Lady Gouldian Finch
Gouldian Finch, chloebia gouldiae, Adult standing on Branch
The Gouldian finch (Chloebia gouldiae), also known as the Lady Gouldian finch, Gould’s finch or the rainbow finch, is a colourful passerine bird that is native to Australia.
Both sexes are brightly coloured with black, green, yellow, and red markings. 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
Feeding
Like other finches, the Gouldian finch is a seed eater. They eat up to 30% of their bodyweight each day. During the breeding season, Gouldian finches mainly feed on ripe and half-ripe grass seeds of sorghum. During the dry season, they mainly forage on the ground for seeds. During the wet season, spinifex grass seed (Triodia sp.) is an important part of their diet. So far Gouldians have been recorded eating six different species of grass seed, but researchers have yet to find evidence of insect consumption
Breeding
Newly-hatched Gouldian finch chicks
A young Gouldian finch (first day out of the nest) – note the blue nodules on the side of its beak
Gouldian finches will usually make their nests in tree-holes. They usually breed in the early part of the dry season, when there is plenty of food around. When a male is courting a female, he bobs about and ruffles his feathers in an attempt to show off his bright colors. He will expand his chest and fluff out the feathers on his forehead. After mating, the female will lay a clutch of about 4–8 eggs. Both parents help brood the eggs during the daytime, and it is the female who stays on the eggs at night. When the eggs hatch, both parents care for the young. Gouldian finches leave the nest after between 19 and 23 days and are completely independent at 40 days old.
Gouldian finches have brightly coloured gapes and call loudly when the parent birds return so that they are able to find and feed their mouths in the dark nest.
It has been shown that female Gouldian finches from Northern Australia can control the sex of their offspring by choosing mates according to their head color. A certain amount of genetic incompatibility between black and red-headed birds can result in high mortality (up to 80%) in female offspring when birds of different head colours mate. If the female mates with a finch of different head colour, this genetic incompatibility can be addressed by over-producing sons, up to a ratio of four males to one female. This is one of the first proven instances of birds biasing the sex of their offspring to overcome genetic weaknesses.
