Gouldian Finch (Erythrura gouldiae) is a bold coloring finch, often called rainbow finch. It has brought dazzling fame as a cage bird and misfortune in the wild. Once widespread through the grassy sub-coastal woodlands of northern Australia, from the Kimberley’s to the Cape York Peninsula, it has now withdrawn from nearly half its range.
The colonies around the Gulf of Carpentaria and on the Cape York Peninsula have almost gone. Even in the Kimberleys and Arnhem Land, where it is still locally common in savannas dotted with tall trees around permanent waters, the flocks of thousands that flourished 50 years ago have dwindled to tens and hundreds. The causes may be trapping for the bird trade and too-regular firing of feeding grounds.
Gouldian Finches feed on a range of seeding grasses, not on the ground but by climbing and clinging to vertical spikes to pick out grains as mannikins do. They are also experts at catching flying ants in midair and during breeding become almost entirely insectivorous, feeding young on a protein-rich diet. Following their food, Gouldian Finches are partly migratory.
In the winter dry season, they shift coast wards as grasses die off inland, then follow the rejuvenating rains back in the summer wet to breed. Like most mannikins, Gouldian Finches are social birds, living together in small to large flocks. If flushed, they fly as a group to the very tops of nearby trees to sit and hop about with blue rumps conspicuously displayed and tails flicking deeply up and down.
They also join in daily bouts of sunbathing and drinking at pools; drinking is by sucking. There is no huddling or allopreening, however, nor do they sleep together in roost nests. Pairs court on horizontal twigs in the middle of trees. The male finch may hold a grass stem in pre-play but soon drops it. Fluffing his head and breast and raising his tail to highlight his colors, he sits in front of the female and bows and shakes, moving his bill speedily to and fro over the perch and occasionally wiping it.
Then he jerks quickly erect and, tail depressed, begins a whisper song with bill held down and head swinging from side to side. After repeats, males and females fly to the nest and copulate inside. Gouldian finches are the only Australian birds to nest exclusively in hollows in trees or termite mounds.
They are poor nest-builders putting together only the rudiments or not even that-but they do nest socially in loose colonies. Up to six pairs will nest in a single tree, some in the same hollow together.
Each rears two or three broods a season. Both parents incubate and brood in shifts, relieving one another inside the nest; only the female sleeps in the nest at night. After fledging, young may retain their juvenile plumage for six months or more, even breeding in it.
It is also known as Purple-breasted Finch, Purple-chested Finch, and Rainbow Finch.
Rainbow Finch is about 130-140 mm in length. The male bird has a crown and face mask black in most birds (75-80%), dull crimson in minority (25-30%), and ochre-yellow in rare defectives. Back and wings grass-green; rump, upper tail coverts blue; tail black, pointed.
Chin and throat black; breast band lilac; belly yellow; undertail white. The eyes are dark brown with a bill is ivory with red tips. Feet pale yellow. The female bird is a little duller, while the immature bird is a little dull ash-gray overhead to olive over back and tail, brown-white below; maxilla dusky, pale nodules at gape.
Gouldian Finch calls variations of reedy ssittt in contact and alarm, often repeated. However, the song of Gouldian Finch is faint high-pitched hisses and whines interspersed with clicking.
The breeding and nesting season is December-April. Normally the nest is rounded and rudimentary, of coarse dry grass, or none at all; in a hollow in a branch or termite mound. The clutch contains 4 to 8; pure white; eggs, that are oval in shape about 16 x 13 mm.
The incubation period is approximately 13-14 days, for both sexes. The young bird fledges in three weeks. The distribution of Rainbow Finch is patchy in northern sub-coastal woodlands from Kimberley’s to Arnhem Land and thinly to the central Cape York Peninsula: There are one or two races.
