This publication covers data collected during the period 1900-1976. About 10% of the records are based on the literature, the remaining 90% on observations made since 1960.
The earliest data was collected for the Atlas Project of the Bird Observors' Association of Tasmania (B.O.A.T.). This started as a personal venture of the author and grew, after incorporation with the Royal Australasian Ornithologists Union Atlas scheme, into a comprehensive collection of distribution maps for 138 species.