Frequency of the white phase of the southern giant petrel, Macronectes giganteus (Gmelin)

Abstract

Published data on frequencies of white-phase M. giganteus in breeding colonies and at sea are reviewed and compared with observations made at colonies on Macquarie I. and at three locations in Antarctica. The frequency of white birds in the single east-coast colony on Macquarie I. (1 5.1 %) was significantly higher than that in west-coast colonies (6.8 %) while that in Antarctic colonies was very low (0.3 %). No relationship could be shown between plumage-phase frequency in breeding colonies and either their latitude or their position relative to the Antarctic Convergence. Several suggestions for the control of plumage-phase frequency are made.