abstract
The Northern (Macronectes halli) and Southern (M. giganteus) Giant-petrels nest at islands between the Subtropical Convergence and the Antarctic continent, their breeding ranges overlapping at some islands near the Antarctic Convergence. Differences between the species include date of onset of laying, type of nest-site, and coloration of plumage and bill-tip. A review of the literature suggested that populations nesting at islands in the South Atlantic Ocean north of the Antarctic Convergence do not conform to either species. New observations from Gough Island in October and November 1973 support this suggestion and confirm that in some respects these birds combine the characteristics of both species. However, we need more information about the population of Giant-petrels at Gough Island and those at the other breeding stations in this region (Falkland Islands and Staten Island) before their taxonomic status can be assessed.
