Breeding biology of raptors in the south-west of the Northern Territory, Australia

During 1995–97, reproductive requirements and success were quantified for raptor assemblages of up to 10 species on (usually dry) creeks in the south-west of the Northern Territory. Most breeders chose to nest in River Red Gums (E. camaldulensis) that were taller, of greater girth and more foliated than other trees generally available on the local drainages, but few interspecific differences in nest tree or nest site requirements were identified. Breeding densities and success fluctuated greatly during the study. Total assemblage productivity in 1996, a drought year, was 6–10 times lower than in 1995 and 8–15 times lower than in 1997. Declines in territory occupancy, breeding density, breeding success and the number of young fledged per active nest were characteristic responses to the drought for most species.