Habitat use, temporal activity patterns and foraging behaviour of raptors in the south-west of the Northern Territory, Australia

Abstract

On the basis of opportunistic observations, the preferred habitats of diurnal raptors in the south-west of the Northern Territory are quantified in terms of their vegetation structures and composition, and linked with foraging methods and information on local diets. Broad interspecific differences in diel activity patterns are also described. The evidence suggests that raptor species in this part of arid Australia differ with respect to their foraging times, habitats and methods, and that these differences relate to their partitioning of food resources.

An intraspecific and interspecific comparison of raptor diets in the south-west of the Northern Territory, Australia

“…The region is hot, arid and very thinly populated by humans: much of it is sandplain with hummock grassland or sparse shrubland (Aumann 2001a). Woodland is restricted to scattered stands of a few square kilometres or less, except for some tracts of desert oak (Allocasuarina decaisneana) and the river red gums (Eucalyptus camaldulensis) lining the creeks.…”

“…The main purpose of the study was to quantify the food resources of raptors in the south-west of the Northern Territory, Australia, as a pre-requisite to a broader exploration of the importance of resource availability in the structuring of the raptor assemblages there (Aumann 2001a(Aumann , 2001b(Aumann , 2001c. The diets of several raptor species have been determined in the east and south-east of Australia (Marchant and Higgins 1993;Olsen 1995), but in the arid inland only that of the wedge-tailed eagle (Aquila audax) has been a focus of significant research (Leopold and Wolfe 1970;Brooker and Ridpath 1980).…”

Resource pulses and mammalian dynamics: conceptual models for hummock grasslands and other Australian desert habitats

“…The population dynamics and diets of avian and larger mammalian predators such as the dingo ( Canis lupus dingo ), red fox ( Vulpes vulpes ) and cat ( Felis catus ), appear to be influenced strongly by the abundance of smaller mammals and thus, indirectly, by rainfall‐driven pulses of productivity (Plomley, 1972; Morton et al , 1977; Morton & Martin, 1979; Corbett & Newsome, 1987; Newsome et al , 1989; Thomson, 1992; Pople et al , 2000; Aumann, 2001; Read & Bowen, 2001; Paltridge, 2002; Pavey et al , 2008). These increases probably reflect both successful recruitment and migration (Aumann, 2001). During periods of low rainfall, when populations of small mammals decrease, predators undergo reductions in abundance (Newsome & Corbett, 1975; Pople et al , 2000; Aumann, 2001) and often switch their diets to other taxa, particularly reptiles (Paltridge, 2002).…”

“…These increases probably reflect both successful recruitment and migration (Aumann, 2001). During periods of low rainfall, when populations of small mammals decrease, predators undergo reductions in abundance (Newsome & Corbett, 1975; Pople et al , 2000; Aumann, 2001) and often switch their diets to other taxa, particularly reptiles (Paltridge, 2002).…”

Observations of hunting attacks by the Powerful Owl Ninox strenua and an examination of search and attack techniques

“…Seven major search techniques used by birds of prey have been defined by various authors (Fox 1977;Baker-Gabb 1984;Aumann 2001;Olsen et al 2006;Olsen 2014): stillhunting (or perch-hunting), fast contour-hugging flight, soaring and prospecting, slow quartering, stalking on the ground, listening and flushing from cover.…”