Gouldian finch (Erythrura gouldiae)

Gouldian finches (Erythrura gouldiae) are small, colourful passerine (three toes pointing forward and one back) birds of the family Estrildidae found in the north of Australia. The number of Gouldian finches in the wild has decreased markedly during the twentieth century, and they are listed as endangered (under the Environment Protection and Biodiversity Conservation Act 1999) and as near threatened (under the International Union for Conservation of Nature Red List).

The trapping of finches began in the Kimberley in 1897, and for the next eighty years, the Gouldian was trapped and exported in larger numbers than any other species of finch. Because of their striking plumage, Gouldian finches were exported in large numbers around the globe until 1959 when the Australian government banned exportation of Australian fauna. This has led to the existence of large quantities of breeding stock in captivity, although the birds continue to face a number of threats in the wild. Although trapping for the aviary trade was banned in 1981, populations continue to decline at uneven rates in different regions of northern Australia.

Background

Gouldian finches are small grass finches about thirteen to fifteen centimetres long, with a bright green back, purple/mauve breast, and a yellow underbelly. About 75 per cent of birds have black heads, the rest have red heads, with some yellow-face birds (a genetic lack of red pigment) occurring more rarely. These were once considered three different kinds of finches, but it is now known that they are genetic variations within the one species in the wild. Several scientific studies have shown that red-headed Gouldians dominate those with black heads, and both dominate those with yellow heads. Although both males and females are highly colourful, males tend to exhibit brighter plumage than females. Males have bright purple chests, while females tend to have a mauve chest. Selective breeding in captivity has led to the development of colour mutations which vary by country, with blue, pastel green, pastel blue, yellow, silver and even albino Gouldians bred in the United States.

Newly hatched Gouldians do not begin to develop feathers until they are approximately twelve days old and are pinkish in colour. Their mouths are characterised by dots resembling those on a domino with tubercles that reflect the light, most likely to aid their parents in finding them in dark nests, although this hypothesis has yet to be empirically confirmed. Juvenile Gouldians are olive green on their backs, wings and tail feathers, and grey on their heads, necks and sides. Black beaks are reddish on the tip.

Gouldian finches rarely make noise, with the exception of an occasional high-pitched whistle. They can live up to five years of age in the wild, although they are at particular risk in their first year of life.

The Gouldian finch was first described in 1844 by well-known British ornithologist John Gould. He named the bird in honour of his wife Elizabeth, and it is often referred to as the Lady Gouldian finch.

The Gouldian finch is classified as class Aves, order Passeriformes, family Estrildidae, genus Erythrura, species E. Gouldiae.

Gouldian finches are found in tropical savannah woodland in the northern parts of the Australian continent, ranging from Cape York Peninsula in northern Queensland to the uppermost Northern Territory and the Kimberley region in Western Australia. They tend to be nomadic within a small area of about forty kilometres square, moving when necessary to find water or food. They must live near water sources, as they need to drink several times a day.

Overview

Gouldian finches feed primarily on sorghum grass seeds and, during the wet season, on cockatoo grass (Alloteropsis semialata), spinifex grasses (including Triodia acutispicula, T. bitextura, T. bynoei, T. pungens and T. schinzii) and golden beard grass (Chrysopogon fallax).

The Gouldian breeding season runs from January to April. The male courtship dance entails the male dancing and ruffling his feathers to enhance his size and display his bright plumage. Unlike other finch species in Australia, cavity nests are formed in tree hollows of snappy gum or northern white gum (Eucalyptus brevifolia) in the western part of its range and salmon gum (E. tintinnans) in the east, and occasionally in termite nests. The female lays between four and eight eggs, and both male and female brood the eggs during the day, with the female roosting throughout the night. The eggs incubate for about thirteen days, and when hatched, both parents care for the young for between nineteen and twenty-three days. Juvenile finches are independent at forty days.

Several factors threaten the survival of the Gouldian finches, including feral cats, bushfires, grazing by feral horses and feral pigs, unlicensed bird trappers and diseases such as air-sac mite (Sternostoma tracheacolum). Studies by Associate Professor Sarah Legge and Dr. Sarah Pryke have revealed the impact that bushfires have on the grasses that are critical to the survival of Gouldian finches. During the changeover between the wet and dry seasons, the Gouldians rely on two species of spinifex for seed, and these will only produce seeds if they have not been burnt in the last two or three years. Careful fire management across the central Kimberley in a program called Ecofire has already led to an increase in the number of finches in the region.

Several other recovery plans are in place to rebuild Gouldian finch numbers in the wild. The Australian Wildlife Conservancy is involved in researching Gouldian finches and protecting the remaining populations at Mornington-Marion Downs and the Artesian Range in the Kimberley region, and Wongalara and Pungalina in the Northern Territory. The federal Department of Environment and Energy is monitoring the waterholes in the Yinberrie Hills in the Northern Territory and using radio tracking to monitor the movement and feeding patterns of Gouldian finches. In 2017, they released a threat abatement plan for predation, habitat degradation, competition and disease transmission by feral pigs with the aim "to guide and coordinate Australia's response to the impact of feral pigs on biodiversity." The World Wildlife Fund is working with the Kija Rangers and the Kimberley Land Council to prevent late-season fires by conducting early controlled burns in key Gouldian habitats, and is partnering the Bardi Jawi and Nyul Nyul Rangers on the Dampier Peninsula Gouldian Finch Project to protect a small colony of breeding finches. In 2023, continued destruction of Gouldian habitats in Binbybara from global climate change, cyclones, and economic development further reduced the finch's available breeding grounds.

The World Wildlife Fund sees the Gouldian finch as 'a classic "canary in the coal mine" species', as its decline suggests that many other species that share its habitat are also under threat—these include goannas, snakes, other granivorous birds and some species of mammals.

Bibliography

Abbatangelo, Ben. "Binybara Is Not Just Home to the Gouldian Finch. It's Part of the Larrakia Nation. And It Deserves Protection." The Guardian, 11 July 2023, www.theguardian.com/commentisfree/2023/jul/11/binybara-is-not-just-home-to-the-gouldian-finch-its-part-of-the-larrakia-nation-and-it-deserves-protection. Accessed 17 Jan. 2025.

"Fire Management. How Are Gouldians Affected by Wildfires?" Save The Gouldian Fund, savethegouldian.net/?page‗id=73. Accessed 17 Jan. 2025.

"Gouldian Finch." Birds in Backyards, www.birdsinbackyards.net/species/Erythrura-gouldiae. Accessed 17 Jan. 2025.

"Gouldian Finch." World Wildlife Fund, www.wwf.org.au/what-we-do/species/gouldian-finch. Accessed 17 Jan. 2025.

Pryke, Sarah R. "Fiery Red Heads: Female Dominance among Head Colour Morphs in the Gouldian Finch." Behavioral Ecology, vol. 18, no. 3, 1 May 2007, pp. 621–27, doi.org/10.1093/beheco/arm020. Accessed 17 Jan. 2025.

Pryke, Sarah R., and Simon C. Griffith. "Red Dominates Black: Agonistic Signalling among Head Morphs in the Colour Polymorphic Gouldian Finch." The Royal Society, 22 Apr. 2006, doi: 10.1098/rspb.2005.3362. Accessed 17 Jan. 2025.

Tidemann, Sonia C., et al. "Parasitism of Wild Gouldian Finches (Erythrura Gouldiae)." Journal of Wildlife Diseases, Jan. 1992, pp. 80–84.

"Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs (Sus Scrofa)." Department of the Environment and Energy, Commonwealth of Australia, 2017, www.environment.gov.au/biodiversity/threatened/publications/tap/feral-pig-2017. Accessed 17 Jan. 2025.