The animal class of the birds treats birds of these articles. For further meanings see the birds.
Schwarzbrauenalbatros (Thalassarche melanophris)
Schwarzbrauenalbatros (Thalassarche melanophris)
Over trunk: New mouths (Deuterostomia)
trunk: Choir-date (choir DATA)
Unterstamm: Vertebrate animals (Vertebrata)
over class: Kiefermäuler (Gnathostomata)
row: Land vertebrate animals (Tetrapoda)
class: Birds (Aves)

the birds (Aves) (of old high German: fogal too: fly) form beside the amphibians (Amphibia), reptiles (Reptilia) and mammals (Mammalia) a class of land vertebrate animals (Tetrapoda). The science of the birds is those bird customer (Ornithologie). The birds reviveall continents; so far approximately 9,800 kinds of bird are well-known. Whether this number agrees already large with the number of all today living kinds of bird, is however disputed: some Ornithologen is the view that the actual kind number could lie far over it.

Derived from advice (lat.: Bird)the adjective is aviär for: to birds referred, coming from birds.

Table of contents

general characteristics

  • The plumage determines the outside overall view of the birds substantially: The body is covered of feathers/springs. These structures from Keratin serve with flies as bearing area and control surface, an aerodynamically favorable lining of theBody and as isolation, which is changeable even, usually depending upon temperature and wind. Furthermore the plumage has colors and often serves the sexual advertisement. With water birds it is waterproof and provides for lift. The plumage is changed at certain times (Mauser).The moreover the legs are covered by Hautschuppen with all birds, which reminds of its masterhistorical development from the group of the reptiles.
  • All today living birds possess a bill without genuine teeth. There are however become extinct kinds, which were bezahnt. The bill existsall birds from horn. Exceptions form only the pigeon birds (Columbiformes) and the goose birds (Anseriformes), with which the bill consists of bone mass and is covered by a soft skin.
  • All well-known kinds of bird possess a constant Körpertemperatur (Endothermie, Homoiothermie), which is higher thanall other today living animals and approx. 42 °C amounts to.
  • Most birds are airworthy. Flight-unable kinds developed from kinds, which could originally fly. This concerns for example run birds and penguins and many island forms.
  • The bird skeleton is built easily, it possesses for weight reductionhollow bones. The portion of the bone mass constitutes only 8 to 9% of the total mass, while it can amount to with some mammals up to 30%. The very large breastbone has a protruding keel, which serves very large flight muscles as beginning for.
  • ThoseHeart flapping mode frequency is high: The maximum heart flapping mode frequency bunch finally amounts to 178 impacts per minute, that of a Haussperlings 900 and that of a Blaukehlkolibris of 1,260 impacts per minute.
  • The being correct formation takes placeBirds not in the larynx, since vocal cords are missing. But a separate organ, the being correct head (Syrinx) is, also as lower larynx “designation because of the forking of the trachea.
  • Most kinds of birdpossesses to the plumage care a special, fat separating gland, the Bürzeldrüse. With some kinds their function is supported by so-called propellant dunes and/or. completely replaces (Kakadus, pigeon birds, herons). To some kinds both Bürzeldrüse and propellant dunes (Kormorane, queue neck birds) are missing.
  • Are from the characteristics specified above only the feathers/springsto find however with the birds - in such a way (or existed) flying animals exist also with the mammals (bats) and reptiles (Flugsaurier), eggs are put also by reptiles and Amphibians and even the bill form did not remain limited to the birds.
 Archaeopteryx Lebendrekonstruktion (Spindler 2005)
Archaeopteryx living person reconstruction (Spindler 2005)

history of the development (evolution)

the birds developed in the waiters trias and/or. Law. Up to the today's day is the controversy between the trailers of tree Springer and/or. Soil runner hypothesis did not decide. The ancestors of the birds were in opinion of the majority of the researcherssmall robbery dinosaurs (Theropoden), which were after past fossil finds soil runners. The representatives of the minority position point out that there would be no flying or sliding organisms after today's knowledge those from tree-living ancestors does not descend. Since small tree-living robbery dinosaurs are unknown so far, those would have themselvesDevelops birds from lizard-like ancestors (Feduccia et al.).

The most well-known link between reptiles and today's birds is the Archaeopteryx. It possessed the today's birds similar wings. Fossils of this kind were found in the Solnhofener disk limes ( upper law). It is after its feathers/springsdesignated:Archaeopteryx means ancient feather/spring and/or Urflügel.

The sales history of the individual fossil copies, the description of find and designation reflect the fights between creationists and trailers of the biological evolution again: Archaeopteryx shows characteristics of reptiles and birds, a unbefiedertes skeleton with bad preservation can be easily falsedetermined,which with the so-called Harlemer copy the case was for many years. Whether Archaeopteryx moves forward as more direct the birds is applicable, is not clear. Many mean that it is to be arranged on a blindly ending branch of the family tree.

The kinds from that law had still Kiefer with teeth,a long tail spinal column and mobile, bekrallte Mittelhandknochen. Probably it - like some Sauropoden - was already warm bloody. Also from the later chalk - formation of received water birds were bezahnt. The today's groups of birds with their unbezahnten Kiefern developed since beginning of the Tertiary period.

as the birds came phylogenetisch to their feathers/springs?

in the People's Republic of China discovered Urvögel from the Unterkreide were similar to 1995 concerning claw hand , belly ribs and building of basins the Archaeopteryx. But some petrifying feathers/springs and a strong breastbone showed like today's birds, furthermore a billwithout teeth and schwanzwärts only a short spinal column. As one 1998 a pinnated Minisaurier (Caudipteryx) found, was the development of the birds, its feathers/springs and partly also the bird flight nearly clarified.

Therefore the bird ancestors developed first both at the front andat the Hinterextremitäten feathers/springs, obviously to the gliding flight from tree to Type. The wing formations at the Hinterextremitäten were reduced in the course of the evolution, so that only the arm - and hand rockers to flies remained.

After another thesis the feathers/springs formed first to the protection from calorific losswith soil-living, two-legged Sauriern. Also today's birds have thousands of relatively simply built Flaumfedern, but only about 50 rocker feathers/springs. A development from isolating Flaum to more complex flight feathers/springs makes also the intermediate stages of the development more plausible, which were still unsuitable for flies.

The birds unfoldedfinally in the chalk time to large diversity of species, suffered however at their end - like other groups of organisms - a large loss of their kinds and Taxa. At the beginning few survivors kinds a multiplicity of new groups of birds probably developed Tertiary period in very short time from that,those the basis our current birds are. Some these groups died. Bird fossils from the Eozän (pit Messel) occupy a various bird world, whereby the individual kinds are not only to be assigned today still living groups. An example at that time are large, carnivorous run birds, those thoseRole of the Raubtiere not developed yet took.


the oviposition is all birds a common characteristic. There are living-bearing reptiles and egg-laying mammals - for fish and Amphibians the same applies -, but no living-bearing birds. A longer carrying time would be probableand the associated weight change for the birds as fliers too unfavorably, although on the other hand bats and probably the Flugsaurier are living-bearing quite and/or. were. Perhaps the birds” did not invent “bearing living boy also completely simply.

Some birds, about run birds and goose birds havewell Kopulationsorgane developed, while other groups of birds possess no or a simply built Penis. With female birds generally only is in, the left ovary (Ovar) developed, during with the males two gonads (testicles) are present.

The follicle or Eisprung - the releasethe Eizelle - can be released by different attractions (like for example sight of a sex partner). In the opening of the Eileiters the egg remains some minutes and by sperm cells (sperm cellses), along-moved in the Eileiter, is fertilized. Afterwards muscle movements of the Eileiters carry the still incomplete egg towardthat genital aperture. In the Eileiter become the Dotter (consisting of a third proteins and two thirds fats and fat-similar materials as well as Vitaminen and mineral salts) and that already furchenden themselves Keimling only the Eiklar (protein: Proteins, salts and water), which Eihaut and finally the Eischale angelagert. InThe bowls of bird eggs calcified to contrast to the soft-shelled eggs of the reptiles strongly (up to 94 per cent lime content); they permit however a gas exchange to the respiration. By the muscle movements of the Eileiters (whose last part one calls Uterus) bird eggs receive their kind-typical form.

Bird eggscontain all nutrients, Vitamine and trace elements, which the embryo needs to its development. The oxygen essential to the metabolism is through taken up by the firm bowl. The eggs of Nestflüchtern contain more Dotter as eggs of equal large, than nest stools slipping kinds of bird. Into a caseif the Küken is already briefly after slipping to a large extent independently, during nest stools completely helplessly, unbefiedert and usually blindly from the egg creep and by parents to be for a long time fed.

Many birds breed only one egg, while the largest clutches of eggs with 20 to 22 eggsSeem to chicken birds. With some kinds also two or several females put their eggs into a common nest. Many kinds of bird pull up several yearly broods one behind the other in one reproduction period.

brood and slips of the boys

some kinds of bird (large foot chickens) use foreign warmth to the Ausbrüten of their eggs. Thosemost birds however warm their eggs in the chest and belly plumage. With some kinds the sexes taken part in the brood have breeding marks (springless skin portions at chest and belly), at which the body warmth can arrive better at the eggs than by the isolating plumage. With many kindsbreed both partners, with others only the female or more rarely excluding the male, for example the Kaiserpinguin. The breeding temperature is with approximately 34 °C. The eggs are frequently turned during the brood, in order to ensure so an even heating up. Many other factors, like sufficient humidity,no excessive heating up by sun exposure, no or only few weak vibrations and. A. are important for a successful brood. The shortest breeding duration amounts to 11 days, the longest about 12 weeks.

Briefly before slipping the eggshell became by lime dismantling of the embryo thinner. The young birdsoften already give before leaving the egg calls of itself, which often serve the synchronisation of the slipping procedure or for the relationship between old bird and Nestling are of crucial importance. The young bird reams and pickt the Eischale from the inside ago, until a small hole develops.In addition a small, hard peak on the point of the upper bill and with some kinds of bird on the lower bill part, which Eizahn trained, is, which drops or is regressed few days after slipping. The entire slipping procedure takes - depending upon kind of bird - some minutes or toto four days (tube noses).

flight-unable birds

the airworthyness is with some kinds of bird and/or. - groups secondarily missing, i.e., them are flight unable. That can have several reasons:

  • Adjustment to the life in the water, as this with the penguins that living in the Southern HemisphereCase is. Also the alkene birds living in the Northern Hemisphere show a tendency towards the flight inability, the become extinct giant alkene were flight unable. Both groups „fly “under water with their wings.
  • Digesting of low-power food requires a large and thus heavy digesting system. Grass-corrosive birds such as geese are thereforeparticularly heavily. Due to the Flugvermögens birds can increase not at will in size. Therefore there are likewise secondarily flight-unable kinds among appropriate food specialists as for example the Kakapo.
  • Also the conversion to fast running as with the African bunch can lead to flight inability.
  • As the latter can alsothe nonexistence of soil-inhabiting robbery mammals an airworthyness make redundant. Therefore many inhabitants of isolated islands gave flies up in favor of other abilities. Many kinds this became however the calamity, after by sailors nevertheless robbery mammals (e.g. Cats), rats, pigs etc. were introduced. Examples of it are those in the meantimebecome extinct Dronten (Didus ineptus) on Mauritius, the neukaledonische Kagu (Rhynochetos jubatus), the Takahé of New Zealand (Porphyrio mantelli) and the likewise flight-unable Galapagoskormoran (Nannopterum harrisi).

senses of the birds

the sense achievements of the birds do not differ fundamentallyof the mammals. However there are differences in the construction and the weighting of the individual senses, which make it often heavy to introduce itself due to the other way of life how birds notice their environment.

Haussperling (Passer domesticus)
Haussperling (Passer domesticus)


depending upon ecology to possessBird eyes numerous special adjustments. Thus owls can see more at night as day birds or humans, their seeing are however less aligned to visual acuity, than to luminous efficiency. This functions itself due to same physics as however with fast lenses, which likewise get along with little light, therebySharpness problems, particularly with the sharpness depth in-act. Moving falcons are optimized against it on day hunt, them can small objects such as booty birds over distances of over a kilometer constitute and pursue. At least small birds are able to see UV light with large birds become that UV light of the glass bodythe eye too strongly filtered. Many kinds do not only possess three color receptors like humans, but an additional color receptor for violet light at some groups of birds to a UV receptor (around 375 nanometers) developed. Evolutiv is only for this the mutation of 3 amino acids of the Opsins necessarily.

The use UV light is very different:

  • Mouse urine shines within the UV range, mouse-racing seizes can in such a way from above a landscape on its mouse wealth judge.
  • With fruits the Reifegrad can be judged completely differently, some mold fungi possesses within the UV range other colors and falls so betterup.
  • There are some kinds of bird, with which the sexes do not differ in the visible light for us, probably however in UV light. Stars or individual Meisenarten (Blaumeisen) are of it an example.

Most kinds of bird can differentiate more pictures per second than we humans (see Flicker fusion frequency). In the bird attitude therefore neon tubes are not operated with 50 Hertz, since this light for birds flickers. Bird eyes are fixed, thus immovable differently than firmly with mammals in the skull cap. Depending upon ecological adjustment the ability is for spatial seeing from kind toKind very differently. At groups of kinds, which are at a high pursuit pressure by Raubtiere (z. B. Deaf ones and chicken birds), are laterally arranged at the head the eyes. This permits a nearly complete panorama around 360°, the lap of the fields of view and thus the ability for spatial seeing is but relatively small. Owls represent the other extreme. With them the eyes are next to each other arranged at the front of the head (thus as with humans). The fields of view of the eyes overlap very strongly, accordingly well are therefore also spatial vision. The small lateral expansion of theField of view becomes balanced by a very strong mobility of the neck spinal column. Owls can turn their head over up to 270°.

Many birds whip when going with the head forwards and back. The backward motion serves for it, the head for one moment relative to the environment in peaceto hold, so that the picture on the retina does not move, in favor of the better recognizability of moved objects - as for example a Raubtieres.

sense of magnet

with some kinds, particularly with migratory birds, is proven a sense for the magnetic field of the earth. This sense of magnet is probably in the right eye of the bird and/or in the bill locates.

The sense of magnet in the eye functions with the help of the radical generation of pairs in such a way specified. Here the light falling in the eye lets determined molecules disintegrate to radicals. This reaction could be affected by the earth's magnetic field. The sense of magnet in the billfunctioned by stored magnetic particles, which align themselves after the magnetic field of the earth and exercise so an attraction to the surrounding nerve tissue. Contrary to the technical compass the sense of magnet of the birds depends not on the polarity of the magnetic field, but be based on the recognitionthe inclination of the earth's magnetic field lines.

Experimentally the sense of magnet was proven for the first time to 1967 at zoo-logical Institut in Frankfurt/Main by Wolfgang Wiltschko with robins.


birds to possess no cap, which is outside hearing opening surrounded by a wreath/ring of small feathers/springs. For sound locating must Birds therefore intensive head movements implement. The tympanic cavity possesses only one auditory ossicle, the Columella, which corresponds to the stirrup of the mammals. The snail is relatively short and only easily wound and as Papilla basilaris is designated. The sense of hearing is nevertheless relatively well developed with birdsand for example great importance for the booty hunt has with owls. The frequency range is similarly as with humans, deep tones to 100 Hertz is not noticed. The temporal resolving power for tones lies over that of humans. Ornithologen must make do with many sound expressions of birds with it,the fact that they take up it and slowed down plays, in order to be able to hear the details.


independent organs of equilibrium possess sense of balance of birds. Beside an organ of equilibrium in the ear a second organ sits in the basin, which analyzes the body situation for example when sitting on branches. Birds,with those this organ is destroyed, can without sense of face to disturbances as for example the rotation of the seat branch to be reacted no longer correctly.

sense of smell

very long time one proceeded from the conception that birds possess only a small developed sense of smell (so-called. Mikrosmatiker).As exception was considered the Kiwi of New Zealand, which its nose opening at the bill point has and predominantly after the smell oriented. In addition, the group of the American new world vultures possesses as can be prove smell abilities. That becomes among other things attributed to the missing nasal septum and is in open land observations and - tryproven. Newer investigations show however that also different kinds of bird have at least humans equal smell feeling.

are appropriate

for sense of taste the taste buds of the birds not as with the mammal on the tongue, but in the range of the tongue reason and in the throat. The amount of thatTaste buds is clearly smaller than with mammals (duck about 200, humans 9,000), yet is the sense of taste with birds not as subordinated as one for a long time assumed. Depending upon kind the taste plays in relation to the Tastsinn of the bill and the tongue however with the food selectiona subordinated role.

Kopf- und Schnabelform
Head and bill form
Darmkanal und Fußformen
intestine channel and foot forms

orders and families of the birds

the class of the birds is the species-richest of the land vertebrate animals. It covers about 9,000 kinds of bird with approx. 35,000 subspecies. Of their two subclasses (Urkiefer and Neukiefervögel)first became extinct small and with the exception of 6 families. This way belong in particular the run birds, which are flight unable because of the missing breastbone comb. From the further about 30 orders that one of the sparrow birds covers nearly 60 per cent of all kinds. In this group again the subordination is that Singing birds (Passeri) the most extensive. A systematic overview is under systematics of the birds.

bird protection

the number of the kinds of bird decreases. Many of the become extinct kinds belonged to island populations; they were exterminated by humans or by him introduced other animal species. At present applyover 10 per cent of the 9,000 rezenten kinds of bird as endangers. They are specified in so-called red lists. World-wide the bird protection organization BirdLife international works, with its national in each case partner organizations for the protection of the birds and its habitats. In Germany the nature protection federation is Germany (NABU, the national federation forBird protection LBV in Bavaria is attached) the national partner of BirdLife. In Switzerland Swiss bird protection of sports association , ASPO, ASPU work and in Austria Birdlife Austria for the receipt of the diversity of species as BirdLife partners.

See also: Bird control room, Sibley Ahlquist taxonomy, systematics of the birds, become extinct birds

the Homo

observed birds and humans since the people becoming sapiens also the birds attentively, in order from them to orient themselves or warn let to hunt or catch it. The African honey indicator for example leads humans to the nests of game bees, overto eat the larvae, while humans profit from the honey. Quite many kinds of bird play therefore in the mythology a role, from the eagle to the sparrow. Birds appear into many phrases: Someone stinks like a Wiedehopf or is zänkisch like a Meise or is simplea Gimpel, if it goes to everyone on the glue (meant here the bird glue). Gestisch can show one it a bird. In the arts numerous kinds of bird emerge, in order to call only the marvelous journey of the small Nile Holgersson with the game geese.

Inmany culture areas are mythologische birds to be found. Mentioned for instance if Phönix are, seize, Ziz (Jewish), smelled (Arab), Feng (Chinese) or Garuda (Indonesian). Besides the Harpyien of the Greek legend world as well as Wotans companion , the Raben Hugin and Munin is mentioned.

Also the heraldryis rich at representative motives for bird. Here goes in particular the eagle into action, which is the coat of arms animal of many States of (Germany , Austria , Poland , the USA and others).

Humans hold numerous kinds of bird as house - or utilizable animals. In Germany the use of native kinds of bird takes asDomestic animal since that 19. Century however strongly off. The consumption of poultry fulfills an important role with the human nutrition, because the meat is with low fat and supplies high-quality protein. Some kinds, if already as young birds and in the cage patiently in addition continue, it also, words learnto after-award and short sentences, so particularly - arranged according to descending Gelehrigkeit - parrots and Beos, stars as well as different kinds of the Rabenvögel. They can z multiple be straightened. B. Grains of the lips to take up up to the Dressur as a utilizable animal, for example as a hunt falcon. Canary were in Germany into the 50's important utilizable animals in coal mines, where their behavior before the occurrence poisonous gases (Carbon monoxide) warned, which can withdraw with the Stollenvortieb.

Living together with birds, in particular the intensive contact, saves serious for humans however every now and thenDriven in form of transferable diseases (zoo eyes). In individual cases is for example the exciter of the poultry plague and/or. transferred to humans, the disease process ends to the bird flu usually deadly.

See also: Bird-sang

further information

Wiktionary: Bird - word origin, synonyms and translations


  • a hard Bezzel, Roland Prinzinger: Ornithologie. Publishing house Eugen Ulmer, 2. Edition, Stuttgart 1990, ISBN 3825280519

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bird voices


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