The Ecology and Breeding Biology of the Red-winged Fairy-wren Malurus elegans

In 33.5 ha of Kam forest in Smith's Brook Reserve, 841 individually colour-banded Malurus elegans, a Western Australian endemic, were studled from 1980-1986 in 24-30 territorial groups. This species is multi-brooded but less so than other Malurus due to their short breeding season; 90% of eggs were laid in October and November. Most nests (85%) were within 300 mm of the ground and more than half in accumulated litter on the forest floor, nest sites liable to be lost following fuel-reduction burning. Clutches of two and three were equally common (mean = 2.43 eggs); fertility was 94%; incubation lasted 14-15 days; nestlings hatched synchronously and fledged 11-12 days later, juveniles were independent of adult provisioning when one month old. Parasitism by cuckoos was rare and predation variable between years. Of eggs laid, 79% hatched and 52% produced fledglings. Repeat nesting was rapid and groups produced an average of 2.5 fledglings and 1.9 independent young per year. M. elegans are co-operative breeders; 82% of groups had helpers, the mean size being four adults. Both adult and juvende survival were high and the limited forest habitat was fully occupied.