A population of Sulphur-crested Cockatoo Cacatua galerita at Ashfield, New South Wales, was observed
over a four year period. The birds were intentionally habituated to human observers and contact with humans
was positively reinforced. The habituation process allowed behaviour patterns to be observed at distances of
0.5-3 m which is closer than other studies on free-ranging Sulphur-crested Cockatoos. Five previously undescribed
behaviour patterns were noted - pair beak-clacking, posing, male/male beak-clacking, male/male allopreening
and chorusing. The courtship display differed strikingly from previous descriptions. Other observed behaviour
patterns were similar to previous descriptions for Cacatua species.
