DistributionRead full entry
Range DescriptionElanus scriptus occurs in the eastern arid zone of Australia but occasionally irrupts to all parts of the continent. The species is usually confined to the Coopers Creek drainage system (Olsen 1998), whilst its wider distribution is thought to be centred on the Barkly Tablelands in the eastern Northern Territory and river systems in south-western Queensland, north-eastern South Australia and north-western New South Wales (Garnett (Ed) 1993). Population cycles appear to be linked to those of the principal prey, the plague rat Rattus villossimus, which has population explosions following high rainfall (Olsen 1995). In years when rats are numerous the species can breed rapidly and be abundant. When rat populations crash following the onset of drought, birds are forced into areas that are outside their normal range and eventually most perish (Olsen 1995). These explosions in population and range rarely last for more than a year, after which the species's distribution again contracts (Garnett (Ed) 1993). Little is known about the intervening lean times when the species is rarely seen and the population may fall near to 1,000 individuals. Despite such fluctuations the species is regarded as secure (Garnett (Ed) 1993).