Falco hypoleucos is infrequently seen over much of arid and semi-arid Australia. Its range covers eastern Australia, especially arid regions, and northern Australia south to approximately 26oS, south of which it is casual in occurrence (Johnstone and Storr 1998). It may have been eliminated from some breeding areas early in the 20th century, particularly those with more than 500 mm annual rainfall in New South Wales, where its eastern limit has also shifted further inland since the 1950s (Olsen 1998). The contraction in its breeding distribution (Garnett 1993) is attributed to habitat degradation, which reduced the suitability of some semi-arid habitat and restricted the species to the arid zone (Olsen 1998). The main breeding distribution now covers areas where annual rainfall is <500 mm (Garnett et al. 2011). The present range is believed to be stable, and it is apparently more widespread during inland droughts. There is evidence of regular seasonal movements between the arid zone and northern Australia, and possibly New Guinea, and from west to east in Queensland. It is always found at very low densities, and its population is believed to number only 1,000 mature individuals in total (Schoenjahn 2011, Garnett et al. 2011). These estimates are based on limited information about the species and comparison with data for the Peregrine Falcon Falco peregrinus (J. Schoenjahn in litt. 2007). The population of F. hypoleucos is thought to be stable.