The star finch’s diet consists primarily of ripe or half-ripe seeds which it forages for in grass and shrubland. This is occasionally supplemented by insects and spiders (2) (3) (5). The star finch may either take seeds directly from the seed heads of grasses or other plants, or may forage for fallen seeds on the ground, particularly during the dry season when grasses have died back (2) (3) (4) (5). It has also been known to capture insects in flight (3).
This species has a complex and intriguing courtship display. The female star finch performs an elaborate flight display (2) (5), holding a long piece of grass in her bill as she flies around the male with a fluttering, butterfly-like flight. As part of courtship, the male will also take a strip of long grass in his bill, and approach the perched female with his tail angled towards her and his spotted feathers fluffed out. The male then bobs up and down while turning the body from side to side, and at the end of the bobbing movements he makes a deep bow, singing all the while (2). If successful, mating will ensue (2) and the pair will usually commit to a monogamous partnership (3) (5).
The breeding period of the star finch extends throughout the year, although eggs are usually recorded between February and May (3), or in some locations between February and October, or even as early as December (2). The star finch constructs a globular or bottle-shaped nest out of grass, and the nest may be located in a shrub or tree, or among grass, sedges or reeds. The female star finch usually lays a clutch of 3 to 6 eggs, or sometimes up to 7, which both sexes take turns to incubate for roughly 12 to 13 days (2) (3) (5).
The young star finches leave the nest after about 17 days, but are fed by the adult birds for a further 2 or 3 weeks before they become independent (2) (3). The adults are then likely to lay a second clutch of eggs, whether or not the first is successful. The star finch can start breeding in its first year after hatching, and individuals may live for up to four to six years in the wild (3).
The specific movements of the star finch are largely unknown, but it is believed to be sedentary, with only small amounts of local dispersal at the end of the breeding season (3) (4). The star finch often forages in flocks of around 10 to 20 birds (2) (5), constantly calling to stay in contact (2). However, outside of the breeding season it may form larger flocks of up to 500 individuals (5), sometimes in company with other finch species (2).