Patterns of Movement in the Western Long-billed Corella Cacatua pastinator in the South-west of Western Australia

Abstract

: Observations of individually marked Western Long-billed Corellas Cacatua pastinator in a breeding area at Burakin in the central wheatbelt of Western Australia indi- cated that there were three phases of movement patterns. The juvenile phase started with fledging; the young and their parents moved to an area with food, water and shelter in close proximity where they were joined by other family groups and immature birds. Two to three weeks later, the families and immature birds moved to Dalwallinu, 55 km to the north-west, where they joined up with birds from other breeding districts, returning to the breeding districts between January and March. The immature phase from independence at three to four months lasted until the birds started breeding; immatures returned to Dalwallinu each summer and spent the rest of the year in a breeding district as part of a locally nomadic flock that moved over an area of about 250 km2; some dispersal to breeding areas other than their natal area may occur during this phase. The adult phase included the annual movements with offspring (if any) to Dalwallinu and back. For the rest of the year, the nest area was the focal point of a pair's activities. Foraging distance of breeding birds declined during the winter and was at a minimum when they were incubating and feeding nestlings. Breeding adults were strongly philopatric and strongly bonded so that except when incubating or feeding, the partners of a pair were rarely separated. The summer movement to a common feeding area was observed also in two other populations and its origins are discussed. Comparisons with the movements of other cockatoos in the wheatbelt are made.