Brolga crane

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Brolga crane
Brolga cranes (Grus rubicunda)

Brolga cranes ( Grus rubicunda )

Systematics
Class : Birds (aves)
Order : Crane birds (Gruiformes)
Family : Common crane (Gruidae)
Subfamily : Common cranes (Gruinae)
Genre : Grus
Type : Brolga crane
Scientific name
Grus rubicunda
( Perry , 1810)

The Brolga crane ( Grus rubicunda , Syn . : Antigone rubicunda ), also known as the Australian crane , is a bird of the family of the cranes (Gruidae). It was described scientifically for the first time in 1810 and then assigned to the genus of the heron ( Ardea ). Today he is one of the representatives of the crane birds (Gruiformes), which also include the railings and the cranes.

In 1865 the crane was given the name Australian crane by the famous ornithologist and artist John Gould , which was changed to " Brolga " in 1926 by the Royal Australasian Ornithologists Union . This name comes from one of the Aboriginal languages. The brolga crane is a common bird of tropical Eastern Australia, known for its expressive courtship dance, like many other species of the crane family.

Appearance

The Brolga crane reaches a height of up to 1.25 meters. Its plumage is a medium to light silver gray, its wingspan is 1.7 to 2.4 meters.

The adult Brolga crane wears a striking, wide ribbon at the back of the head. This is still missing in the young birds. Adult male birds weigh almost seven kilograms and female birds a little less than six kilograms.

food

Brolga cranes feed on a wide variety of marsh and aquatic plants, insects and invertebrates as well as frogs . The tubers of the sedge " Eleocharis dulcis " play a major role in their diet , they even dig for it with their beaks in the ground. On agricultural land , they also eat rice, maize and cereal grains.

Distribution and existence

Brolga cranes can be found in large areas of northern Australia but also in the southeast of mainland Australia. They are also found in southern New Guinea . Occasional birds are spotted in New Zealand . The Brolga crane is considered a resident bird that only roams around in the region when it rains heavily and when it is long-lasting. Outside the breeding season, the family groups give up their territoriality. Then you also meet large accumulations in coastal wetlands.

The number of adult birds is estimated at 20,000 to 100,000; the species is not classified as endangered. However, the International Crane Foundation began breeding brolga cranes with three breeding pairs in 1972, most of which are descended from the birds now in zoos. The greatest threat to this species of bird is the loss of wetlands.

Systematics

The Brolga crane is closely related to the Sarus crane , which is found in both Australia and Southeast Asia . It can easily be confused with this species due to its similar appearance. In the Sarus crane, however, part of the neck is also colored red, while the red band in the Brolga crane is limited to the back of the head.

The brolga crane is also closely related to the gray crane and, to a certain extent, to the South African paradise crane .

Social behavior

Brolga cranes mostly live in small family groups of three to four birds. Usually it is the adult birds with their offspring, although groups have also been observed that were not related to each other. The larger flocks that can be observed outside the breeding season in the coastal wetlands consist of a larger number of such family groups and do not form a large social unit. This can be seen from the fact that the family groups separate themselves from the others and coordinate their daily activities with one another and not with the whole group.

Reproduction

Grus rubicunda

Like the other crane species, the Brolga crane shows a distinctive courtship dance. The dance begins with a bird picking up grass with its beak, throwing it into the air and catching it again with its beak. The following sequence of movements includes one meter high jumps in the air, performed with outstretched wings, straightening the body, bowing, walking, shouting and lowering the head. Occasionally only a brolga crane dances in front of its companion; more often, however, both birds dance together. Occasionally a group of up to a dozen birds will also dance together.

The courtship and breeding season is less determined by the season than by rainfall. During the breeding season, the troops and family groups separate into pairs, each of which occupies a territory in wetlands. If their habitat offers good feeding conditions, the territories are very small. The nests of the closely related Sarus crane are often found in the same region.

The nest is built by both parent birds from twigs, grass and other plant material on small, dry elevations in the wetlands. If grass is not available, the birds use clay or aquatic plant roots that they dug out. Occasionally they also use an abandoned swan's nest or lay their eggs on the bare ground.

The clutch usually consists of two spotted eggs, which are laid two days apart. Both parent birds breed and then take care of the young birds. The chicks have gray down plumage and weigh about 100 grams when they hatch. They can leave the nest after one to two days and switch to their juvenile plumage at around four to five weeks old. In the event of danger, the chicks remain in place while the parent birds try to mislead the potential enemy. The young birds remain with the adult birds for at least 11 months. If these do not breed again, they will tolerate the presence of their adult offspring for up to two years.

Brolga cranes in Aboriginal mythology

In Australian Aboriginal mythology (the so-called dream time ), Brolga was a young woman of extraordinary beauty and an excellent dancer. She mastered the old dances in which she walked like an emu and swirled like the wind . She also invented new dances that told the stories of ghosts and that of the Australian fauna . Members of tribes even far away came just to see her, and the more she danced, the more famous she became. Occasionally the ancients of her tribe worried that because of her beauty and fame, she might become vain and conceited. But they were wrong. Brolga always remained humble and reserved.

One day Brolga went out into the wide plain alone to dance to herself. There she discovered an evil spirit who wished to possess her. He came in the form of a whirlwind and carried her away with him. Her tribe was looking for her, but the wind had even left her footprints with it. They searched for many days until they saw the whirlwind far away on the plain and Brolga beside him. They all ran out to save her, threatening with their spears and boomerangs . But the whirlwind was turning faster and faster and the evil spirit shouted that if he couldn't have her, no one should have her, and so the wind took her with it to heaven.

Not long after, a bird appeared that no one had seen before. It was a beautiful, big and gray bird. Slowly he spread his wings and began to dance. He walked and floated with the same grace that Brolga was once famous for. It was then that the people of their tribe realized that Brolga had escaped the evil spirit and turned into a bird to return to them from heaven and dance for them.

The Brolga is also a figure in the Dreamtime creation story .

At the beginning of the earth's formation, there was complete darkness and Brolga and Emu argued about whether the earth needed light. Brolga was against it because he said that things should not be changed as they are. The emu believed that animals need light to live. They argued and couldn't agree. Then Brolga made the emu flightless in anger by clipping the emu's wings. Thereupon Emu took revenge and hurled Brolga's egg into the sky; it exploded and became the sun. Now there was light and everyone could see the grandiose achievements of the so-called Heavenly Father of Dreamtime.

literature

  • JD MacDonald: The Illustrated Dictionary of Australian Birds by Common Name. Reed, Frenchs Forest 1987, ISBN 0-7301-0184-3 , p. 40.
  • P. Slater, P. Slater, R. Slater: The Slater Field Guide to Australian Birds. Landowne Publishing, Sydney 1995, ISBN 0-947116-99-0 .
  • Wolfgang Mewes, Günter Nowald, Hartwig Prange: Cranes - Myths, Research, Facts. G. Braun Buchverlag, Karlsruhe 1999, ISBN 3-7650-8195-7 .
  • R. Lewis: An Introduction to the Dreamtime. Australian Aboriginal mysticism explained and explored. Fountainhead Press, Canning Vale DC 2002, ISBN 0-9578530-2-5 .

Web links

Commons : Brolgakranich ( Grus rubicunda )  - album with pictures, videos and audio files