Abstract
The conservation requirements of the isolated population of the red-tailed black-cockatoo C. magnificus in southeastern South Australia and southwestern Victoria were studied. The range and status of the population was clarified and earlier suggestions of the population''s dependence on brown stringybark, Eucalyptus baxteri was confirmed. An additional food source, bulloak, Casuarina luehmannii, was reported. The population''s breeding requirements are still poorly known. Clearing of E. baxteri is the main threat to the population''s existence.