SUMMARYCrome, F. H. J. 1975. Some observations on the biology of the Cassowary in northern Queensland. Emu 76: 8–14.The CassowaryCasuarius casuariusand its diet were studied in the Lacey's Creek—Clump Point area of northern Queensland. Birds are usually solitary and territorial, females apparently dominant over males. Males incubate and rear the chicks. Females may mate with more than one male during the year. Some agonistic and sexual displays are described. Development of chicks is briefly outlined. The birds take three years to develop full adult plumage. Cassowaries eat fruit of over sixty-seven species. The family Lauraceae is most important. The breeding season, June to October, corresponds with the time of maximum abundance of fruit in the forest.