Flightless bird

Flightless birds evolved in the course of evolution from airworthy precursors. There are about 40 extant flightless bird species.

Terms of flying

While the development of such a complex skill like flying, many genes must develop carefully coordinated, can already cause the absence of a gene for inability to fly.

Thus, a bird can fly, he needs both wings to fly suitable and sufficient movement coordination in the brain and sense organs, which are powerful enough to control the flight appropriate. If only one of these elements is lost, the bird is unable to fly.

Therefore, it happens a lot easier for a flyable animal loses its ability to fly, as that an animal that is unable to fly, the ability to fly acquires.

Previously attended some researchers that the ratites, which include most of the Urkiefervögel, descended from only flightless ancestors. However, according to current knowledge, they also originate from flightless ancestors.

Flightlessness usually arises from the fact that the development of the wing stops on a young animals or even for animals that are still in the egg, typical state. Frequently connected in areas other than the plumage coloration and with the retention of juvenile characteristics ( neoteny ). 4 5 6 7

Flightless birds on the mainland

On the mainland, there are few flightless birds such as ostriches, rheas and cassowaries. This is because there the ability to fly offers significant advantages in the escape from predators and therefore only birds that are too big to fly, lose their ability to fly. The largest flying birds ( eg great bustard, the Andean Condor) have a weight of about 15-16 kg.

Birds that have the ability to fly abandoned in favor of better swimming or diving

In the sea there are flightless penguins and formerly the Great Auk, and three species of steamer ducks ( Tachyeres ) that use their wings as flippers and therefore unable to fly. The long wing steamer duck and various other auks use their wings as flippers likewise, they have not so far receded that they can no longer fly.

Although grebes do not use their wings as flippers, but these are relatively heavy in proportion to their size, as their bones contain air chambers. This helps them to dive for food, but it makes them harder to fly up from the water. Three species are flightless: the Titicacataucher, the Atitlántaucher ( extinct) and the Punataucher.

Fossil flungunfähige diving birds are the Hesperornithiformes.

Island birds

On islands lack the large ground-dwelling predators ( True predators), as they usually do not, the island offers enough space for a permanent population and they could not migrate to such a great distance over water.

For flying birds of prey offers flying not be as good of protection as the immersion in water or hiding in the bushes. Therefore, very small birds have few natural enemies and a population of birds such island is usually so large that only a few young animals grow up, because they are starving because of competition for food by birds amongst themselves before. One advantage of the inability to fly is that the birds can save energy to build up the flight muscles and for flying itself and therefore when malnutrition rather überleben.8 9

For the same reason island birds invest their energy in few large eggs rather than in many small eggs. Thus have the young birds from birth to a certain advantage over the offspring from larger opportunity with smaller eggs. If the parents have to worry about not so young, they can offer each of the animals more food, so they do not starve and grow faster. Since there are few predators, no large reproduction rates are necessary to ensure a sufficient portion of the pups survived to replace annually by robbers caught or died of old age and accidents adult animals. 3 6 10 11 12 13 14 15

The ancestors of the flightless birds have flown to the islands. If a style but is once flightless, they can not emigrate to another island, which is far away. Nevertheless, there are in principle to be filled on each island the same ecological niches and are caused by parallel evolution always very similar flightless bird species. Because of this similarity, it has long been believed that island birds would be more closely related to each other than with their airworthy relatives whose bone structure is extremely different. In fact, the closest relative of a flightless species is usually capable of flight. Exceptions occur almost exclusively in species that live on adjacent islands that were connected in each of the last ice age, because at that time the sea level was 100 -150m lower than today. 1 16

Before the first people entered the islands, each Polynesian island had at least two types of flightless birds. After their home islands by Polynesians or Europeans were settled, many of them have become extinct. Reasons for this are hunting, introduced predators (dogs, rats, cats) and habitat destruction. For hunting and predators, the flightless species are particularly vulnerable because of their inability to fly, their often large tameness and their low reproductive rates. 17 18

List of birds that have lost free of land predators islands their flying

Urkiefervögel:

Neukiefervögel:

• Rail Birds: Südinseltakahe ( Porphyrio hochstetteri ) Nordinseltakahe ( Porphyrio mantelli ), Lord Howe Purple Gallinule ( Porphyrio albus), Wekaralle ( Gallirallus australis), Woodhen ( Gallirallus sylvestris), fur Rail ( Gallirallus lafresnayanus ), Kosrae Crake ( Porzana Monasa ) Saint Helena Crake ( Porzana astrictocarpus ), Laysan Rail ( Porzana palmeri ), Hawaii Rail ( Porzana sandwichensis ), Tasmanian cesspool chicken ( Gallinula mortierii ), Mauritius - Rail ( Aphanapteryx bonasia ), Atlantis Rail ( Atlantisia rogersi ), St. Helena - Rail ( Aphanocrex Podarces ) Leguats Crake ( Aphanapteryx leguati ) Guamralle ( Rallus owstoni ), Wake - Rail ( Gallirallus wakensis ) Tuamotusumpfhuhn ( Porzana atra), Rotschnabelralle ( Gallirallus pacificus ) Fiji Rail ( Nesoclopeus poecilopterus ), Samoa Forest Rail ( Gallinula pacifica ), Macquarie - banded Rail ( Gallirallus philippensis macquariensis ) Nesotrochis debooyi
• Other: Moa Nalos ( Thambetochini ), Flightless Cormorant (Phalacrocorax harrisi ), Kagu ( Rhynochetos jubatus ), dodo ( Raphus cucullatus ), Rodrigues Solitaire ( Pezophaps solitaria ), Marquesen Ground Dove ( Gallicolumba rubescens ) Kakapo ( Strigops habroptilus ), Mauritius Parrot ( Lophopsittacus mauritianus ), Stephen panties ( Xenicus lyalli ) Sylviornis neocaledoniae, Apteribis

Flightless Birds House

There are some home bird breeds that are flightless. A common reason for this is Seidenfiedrigkeit that occurs in wild flightless birds such as the kiwi and the welfare of the animals otherwise not further harm. A seidenfiedrige house bird race, for example, the silkie. Further examples of the inability to fly from domestic birds are the Featherduster among the budgies and the " floor roller " at the house pigeons, which Struppfiedrigkeit in the domestic fowl and the combination of spring bonnet and feather rosette at the Japanese Mövchen. Some of the causative mutations are considered spoiled breed.