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. Taxonomy The Gouldian finch was described by British ornithological artist John Gould in 1844 as Amadina gouldiae, in honour of his deceased wife Elizabeth. The specimens were sent to him by Benjamin Bynoe although they had been described some years before by Jacques Bernard Hombron and Honoré Jacquinot. It is also known as the rainbow finch, Gould's finch, or the Lady Gouldian finch and sometimes just Gould. The Gouldian finch is sister to the parrotfinches in the genus Erythrura. Description 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. Gouldian finches are about 125–140 mm long. Gouldian finches' heads may be red, black, or yellow. Formerly considered three different kinds of finches, it is now known that these are colour variants that exist in the wild. Selective breeding has also developed mutations (blue, yellow and silver instead of a green back) in both body and breast colour. There are several "prominent rounded tubercles" with an "opalescent lustre" at the back of the gape. These tubercles are commonly (and incorrectly) described as phosphorescent in spite of much scientific evidence to the contrary. It is believed that these tubercles simply reflect light and are not luminescent. Distribution and habitat Prior to the Australian government's ban on the export of Australian fauna, Gouldian finches were exported worldwide. These birds have resulted in viable breeding populations being held in many countries. Conservation status The number of Gouldian finches has decreased quite dramatically during the 20th century. Their habitat has been reduced or altered. Early research indicated a parasite called the air sac mite was responsible for the decline of the species. 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 primary threat to the natural populations. Behaviour Outside the breeding season, Gouldian finches often join mixed flocks consisting of long-tailed finches and masked finches. Flocks can consist of up to 1,000–2,000 individuals. During the breeding season, they