Abstract
Summary: Field work by the author on petrels began in 1936 and finished in 1957, many of the results of which have already been published. The Mottled Petrel was not studied in detail, as were the other species concerned, and this paper brings together those observations which were made on the Mottled Petrel and compares them with the other species studied. In the main the timing of the breeding season and the breeding behaviour of the Mottled Petrel appear to be much the same as for the Sooty Shearwater.