The Gouldian Finch is a small variegated and brightly coloured finch endemic to Northern Australia. Of the ‘Passeriformes’ order and ‘Estrildidae’ family of birds, it is also known as the ‘Rainbow Finch’, ‘Gould’s Finch’ or ‘Lady Gouldian Finch’.
Gouldians live in isolated areas of the tropical savanna and woodlands of Northern Australia. Main populations are in the Kimberley region of Western Australia and in the top end of Northern Territory, with smaller scattered isolated populations still surviving in Northern Queensland. Gouldians live in flocks, with small groups up to 20 birds and larger flocks reaching numbers of 120 strong.
Decline and Stabilisation of Numbers in the Wild
The Gouldian was officially classed as an endangered species over the last decade with figures as low as 2,500 left in the wild in 2007. According to the IUCN Red list of threatened species – population stability has been demonstrated in the monitoring of species populations at the best-known site just outside Katherine (O. Price per Woinarski in litt. 2007). Monitoring at central Kimberley has shown no evidence of a decline from 2004 to 2007 (S. Legge in litt. 2007), and the overall population is estimated to be somewhat stable or possibly increasing (Garnett et al. 2011).
One major review concluded that the population was around 2,400 mature individuals at the end of the 2010 breeding season, with falls to a yearly minimum around 1,000 individuals in the wet season (Garnett et al. 2011). In the Mornington area there are said to be around 700 birds and in the east Kimberley region there are up to a dozen isolated breeding populations with between 30 to over 100 birds each. Numbers in the Dampier Peninsula region are yet unknown as are the extent of other remaining regions, as the birds are largely nomadic and change their nesting and feeding locations depending on environmental conditions throughout the year.
White-breasted Gouldian Finch
Habitat, Breeding and Feeding
Gouldians nest in the hollows of native trees and eucalypt forests. The largest breeding population is said to live just north of Katherine in the Northern Territory, although may travel to different habitats at various times of the year depending on food and seasonal environmental conditions.
For much of the dry season birds remain in their native breeding habitat in hilled and woodland, with a variety of wooded habitats, shrubland or lowland environments are utilised more throughout the wet season. This makes it difficult to correctly account for gouldian numbers, yet dedicated conservation programs are underway including waterhole monitoring projects to gauge and record the declining, or in some regions ‘stabilising’ numbers.
The Gouldian feeds largely on grass seeds, although some insects and small invertebrates may be supplemented. Many environmental factors are involved with the declining or stabilisation of numbers such as: waterhole degradation due to grazing; extended dry seasons and altered fire regimes. The increases population of grazing herbivores such as cattle, horses and feral pigs is thought to have an impact on wet season grasses, an important staple effecting numbers when the annual gouldian count is at its lowest.