Breeding biology and diet of the Wedge-tailed Eagle 'Aquila audax' in the New England Region of New South Wales

Abstract

The breeding biology, behaviour and diet of the Wedge-tailed Eagle Aquila audax were studied by 156 hours of observation from nest-renovation to the post-fledging period, and by analysis of prey remains and pellets, at one nest in the New England region of northern New South Wales in 2005. Supplementary observations and collections of food remains were made at three and two other nests, respectively. Egg-laying occurred in June (n = 5 clutches). At one nest, incubation (by both sexes) lasted 43±2 days, the nestling period lasted 90 days to first flight from the nest-tree (with the young venturing to branches in the nest-tree from 78 days), and the post-fledging dependence period lasted 4 months. Sexroles, parental behaviour and time-budgets in each phase are described and quantified, and juvenile growth and behavioural development are described. Fledgling productivity was 1.2 young per pair (1.8 per successful pair) in 2005 (n = 6 pairs), and 0.8 young per pair per year in 2005–06 (n = 12 pair-years). The breeding diet at two nests near Armidale (on the Northern Tablelands of New South Wales) in 2005 was 74% mammals (56% Rabbits 'Oryctolagus cuniculus'), 22% birds and 4% reptiles by number, and 89% mammals (40% Rabbits), 11% birds and <1% reptiles by biomass (n = 49 prey items). Hunting and attack behaviour are described; 80% of 10 observed strikes by experienced breeding adults were successful.