Gouldian finch
| Gouldian finch | ||||||||||||
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Gouldian finch ( Chloebia gouldiae ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Chloebia | ||||||||||||
| Reichenbach , 1863 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Chloebia gouldiae | ||||||||||||
| ( Gould , 1844) |
The Gouldian finch ( Chloebia gouldiae , Syn . : Erythrura gouldiae ) belongs to the family of the beautiful finches (Estrildidae). The finches are part of the fauna of Australia and are a polymorphic species . In the same population there are usually two, and occasionally even three, different variations in the color of the skull. They mate with one another without restriction, so that they are not differentiated as subspecies .
Gouldian finches have become rare in their homeland and are classified by the IUCN as 
(= Vulnerable - endangered). This colorful feathered bird, which also occurs in the wild in three different shades of color, is kept as an ornamental bird all over the world.
The British naturalist and animal painter John Gould discovered this fine finch species during his trips to Australia in 1838 and 1840 and described it scientifically in 1844. In memory of his wife Elizabeth Gould , who accompanied him on these trips and died shortly afterwards, he called her Lady Gould's Amadine . The birds described by Gould were black-headed Gouldian finches. The red- and yellow-headed variants of this species were still considered to be separate species at the time of their discovery.
Appearance
Appearance of adult birds
Adult Gouldian finches are extremely colorful birds, in which the head plumage can vary greatly. There are also black-, red- and yellow-headed variants in the wild populations.
Black-headed Gouldian finches are the most common birds seen in the wild. Black-headed birds with a red beak tip are pure breeding in terms of head color. Black-headed birds with yellow beak tips are genetically yellow-headed. With them, however, the black melanin overlays the yellow of the head mask. Yellow-headed birds are rarely seen in the wild. It is estimated that there is only one yellow-headed bird for every 3,000 black- and red-headed birds. Yellow-headedness is due to a loss mutation. Birds with this head color are not able to convert yellow carotenoids into red plumage pigments . The trait is inherited in a dominant-recessive manner .
In red- and yellow-headed birds, a black band around the back of the head separates the head color from the rest of the plumage. In all color variants there is also a light blue band on the back of the head and throat, which gradually merges into the green back plumage.
The plumage of the wing covers is also colored green in Gouldian finches. The purple breast, which is sharply set off against the yellow feathered belly, is striking. This lightens towards the tail almost to a white. The rump and the upper tail cover are light blue. The eyelid ring that surrounds the dark brown eyes is also light blue. The bill and feet are horn-colored.
The body length of the birds is about eleven centimeters in both sexes. From the head to the ends of the two central tail feathers, their length is between 13 and 15 centimeters.
Appearance of nestlings and young birds
After hatching from the egg, the nestlings are light, flesh-colored and completely feathered. Like all fine finch species, they too have a striking throat markings. They have two blue and one yellow papilla in each of the beak corners. When the beak is torn open, there are five black dots on the throat, two on the tongue, two inside the tip of the upper beak and a horseshoe-shaped mark inside the lower beak. In the parent birds, showing them triggers the feeding behavior. Presumably, on the basis of these characteristics, they even distinguish their offspring from those of alien species. This throat drawing is also important for the systematic classification within the finch family.
Young birds are drawn much less colorfully until they moult in adult clothing. The top of the body is colored gray-green. The head also shows this gray-green. The top of the beak is black, while the lower beak is a little reddish or yellowish in color in the middle.
Vocalizations
Gouldian finches are flocking birds that insure themselves that their conspecifics are close by constantly quietly calling . This call also sounds during the flight, but is usually so quiet that a person can only hear it when he is in the immediate vicinity of the birds. The call becomes sharper and changes to a tremor when a single bird is a little further away from the flock or the partner. If the other members of the swarm or the partner are not visible, the tremor turns into a loud and far- reaching zrüie-iet .
The song of the Gouldian finches is described by Horst Bielfeld , who is considered one of the best German-speaking connoisseurs of the beautiful finches, as a quiet, sometimes pearly, whispering and grinding chirping . If it is directed to a female as courtship song, then it is usually initiated with the Nestlock call zrüit . The cocks of the Gouldian finches start practicing courtship singing very early. This is one of the ways to determine the sex of the juveniles. In such practice chants , however, this is missing at the beginning of the chant.
Nestlings and fledglings beg their parent birds for food with a very fast wiwiwiwi . A distinction can be made between two different types of call for warning calls. With the double call sett-sett, Gouldian fathers warn their fellows of dangers. With a sharp djit, Gouldian fathers warn the young birds in particular, who keep quiet in a hiding place when they hear this call.
Distribution area and migratory movements
Gouldian finches are one of Australia's finest finches . They occur in the north of the Australian continent up to the 19th parallel. Only the Cape York region overgrown with rainforest is not populated by them.
Long migrations are typical of Gouldian finches within this distribution area. In general, they stay during the breeding season in the savannas of the Kimberley region , the northern Northern Territory and northwestern Queensland . Outside the breeding season, they can be found in the coastal areas because there is sufficient food available here due to the longer and later rains. Migration begins at the end of the rains, when the vegetation withers, the waterholes increasingly dry up and only dry grass seeds can be found that have fallen out of their panicles and are lying on the ground. Gouldian finches are very reluctant to take up their food from the ground and, as a rule, the migratory movements start when there is no longer sufficient food to be found in the panicles. Sometimes both clutches and nestlings are left in the lurch.
The migratory movement of the Gouldian swarms is, at least initially, undirected. The swarms are looking for new food grounds and sufficient watering points. As a rule, the swarms move northwards because the rains last longer here. In areas where there is no rainfall, Gouldian finches are occasionally absent for years.
habitat
The range of the Gouldian finches includes the Kimberley region , which is bordered in the west by the Indian Ocean, in the north by the Timor Sea and in the south by the Great Sand and Tanami Desert. The Kimberley region, in which Gouldian finches are still relatively common compared to the other regions, is the hottest area in the entire southern hemisphere. Inland, daytime temperatures between 40 and 45 ° C are reached in the shade. At night, the temperature rarely falls below 35 ° C. From November to April there is very heavy rainfall. The humidity during this time is between 80 and 90 percent.
Gouldian finches are adapted to these extreme climatic conditions. They are very lively at temperatures between 30 and 45 ° C and even then take long sunbaths. Other bird species, however, seek shade at these temperatures. Also in the Northern Territory , where they move in search of optimal living conditions during their migrations, they prefer to stay in the seasons when high daytime temperatures and high humidity prevail at the same time. During this time they also find the semi-ripe seeds and insects that are part of their food spectrum.
Predators
Snakes and birds of prey are the predators most commonly preying on adult Gouldian finches. Snakes are probably the reason why Gouldian finches spend the night on the thinnest branches of their sleeping trees. Their reluctance to fly into a tree hole is also due to their caution towards snakes. Compared to approaching birds of prey, Gouldian fathers flee into the interior of eucalyptus trees or into nearby bushes. Similar to mask , Spitzschwanz- and Gürtelamadinen and the zebra finch is also evident in the Gouldians a drinking behavior as " suction Rinken is called" and for pigeons is typical. This drinking behavior, which clearly differs from the sip-by-sip drinking of other birds and with which a large amount of water is consumed very quickly, these species reduce the time they spend exposed at a watering place. This reduces their risk of being hit by birds of prey.
Nestlings are also endangered by a number of other animal species. Ants eat young birds alive when they are found in the nest. Some species of flies lay their eggs in the nests in such a way that the hatching larvae eat the young birds. The predators of nestlings also include smaller lizards. These are dangerous to the adult Gouldians only in exceptional cases.
Reproduction
The breeding season of the Gouldian finches coincides with the rainy season in this region; During this time, the night temperatures rarely drop below 30 ° C. The nest is preferably built in caves in the eucalyptus trees. The clutch usually consists of six eggs and is incubated by both adult birds. The young hatch after 14 days and are fed by the adult birds with half-ripe grass seeds, soft beetles, spiders and winged termites, whose swarming time also falls during the rainy season. Depending on the length of the rainy season, several broods follow one another. The not yet sexually mature young birds help with the rearing of the following broods.
Systematics
Within the family of the magnificent finches, the Gouldian finches are particularly close to the South Sea parrot finches and the real parrot finches . It was therefore systematically assigned to this genus for a while. The close relationship is suspected mainly due to the similar pharynx drawings. Similarities exist with regard to the color division of the plumage, the song and the courtship with the nuns . Since 1962 the Gouldian finch has been assigned to the genus Chloebia as the only species . The species is seen as a link between the nuns and the rice finches and the real parrot finches . In Australia, species is often given with the synonym Erythrura gouldiae and thus assigned to the parrot finch.
Man and Gouldian finches
The establishment as an ornamental bird
The first living Gouldian finches were brought to Great Britain in 1887 and aroused great interest among pet bird keepers because of their strikingly colored plumage. In Germany, Gouldian finches were first shown at a large bird show in Berlin in 1896 . Up until the 1930s, almost all birds that were traded in Europe came from imports from Australia. Only the Englishman PW Teague succeeded in building up a breeding line with which he successfully bred from 1930 to 1946. To this day, the predominant husbandry recommendations go back to the publications he published on breeding and handling. Feeding a mixture of silver millets , Manna millet , Senegal millet and niger and the feeding of sprouted seeds, which is practiced by successful Gouldamadinenhaltern also go back to Teague.
Despite Teague's success in breeding this species of bird, the number of birds bred in Europe was nowhere near enough to meet demand. Most of the birds kept in Europe came from the wild until the beginning of 1960 .
threat
Due to the earlier strong catch for bird keeping, the wild populations were greatly reduced. Today the remaining natural habitats of the Gouldian finch are still threatened. The IUCN estimates the wild population of the species to be less than 2500 animals and classifies the species as "critically endangered".
The fishing methods in Australia
Klaus Immelmann , a behavioral scientist who specialized in zebra finches , stayed longer in the Kimberley region for research purposes at the end of the 1950s . He also had the opportunity to observe the practice of bird trapping in Australia from close up: in 1958 alone 55 professional bird trappers were out in the Kimberley region, who caught birds in large folding nets at the few watering holes. Many birds perished while they were caught because they were injured or killed directly by the hinged nets. The birds were well supplied with food and water by the trappers, but another large proportion of the birds caught were killed during transport to the ports in northern Australia. From the north of Australia, they were brought by merchant ships to the southeast of Australia and then shipped to Europe or North America . It was estimated that for every fine finch that survived the first year of captivity, there were three hundred to four hundred birds that died during capture and subsequent transport.
Gouldian lady trade after the Australian export ban
On January 1, 1960, Australia issued a comprehensive export ban on all Australian animals. Breeding in Europe and North America was still very rare at that time. The continuing demand for Gouldian finch on the European and North American market was mainly met by Japanese breeders . The Japanese were said to have a special breeding ability at that time. In fact, however, they had primarily solved the problem of feeding the young birds. In the wild, nestlings and young birds are mainly fed by their parents with flying termites, soft beetles and spiders. This high protein diet is difficult to provide in captivity. Captured birds often do not adopt mealworm larvae or ant pupae . The Japanese developed the so-called egg millet as a substitute feed . Millet - usually the large-grained silver millet - is coarsely ground and then coated with egg yolk.
The Japanese also developed the breeding of wet nurses among the beautiful finches. They mainly use Japanese gulls for this. In this ornamental bird species, both parent birds are busy breeders and they are easy to keep. Breeders achieved the greatest breeding success when the Gouldian finches were raised by three male gulls each. Like most of the finches, Gouldian finches always lay new clutches when their eggs have been stolen. A single pair of Gouldian finches produces up to 60 eggs per year; it takes three groups of three Japanese gulls to raise the young birds of this couple.
This nursing practice is practiced worldwide today. In the Netherlands in particular there are producers who use Gouldian finches in this way for the European market. According to Horst Bielfeld's experience, birds that descend from parent birds that have to produce eggs almost without a break are particularly prone to disease. Their mortality rate during the first moult is said to be around 50 percent. The birds are also often misrepresented, that is, they see their sexual partners in the gulls and court them while they take no notice of their conspecifics. Gouldian finches, which have an incorrectly developed breeding and feeding instinct, also reproduce through nursing. Lovers who want to set up a natural breed with these birds have the experience that these Gouldian finches breed unreliably, do not feed their young or throw them out of the nest.
Despite these disadvantages, birds raised in this manner will not go off the market. Natural breeding birds are much more expensive than those from foster breeding. In the normal zoo animal trade, they are usually not offered at all. In order to acquire birds, one usually has to find out through organizations such as the Association for the Protection of Species, Bird Keeping and Bird Breeding (AZ) eV which private individuals are breeding enthusiasts in the vicinity.
Housing requirements
Compared to the more robust zebra finches , which also belong to the magnificent finches, the Gouldian finch is a more demanding ornamental bird. They thrive best at a constant minimum room temperature of 24 ° C and high humidity. Keeping them in free-range aviaries only makes sense if the birds always have access to a heated indoor enclosure. Large room aviaries are ideal conditions for keeping them. Then these sociable birds, which also breed in loose colonies in their home, can even be kept in a small flock. Cage is only useful if it is at least 80 cm long, 60 cm high and 50 cm deep. It shouldn't be a lattice cage, but a so-called box cage, in which only the front is latticed. The other fronts consist of boards, plywood, hard fiber or chipboard or plastic panels.
literature
- Horst Bielfeld : Das Prachtfinkenbuch - All species, their keeping, care and breeding. Eugen Ulmer, Stuttgart 1996, ISBN 3-8001-7327-1 .
- Horst Bielfeld: Gouldian finches - keeping, breeding and color variations. Eugen Ulmer, Stuttgart 1985, ISBN 3-8001-7364-6 .
- Jürgen Nicolai (Ed.), Joachim Steinbacher (Ed.), Renate van den Elzen, Gerhard Hofmann: Prachtfinken - Australia, Oceania, Southeast Asia. Eugen Ulmer Verlag, Stuttgart 2001, ISBN 3-8001-3249-4 .
- Peter Clement , Alan Harris , John Davis: Finches and Sparrows - An Identification Guide. Christopher Helm, London 1993, ISBN 0-7136-8017-2 .
- Graham Pizzey, Frank Knight: The Field Guide to the Birds of Australia. 9th edition. Harper Collins, Sydney NSW 2000, Australia 2012, ISBN 9780732291938 (pbk.).
Web links
- Videos, photos and sound recordings of Chloebia gouldiae in the Internet Bird Collection
- Chloebia gouldiae inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2013. Retrieved November 23, 2013.
