The south-west of Western Australia has undergone recent and extensive clearing of its native vegetation to develop agricultural enterprises. In some areas, over 90% of the original vegetation has been removed and the remainder is scattered in numerous patches of varying size, shape, degrees of isolation and degradation. There have been marked changes in the distribution and abundance of the avifauna of this area, with some species disappearing from parts of their former range and others expanding their ranges to take advantage of the altered landscape. Carnaby's cockatoo Calyptorhynchus funereus latirostris is one species which has suffered widespread decline in numbers as a result of the fragmentation of its former habitat and it no longer occurs over a significant portion of its former range. The extensive removal of native vegetation, patchy distribution of food and interactions with species like the galah Cacatua roseicapilla and man are contributory factors to its decline. It is pointed out that some local disappearances of this species may have been avoided if corridors of native vegetation had been left across the landscape to link remnant patches. These could have channelled Carnaby's cockatoo to areas of native vegetation which provide its food. Not only is it important to retain linkages between remnants of native vegetation but there is a need to re-establish corridors of native vegetation in extensively cleared agricultural areas such as those in the wheatbelt of Western Australia.