Dictionary:

beak

  (bēk)

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beak

top to bottom: black skimmer, male pileated woodpecker, and male American goldfinch (Elizabeth Morales)

1. 1. The horny, projecting structure forming the mandibles of a bird, especially one that is strong, sharp, and useful in striking and tearing; a bill.
   2. A similar structure in other animals, such as turtles, insects, or fish.
2. A usually firm, tapering tip on certain plant structures, such as some seeds and fruits.
3. A beaklike structure or part, as:
   1. The spout of a pitcher.
   2. A metal or metal-clad ram projecting from the bow of an ancient warship.
4. Informal. The human nose.
5. Chiefly British Slang.
   1. A schoolmaster.
   2. A judge.

[Middle English bek, from Old French bec, from Latin beccus, of Celtic origin.]

noun

1. The horny projection forming a bird's jaws: bill. See mouth.
2. The structure on the human face that contains the nostrils and organs of smell and forms the beginning of the respiratory tract: nose, proboscis. Informal snoot. Slang nozzle, schnoz, schnozzle, snout. See body/spirit, convex/concave.

For more information on beak, visit Britannica.com.

The hard keratinization (or rhamphotheca) which provides the horny covering of the beak bones, plus the beak bones, of birds. The dorsal ridge of the upper beak is the culmen, the similar keel of the lower beak is the gonys. The cutting edges of the beak are the tomia. Called also bill.

Different shape of beak between species. By permission from Aspinall V, O'Reilly M, Introduction to Veterinary Anatomy and Physiology, Butterworth Heinemann, 2004

• b. avulsion — traumatic separation of the upper and lower beak at the base requires hand feeding for survival of the bird. Some attempts at devising an artificial beak have been made, but attachment is a major problem.
• b. fracture — occurs with trauma and requires immobilization, often with innovative procedures (see acrylic glue), without restricting food intake by the bird during recovery. Severe trauma may result in avulsion of upper or lower beak.
• b. necrosis — a condition of chickens and turkeys caused by excessively fine mashed feeds.
• b. overgrowth — can result from malocclusion, liver disease, lack of wear, aging, nutritional deficiency, and most commonly infestation by the mite, Cnemidocoptes pilae.
• psittacine b. and feather disease — see psittacine beak and feather disease.
• b. sign — the radiographic feature of contrast material extending through an elongated, concentrically narrowed pylorus indicative of hypertrophy of the sphincter.
• b. trimming — in most modern poultry houses the chances of cannibalism developing are so high that beak trimming is almost a necessity, especially if the birds are to be reared in full light. Light-restricted accommodation greatly reduces the prevalence of this vice. A temporary trim is done at a few days of age but a permanent trim is necessary later. Special instruments, utilizing a hot, cutting blade cautery, are used and the operation must be done by an expert or badly deformed beaks result and the birds are unable to feed properly. Alternatives to trimming include the fitting of spectacles or pick guards but these are expensive, time-consuming to put on and not feasible for birds in cages.

The bill of a scavenger—the vulture.

The bill and knob of a domesticated Chinese goose, highly exaggerated by farm selection.

Northern Gannets billing.

The bill of the Greater Flamingo

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. The term also refers to a similar mouthpart in some cephalopods and cetaceans.

A- Nectar feeding (eg: Sunbird) B- Insectivore (eg: Flycatcher) C- Granivore (eg: Grosbeak) D- Specialist seed eater (eg: Crossbill) E- Fishing (eg: Kingfisher) F- Netting (eg: Pelican) G- Filter feeding (eg: Flamingo) H- Surface probing (eg: Avocet) I- Probing (eg: Ibisbill) J- Surface skimming (eg: Skimmer) K- Raptor

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. 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. Between the hard outer layer and the bone is a vascular layer containing blood vessels and nerve endings. 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 beak has two holes called nares (nostrils) which connect to the hollow inner beak and thence to the respiratory system. 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). Hawks, parrots, doves, skuas, and budgerigars are among the birds that have ceres. Budgerigars are dimorphic in that the males' ceres turn bright blue upon maturity, while the females' ceres turn tan. 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.

Examples of birds with unusual beaks include the hummingbird, the toucan and the spoonbill.

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). 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".

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. 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

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - fuglenæb

Nederlands (Dutch)
snavel, bek, tuit, haakneus, rechter, hoofd van school

Français (French)
n. - bec, nez (crochu), (GB) juge (fam), (GB, École) protal (arch, arg)

Deutsch (German)
n. - Schnabel

Ελληνική (Greek)
n. - ράμφος, μυταρόλα, (Βρετ.) δικαστής

Italiano (Italian)
becco

Português (Portuguese)
n. - bico (m), esporão (m) de navio, colher (m), bocal (m) (Mús.)

Русский (Russian)
клюв, судья

Español (Spanish)
n. - pico, nariz ganchuda, promontorio, pitorro

Svenska (Swedish)
n. - näbb, kran, polisdomare

中文（简体） (Chinese (Simplified))
鸟嘴, 口, 喙状嘴, 鹰钩鼻, 治安法官, 治安推事

中文（繁體） (Chinese (Traditional))
n. - 鳥嘴, 口, 喙狀嘴, 鷹鉤鼻, 治安法官, 治安推事

한국어 (Korean)
n. - 부리[모양의 것], 뱃머리

日本語 (Japanese)
n. - 嘴, くち先, 口, 鼻, くちばし状のもの

العربيه (Arabic)
‏(الاسم) منقار, أنف, قاضي, حاكم, مدرس,‏

עברית (Hebrew)
n. - ‮מקור, חרטום, אף, חוטם, שופט שלום, מנהל בי"ס‬

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