feathers are also known as contour Feathers and are present in most modern Birds and in some species of Maniraptoran Dinosaurs Also called contour feathers, pennaceous feathers are distributed over the whole body. Some of them are modified into remiges, the flight feathers of the wing, and rectrices, the flight feathers of the tail. Flight feathers are the long stiff asymmetrically shaped but symmetrically paired Feathers on the Wings or Tail of a Bird; those on the A typical vaned feather features a main shaft, called the rachis. Rachis is also the alternate spelling of Ratchis, king of the Lombards 744-749 Fused to the rachis are a series of branches, or barbs; the barbs themselves are also branched and form the barbules. Barbs are a series of branches fused to the rachis (stem of a Feather. Barbules are a part of the tree formed by Feathers: the trunk or axis being the rachis and the barbs ' the main boughs barbules are the secondary 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 much 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 a follicle in the skin. Quill is a high level object oriented Programming language created by the Dutch software company Quintiq. A hair follicle is part of the Skin that grows Hair by packing old cells together The skin is the outer covering of living tissue of an animal (or plant

Feather microstructure showing interlocking

The Dyck texture is what causes the colors blue and green in most parrots. This is due to a texture effect in microscopic portions of the feather itself, rather than pigment, or the Tyndall effect as was previously believed. The Tyndall effect is an effect of light Scattering by colloidal particles or particles in suspension. The Dyck texture alters color produced by pigment. Thus, an albino parrot will be white. The spectacular red feathers of certain parrots owe their vibrancy to a rare set of pigments found nowhere else in nature. Albinism is a rare lack of pigment in some or all of a bird's feathers. Albinism in birds is rare occurring to any extent in perhaps one in 1800 individuals (Terres 1980

In some birds, the feather colors may be created or altered by uropygial gland secretions. The yellow bill colors of many hornbills are produced by preen gland secretions. Other differences that may only be visible in the ultraviolet region are also possible. ^[1]

Two feathers

A bird's feathers are replaced periodically during its life through molting. In Biology, moulting (or molting, also known as shedding or for some species Ecdysis) signifies the manner in which an animal routinely New feathers are formed through the same follicle from which the old ones were fledged.

Some birds have a supply of powder down feathers which grow continuously, with small particles regularly breaking off from the ends of the barbules. Powder down is a special type of Down feathers They occur in a few groups of apparently unrelated birds and thus are probably Evolutionary Homoplasies. These particles produce a powder that sifts through the feathers on the bird's body and acts as a waterproofing agent and a feather conditioner. A conditioner is something that improves the quality of another material Powder down has evolved independently in several taxa and can be found in down as well as pennaceous feathers. They may be scattered in plumage 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 feathers and to spread them while cockatoos may use their head as a powder puff to apply the powder. ^[1] Waterproofing can be lost by exposure to emulsifying agents due to human pollution. An emulsion ( IPA: /ɪˈmʌlʃən/ is a mixture of two Immiscible (unblendable liquids Pollution is the introduction of contaminants into an environment that causes instability disorder harm or discomfort to the physical systems or living organisms they are in Feathers can become waterlogged and birds may sink. It is also very difficult to clean and rescue birds whose feathers have been fouled by oil spills. For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into

Bristles are stiff, tapering feathers with a large rachis but few barbs. A bristle is a stiff Hair or Feather. Also used are synthetic materials such as nylon or straw in items such as brooms and sweepers Rictal bristles are bristles found around the eyes and bill. They may serve a similar purpose to eyelashes and vibrissae in mammals. An eyelash or simply lash is one of the hairs that grow at the edge of the Eyelid. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands It has been suggested that they may aid insectivorous birds in prey capture or that it may have sensory functions, however there is no clear evidence. ^[2] In one study, Willow Flycatchers (Empidonax traillii) and they were found to catch insects equally well before and after removal of the rictal bristles. ^[3]

Feather tracts or pterylae and their naming

Feathers are not uniformly distributed on the skin of the bird except in the Penguin. Penguins ( order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless Birds living almost In most birds the feathers grow from specific tracts of skin called pterylae while there are regions which are free of feathers called apterylae. The arrangement of these feather tracts, pterylosis, varies across bird families.

Evolution

Feathers most likely originated as a filamentous insulation structure, or possibly as markers for mating, with flight emerging only as a secondary purpose. It has been thought that feathers evolved from the scales of reptiles, but recent research suggests that while there is a definite relationship between these structures, it remains uncertain of the exact process. In most biological nomenclature a scale ( Greek lepid, Latin squama) is a small rigid plate that grows out of an Animal Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers (see Quarterly Review of Biology 77:3 (September 2002): 261-95). In experiments where a virus was used to reduce the levels of certain proteins in chicken embryos, the chickens retained webbed feet, and the scutes developed into feathers. The scales, however, did not develop into feathers, and the research suggests that feathers did not evolve from reptilian scales. ^[4]

Feathered dinosaurs

Main article: Feathered dinosaurs

Several dinosaurs have been discovered with feathers on their limbs that would not have functioned for flight. The realization that Dinosaurs are closely related to Birds raised the obvious possibility of feathered dinosaurs. The realization that Dinosaurs are closely related to Birds raised the obvious possibility of feathered dinosaurs. One theory is that feathers originally developed on dinosaurs as a means of insulation; those small dinosaurs that then grew longer feathers may have found them helpful in gliding, which would have begun the evolutionary process that resulted in some proto-birds like Archaeopteryx and Microraptor zhaoianus. The term thermal insulation can refer to materials used to reduce the rate of Heat transfer, or the methods and processes used to reduce heat transfer Archaeopteryx, sometimes referred to by its German name Urvogel ("original bird" or "first bird" is the earliest and most primitive Bird Microraptor (meaning "small thief" is a Genus of small Dromaeosaurid Dinosaur. Other dinosaurs discovered with feathers include Pedopenna daohugouensis, Sinosauropteryx, and Dilong paradoxus, a tyrannosauroid which is 60 to 70 million years older than Tyrannosaurus rex. Pedopenna ("foot feather" is a Genus of small feathered Maniraptoran Dinosaur from the Daohugou Beds in China Sinosauropteryx (meaning "Chinese lizard-wing" is the first and most primitive Genus of Dinosaur found with the fossilized impressions of Dilong (which means 'emperor dragon' is a Genus of small tyrannosauroid Dinosaur. Tyrannosauroidea (meaning 'tyrant lizard forms' is a Superfamily (or Clade) of Coelurosaurian Theropod Dinosaurs that includes Tyrannosaurus ( or, meaning 'tyrant lizard' is a Genus of Theropod Dinosaur. Currently the question is not whether birds are dinosaurs, but whether they are deinonychosaurians or are dromaeosaurids. The Deinonychosauria ("fearsome claw lizards" were a successful Clade of theropods in the Late Jurassic and Cretaceous Periods Dromaeosauridae is a family of Bird -like Theropod Dinosaurs They were small to medium-sized feathered Carnivores that flourished in the It has been suggested that Pedopenna is older than Archaeopteryx, however, their age remains doubted by some experts.

Human uses

Shaft of Indian Peacock tail feather

Feathers have a number of utilitarian and cultural and religious uses.

Utilitarian functions

Feathers are both soft and excellent at trapping heat; thus, they are sometimes used in high-class bedding, especially pillows, blankets, and mattresses. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature Bedding refers to the materials laid above the mattress of a bed for warmth A pillow is a large Cushion support for the head, usually used while Sleeping in a Bed, or for the body as used on a Couch or A blanket is a type of Bedding, generally speaking a large piece of cloth intended to keep the user warm especially while Sleeping Blankets are distinguished from A mattress is a mat or pad usually placed atop a Bed, upon which to sleep or lie They are also used as filling for winter clothing, such as quilted coats and sleeping bags; goose down especially has great loft, the ability to expand from a compressed, stored state to trap large amounts of compartmentalized, insulating air. Clothing (also called clothes, accoutrements, accouterments, or habiliments) protects the Human body from extreme Weather A sleeping bag is a protective "bag" for a person to Sleep in essentially a Blanket that can be closed with a zipper or similar means and functions as Goose (plural geese) is the English name for a considerable number of Birds belonging to the family Anatidae. Bird feathers have long been used for fletching arrows and in the past were used for ink pens. Fletching is the ancient art of aerodynamically stabilizing Arrows from materials such as feathers An arrow is a pointed Projectile that is shot with a bow. It predates recorded history and is common to most Cultures. Colorful feathers such as those belonging to pheasants have been used to decorate fishing lures and hats. Pheasants are a group of large Birds in the order Galliformes. In terms of Recreational fishing, a lure is an object attached to the end of the Fishing line and designed to resemble and move like an item of Fish Prey A hat is a headcovering It may be worn for protection against the elements for religious reasons for safety or as a Fashion accessory. During the 18th, 19th, and even 20th Centuries a booming international trade in plumes, to satisfy market demand in North America and Europe for extravagant head-dresses as adornment for fashionable women, caused so much destruction (for example, to egret breeding colonies) that a major campaign against it by conservationists caused the fashion to change and the market to collapse. Headgear, headwear or headdress is the name given to any element of Clothing which is worn on one's head. This is an article about a type of bird For the EGRET satellite mission see Energetic Gamma Ray Experiment Telescope.

Feathers of large birds (most often geese) have been and are used to make quill pens. Goose (plural geese) is the English name for a considerable number of Birds belonging to the family Anatidae. Quill is a high level object oriented Programming language created by the Dutch software company Quintiq. The word pen itself is derived from the Latin penna for feather. ^[5] The French nom-de-plume for pen name has a similar origin. A pen name, nom de plume, or literary double, is a Pseudonym adopted by an Author or their publishers to conceal their identity

Cultural and religious uses

A feather from a Guinea fowl. The guineafowl (sometimes called guineahen are a family of birds in the same order as the Pheasants turkeys and other game birds and is native to

Eagle feathers have great cultural and spiritual value to American Indians in the USA and First Nations peoples in Canada as religious objects. Eagles are large birds of prey which are members of the Bird order Falconiformes and family Accipitridae, and belong to several genera Culture (from the Latin cultura stemming from colere, meaning "to cultivate" generally refers to patterns of human activity and the symbolic Spirituality, in a narrow sense concerns itself with matters of the Spirit, a concept closely tied to religious belief and Faith, a transcendent reality Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States The United States of America —commonly referred to as the First Nations is a term of Ethnicity that refers to the Aboriginal peoples in Canada who are neither Inuit nor Métis people Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page In the United States the religious use of eagle and hawk feathers are governed by the eagle feather law (50 CFR 22), a federal law limiting the possession of eagle feathers to certified and enrolled members of federally recognized Native American tribes. A religion is a set of Tenets and practices often centered upon specific Supernatural and moral claims about Reality, the Cosmos Eagles are large birds of prey which are members of the Bird order Falconiformes and family Accipitridae, and belong to several genera The term hawk can be used in several ways In strict usage in Europe and Asia, to mean any of the Species in the Subfamily In the United States, there are a number of federal wildlife laws pertaining to Eagles and their feathers (e

Various birds and their plumages serve as cultural icons throughout the world, from the hawk in ancient Egypt to the bald eagle and the turkey in the United States. In Greek mythology, Daedelus the inventor and Icarus tried to escape his prison by attaching feathered wings to his shoulders with wax, which was melted by the Sun. Greek mythology is the body of stories belonging to the ancient Greeks concerning their gods and Heroes the nature of the world and the origins and significance Icarus ( Greek:, Latin: Íkaros, Etruscan: Vicare) is a character in Greek mythology.

See also

• Flight feather
• Down feather
• Pinioning
• Eagle feather law

References

External links

• McGraw, K. J. 2005. Polly want a pigment? Cracking the chemical code to red coloration in parrots. Australian Birdkeeper Magazine 18:608-611.
• DeMeo, Antonia M. Access to Eagles and Eagle Parts: Environmental Protection v. Native American Free Exercise of Religion (1995) [2]
• Electronic Code of Federal Regulations (e-CFR), Title 50: Wildlife and Fisheries PART 22—EAGLE PERMITS [3]
• Stokes, DaShanne. (In Press) Legalized Segregation and the Denial of Religious Freedom
• U. S. v. Thirty Eight Golden Eagles (1986) [4]