Department of Internal Affairs

In September 1978 a colony of about 30-35 pairs of South Georgian Diving Petrels (Pelecanoides georgicus) was identified breeding among the sand dunes at Sealers’ Bay, Codfish Island, New Zealand (46° 46′ S, 167° 39′ E). This may be the only surviving colony of this species in the Australasian region. It is of considerable interest, furthermore, in being the only colony situated on the Subtropical Convergence (all others are in colder waters) and in being the only one sympatric with P. urinatrix chathamensis (all others are sympatric with P. u. exsul).

During 1970, 2,152 kilometres of coast were patrolled by 82 persons. 4,613 dead seabirds, including high numbers of Lesser Broad-billed Prions (Pachyptila salvini), were found. During 1971, 2,470 kilometres of beach were patrolled by 148 persons. 6,244 dead seabirds, including high numbers of Fairy Prions (P. turtur),were found. During 1972, 2,748 kilometres of beach were patrolled by 117 persons. 4,046 dead seabirds were found but there were no major wrecks. During the three years there were new beach patrol records of Soft-plumaged Petrel (Pterodroma mollis), Fulmar Prion (Pachyptila crassirostris) , Brown Booby (Sula leucogaster), Lesser Frigate Bird (Fregata ariel) and Antarctic Skua (Stercorarius skua maccormicki). The single specimen of Manx Shearwater (Puffinus puffinus) is a new record for New Zealand.

Between 8 November and 4 December 1978 observations were made on Southern Great Skuas (Stercorarius skua lonnbergi) at Antipodes Island in the Southern Ocean. Their food habits were determined by observing birds and identifying prey remains. Penguin eggs and chicks were the dominant prey of coastal skuas, whereas those with inland territories relied on petrels and shearwaters. Clutch size in 11 nests averaged 1.8 eggs; most eggs in nine study nests hatched during the first fortnight of November. Hatching success was 54%, but only 3 of 10 chicks survived until 4 December. At that stage of the breeding season, and allowing for unnatural losses of eggs and chicks, productivity was 0.5 chicks per breeding pair. Six chicks were weighed and measured for 5-20 days. Hatching weight averaged 74.3 g. Initial weight gains were small, but after day 4 the average growth rate was 31.6 g/day. Chicks which were heavier at hatching remained so subsequently. Mean bill length at hatching was 17.8 mm and mean depth 9.9 mm. Little growth occurred for the first five days, but afterwards the average growth rate was 1.0 mm/day for bill length and 0.4 mm/day for bill depth. The ratio of bill length to depth changed during growth, and attained the adult condition by age 17-20 days. There were no consistent differences between chicks from coastal and inland nests in their weight gains, or in the growth of their bills.

Abstract Filoplumes occur on the head and neck of most dark‐crowned procellariiform birds, but do not seem to have been reported before. Their pattern of distribution is apparently related to the bird's feeding habit. The filoplumes, many of which project beyond the feathers, are more abundant in breeders than in fledgelings, and in males than in females. Their value in sexing birds before egg‐laying was compared with that of culmen lengths, bill widths and body weights, by using data from Grey‐faced Petrels (Pterodroma macroptera gouldi) on Whale Island, Bay of Plenty, and sexual dimorphism was demonstrated.