The bill of a scavenger—the vulture. Vultures are scavenging Birds feeding mostly on the carcasses of dead Animals Vultures are found on every continent except Antarctica and

The bill and knob of a domesticated Chinese goose, highly exaggerated by farm selection. Domestic geese are domesticated Grey geese (either Greylag geese or Swan geese) kept as Poultry for their meat eggs and Down feathers

Northern Gannets (Morus bassanus) billing. The Northern Gannet ( Morus bassanus, formerly Sula bassana) is a Seabird and is the largest member of the Gannet family Sulidae The Northern Gannet ( Morus bassanus, formerly Sula bassana) is a Seabird and is the largest member of the Gannet family Sulidae

The bill of the Greater Flamingo, Phoenicopterus roseus. The Greater Flamingo ( Phoenicopterus roseus) is the most widespread Species of the Flamingo family

The beak of a Brown Falcon, Falco berigora. The Brown Falcon, Falco berigora, is a member of the Falcon Genus found in the drier regions of Australia

The beak of an African Penguin, Spheniscus demersus. The African Penguin ( Spheniscus demersus) also known as the Black-footed Penguin (and formerly as the Jackass Penguin) is found on the south-western coast

The beak, bill or rostrum is an external anatomical structure of birds which, in addition to eating, is used for grooming, manipulating objects, killing prey, probing for food, courtship and feeding their young. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Personal grooming (also called titivating) is the art of cleaning grooming and maintaining parts of the body Courtship is the traditional dating period before engagement and marriage The term also refers to a similar mouthpart in some cephalopods, cetaceans, pufferfishes, turtles, Anuran tadpoles and sirens. The cephalopods ( Greek plural (kephalópoda "head-feet" are the Mollusc class Cephalopoda characterized by The Order Cetacea (sɪˈteɪʃiə L cetus, whale includes Whales Dolphins and Porpoises Cetus is Tetraodontidae is a family of primarily marine and estuarine fish Turtles are Reptiles of the Order Testudines (all living turtles belong to the Crown group Chelonia) most of This article is about the block cipher algorithm For the ultrafast laser pulse measurement technique see Frequency-resolved optical gating. A tadpole or polliwog (also pollywog, polliwig, polewig, or polwig) is the wholly aquatic larval stage in the life cycle of Not to be confused with order Sirenia (manatees and dugongs The sirens are a family of Aquatic Salamanders

Comparison of different types of bird beaks, displaying the different shapes that are a result of different feeding adaptations. Bird heads are not shown to scale.

Anatomy

Beaks can vary significantly in size and shape from species to species. The beak is composed of an upper jaw called the maxilla, and a lower jaw called the mandible. This article is about the Mammal maxilla For Arthropod maxillae see Mouthparts; for Insect maxillae in particular see Insect mouthparts The mandible (from Latin mandibula, "jawbone" or inferior maxillary bone forms the lower Jaw and holds the lower teeth in place The jaw is made of bone, typically hollow or porous to conserve weight for flying. The outside surface of the beak is covered by a thin horny sheath of keratin called the rhamphotheca. Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds Between the hard outer layer and the bone is a vascular layer containing blood vessels and nerve endings. The blood vessels are part of the Circulatory system and function to transport Blood throughout the body The rhamphotheca also includes the knob which is found above the beak of some swans, such as the Mute Swan, and some domesticated Chinese geese (pictured). The Mute Swan ( Cygnus olor) is a Eurasian member of the Duck, Goose and Swan family Anatidae. Domestic geese are domesticated Grey geese (either Greylag geese or Swan geese) kept as Poultry for their meat eggs and Down feathers

The beak has two holes called nares (nostrils) which connect to the hollow inner beak and thence to the respiratory system. lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive The nares are usually located directly above the beak. In some birds, they are located in a fleshy, often waxy structure at the base of the beak called the cere (from Latin cera). Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Hawks, parrots, doves, skuas and budgerigars are among the birds that have ceres. 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 Parrots are birds of the roughly 350 Species in 85 genera comprising the order Psittaciformes, found in most warm and tropical regions Skuas are Seabirds in the family Stercorariidae. The three smaller skuas are called jaegers in North America The budgerigar ( Melopsittacus undulatus) commonly called parakeet, shell parakeet, budgie, or common pet parakeet in US English Budgerigars are dimorphic in that the males' ceres turn bright blue upon maturity, while the females' ceres turn tan. Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. The female budgies' ceres also appear wrinkled, to a greater extent during periods of fertility. Immature budgies have pale pinkish ceres which are smooth and shiny.

On some birds, the tip of the beak is hard, dead tissue used for heavy-duty tasks such as cracking nuts or killing prey. On other birds, such as ducks, the tip of the bill is sensitive and contains nerves, for locating things by touch. The beak is worn down by use, so it grows continuously throughout the bird's life.

Unlike jaws with teeth, beaks are not used for chewing. Birds swallow their food whole, which is broken up in the gizzard. The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ in the digestive tract found in Birds Reptiles

Examples of birds with unusual beaks include the hummingbird, the toucan and the spoonbill. Hummingbirds are Birds in the family Trochilidae, and are endemic to the Americas. Toucans are a family Ramphastidae, of Near-passerine Birds from the Neotropics (i "Spoonbill" could also mean Northern Shoveler or Paddlefish.

In the mallard, and perhaps in other ducks, there is no cere, and the nostrils are in the hard part of the beak, as a soft cere would be liable to injury when the duck dredges for food among submerged debris and stones. The Mallard ( Anas platyrhynchos) probably the best-known and most recognizable of all ducks is a Dabbling duck which breeds throughout the Temperate For duck as a food see Duck (food; for other meanings see Duck (disambiguation.

Billing

During courtship, mated pairs of a variety of bird species touch and clasp each other's bills. This is called billing, and appears to strengthen the pair bond (Terres, 1980). In Biology, a pair bond is the strong affinity that develops in some Species between the Male and Female in a breeding pair Gannets raise their bills high and repeatedly clatter them (pictured); the male puffin nibbles at the female's beak; the male waxwing puts his bill in the female's mouth; and ravens hold each other's beaks in a prolonged "kiss". Gannets are Seabirds in the family Sulidae, closely related to the boobies. Puffin describes any of four Auk species (or alcids) in the Bird genus Fratercula (Latin little brother — probably a reference For the Seattle band featuring Rocky Votolato, see Waxwing (band. Raven is the common name given to the largest species of Passerine Birds in the Genus Corvus.

Terminology

The term decurved refers to a downward curving beak.

See also

• Bird anatomy

References

• Gilbertson, Lance; Zoology Lab Manual; McGraw Hill Companies, New York; ISBN 0-07-237716-X (fourth edition, 1999)
• Terres, John. Bird anatomy, or the physiological structure of Birds K. The Audubon Society Encyclopedia of North American Birds, New York: Alfred A. Knopf, 1980. ISBN 0-394-46651-9

External links

• http://www.peteducation.com/article.cfm?cls=15&cat=1829&articleid=2752
• http://www.birdsnways.com/wisdom/ww53eiv.htm
• http://qp-society.com/qpserc/beak.html