The Gouldian Finch, Erythrura gouldiae (or Chloebia gouldiae), also known as the Lady Gouldian Finch, Gould's Finch or Rainbow Finch , is a colourful passerine bird endemic to Australia. There is strong evidence of a continuing decline, even at the best-known site near Katherine in the Northern Territory. It is bred in captivity, but in 1992 it was classified as ENDANGERED under criteria C2ai. This was due to the fact that a: the viable population size was estimated to be less than 2,500 mature individuals and b: no permanent subpopulation was known to contain more than 250 mature individuals and finally c: that a continuing decline was observed in the number of mature individuals. It is currently subject to a conservation program.
Taxonomy
The Gouldian Finch was described by British ornithological artist John Gould in 1844 and named after his wife Elizabeth. It is also known in its native country as the Rainbow, Gould, or Lady Gouldian Finch (although Mrs Gould did not hold the title Lady). It is a member of the weaver-finch family Estrildidae, which is sometimes considered a subfamily of Passeridae.
Exported to Europe, the United States and Japan has provided this bird with a number of colour mutations such as the blue back, pastel, silver, yellow back and even white.
Description
Gouldian Finches are about 130–140 mm long. Both sexes are brightly coloured with black, green, yellow, red and other colours. The females tend to be less brightly coloured. One major difference between the sexes is that the male's chest is purple, while the female's is a lighter mauve colour.
Gouldian Finches' heads may be red, black, or yellow. People used to think they were three different kinds of finches, but now it is known that they are colour variants that exist in the wild.[1] Selective breeding has also developed mutations (blue, yellow and silver instead of green back) in body colour and breast colour.
Juveniles have distinctive colours. Their heads, sides and necks are grey, and their backs, wings and tail feathers are olive green. Their undersides are pale brown. Beaks are blackish with a reddish tip. Their legs and feet are light brown. Newly hatched Gouldian finches are pink and naked until about 12 days old when the beginnings of feathers start to appear. Very young birds also have blue, shiny structures on the sides of their beaks to help their parents see them in the dark.
Distribution and habitat
Black headed male Gouldian Finch
Gouldian finch mutations: white gouldian finch and yellow gouldian finch mutation
A young Gouldian Finch (first day out of the nest) - note the shiny blue on the side of its beak
A young Gouldian Finch with the beginnings of bright adult plumage
Female (left) and male Gouldian Finches
This bird is found in northern Australia: the Cape York Peninsula through north-west Queensland and the northern Northern Territory to the Kimberley region of Western Australia. Their habitat is tropical savanna woodlands. The birds are nomadic within a relatively small area [ approx40 sq kilometers and only move when water or food become scarce.
Conservation status
The numbers of Gouldian Finches have decreased quite dramatically during the 20th century. Their habitat has been reduced or altered. Early research indicated a parasite called air sac mite, was responsible for the decline of the Gouldian. This is no longer considered to be a major factor. In general, Gouldian Finches are susceptible to diseases and viral infections. Their beautiful colours mean that they are easily caught by predators. Fires are listed as the number-one threat to the natural populations. The total number of Gouldian finches altogether is not low, however, because they are among the most popular pet birds, and are bred in captivity for the pet trade.
Actions have been taken and are underway to implement a recovery plan to recover and conserve its natural habitats, such as building protective fencing to prevent damage by cattle. Attempts at reintroduction have so far proved unsuccessful; It was also suggested to develop management guidelines for land-holders about appropriate land management, promoting the recovery programme and Gouldian Finches conservation.
Behaviour
Gouldian Finches are very social birds and are often found in large flocks. Flocks used to consist of up to 500–1000 individuals. Gouldian Finches are quiet birds that generally stay away from places where people live. Their calls are not heard over great distances.
Feeding
Like other finches, the Gouldian Finch is a seed eater. During the breeding season, Gouldian Finches feed mostly on ripe or half-ripe grass seeds of Sorghum Spc. During the dry season they forage on the ground for fallen seed. During the wet season, Spinifex grass seed [Triodia Spc] is an important component of their diet. So far Gouldians have been recorded as consuming 6 different species of grass seed but during crop analysis researchers have never so far found insects.
Breeding
Gouldian finches generally make their nests in holes in trees, generally within a kilometre of water. They usually breed in the early part of the dry season, when there is plenty of food around. The male courtship dance is a fascinating spectacle. When a male is courting a female, he bobs about ruffling his feathers to show off his colours. He expands his chest and fluffs out his forehead feathers. After mating, a female lays a clutch of about 4–8 eggs. Both parents help brood the eggs during the daytime, and the female stays on the eggs at night. When the eggs hatch, both parents help care for the young. Gouldian Finches leave the nest at between 19 and 23 days and are independent at 40 days old.
Young Gouldians are very fragile until their final moult. Some breeders believe parent-raised Gouldians have greater success rearing young than those fostered by other species, such as society or spice finches.
It has been shown scientifically that female finches from Northern Australia are controlling the sex of their offspring, according to the head colour of their male counterpart. Gouldian Finches are incompatible with Gouldian Finches with a different head colour and mating with a Gouldian Finch with the wrong head colour (black-head with red-head etc.) usually has fatal results for the chicks — female chicks especially will die, while male chicks have a better chance of survival. Therefore, with a wrong head colour mating, the female will lay fewer eggs with more male offspring.[2][3][4]
Aviculture
They need premium finch food, fresh water every day, gravel, a cuttlebone, perches, vitamins (the blue-blacked ones can not produce their own vitamin A, they especially need vitamins in their water). Water should be changed every day. Gravel should be replaced once a month and whole cage should be cleaned and disinfected. The Gouldian finch can be difficult to breed outside its native climate of Australia but does well when given the right conditions. Grit and cuttlebone are an important component of a finches diet. Many mutations occur in aviculture. Yellow, dilute, blue, silver, white and even albino gouldian finches. More information may be obtained from www.savethegouldian.org/
Trivia
Gouldian finches are used as the ViewSonic logo, comprising of three birds perched on a greenish branch.
References
External links
