Breeding Biology of the Gouldian Finch Erythrura gouldiae, an Endangered Finch of Northern Australia

Abstract

The breeding biology of the endangered Gouldian Finch Erythrura gouldiaewas studied at two sites in the Northern Territory over seven breeding seasons. Clutch size was 5.2 ± 1.3; 4.8 ± 1.5 nestlings fledged from successful nests. Clutch size had no influence on egg survival. At least one egg hatched in 50% of nests and 75% of nests fledged at least one young. Nesting success varied between years, sites and method used to calculate it: Newry 42-56%; Yinberrie 32-48%. Annual productivity (based on nesting success) was 1.5 fledglings per bird per season. Egg laying occurred from January to August, depending on the wet season and up to three clutches were recorded in a season. Only 15-16% of breeding adults bred at the sites in a subsequent year. Usually, pair bonds were maintained within a season and sometimes the same hollows were re-used. Over four years 18-25% of nesting hollows were sealed by termites. Some hollows were more attractive to birds than others across years. Trees containing nests were clumped.