Two counts of skuas (Catharacta maccormicki) at Cape Hallett were made between 17 and 20 January 1983: in one 85 pairs and 83 non-breeding birds, total 253 birds; in the other, 83 pairs and 79 non-breeding birds, total 245 birds. South Polar Skua numbers remain low, suggesting a continuation of the 1960s decline or the influence of climatic factors such as heavy snowfall during critical stages of skua breeding.
Authors: R. Schodde, P. Fullagar and N. Hermes
Birds observed during landings on four islets of the
Western Chain, Snares Islands, in February 1984 are discussed.
A census of Salvin’s Mollymawk revealed 586 chicks on two of
the islets and one stack, and so the population is not likely to
exceed 650 pairs. The numbers of the eight other bird species
known to breed on the Western Chain were estimated, and their
distribution is described. Measurements of 20 chicks of Snares
Crested Penguin indicate that the breeding cycle on the Western
Chain is about six weeks later than on Main Island.
Buller’s Mollymawk, Mottled Petrel, Sooty Shearwater,
Scuthern Skua and Red-billed Gull are new breeding records for
the Western Chain, and eight other species observed had not
been reported previously.
The extinct subfossil eagle of the Chatham Islands is referable to the genus Haliaeetus rather than to Ichthyophaga wherein originally described. Haliaeetus australis, as it should now be known, is more similar to northern species of the genus, particularly H. pelagicus, than to the geographically closer species H. leucogaster, and its ancestors probably colonised the Chatham Islands from the Northern Hemisphere rather than from Australasia.