The observations carried out on Haswell Island on 20—24 January 1979 showed the occurrence of 7 species of nesting birds: Pygoscelis adeliae — about 36000 individuals including about 11300 young. Stercorarius skua maccormicki— 76 adults and 15 young, Daption capensis — 220+/- 10 nests, Fulmarlus glacialoides — 3150 +/- 200 nests, Thalassoica antarctica — 250 +/- 10 nests, Oceanites oceanicus — about 500 nests and Pagodroma nivea — about 10 nests. The time of hatching and moulting was found to be 15—20 days earlier, and the percentage of two-egg clutches in nests of Procellariidae was lower as compared with the literature data. More of the two-egg clutches were found for Stercorarius skua maccormicki. The krill dominated in the food of studied species of Procellariidae. Biometrical data for eggs of the majority of studied bird species were gathered.

The presence of 31 species of birds was observed at sea sout of 50°S, out of this number 26 species were present also south of 60°S. The most numerous aggregations of birds were recorded in the regions of: Elephant Island, the South Orkneys and NE part of Bransfield Strait. The average number of birds during 10-minute observation was 74.5. In the areas under observations Daption capense predominated quantitatively. The following species were subdominant: Pygoscelidae, Oceanites oceanicus, Diomedea melanophris, Fulmarus glacialoides and Macronectes giganieus. In the total number of the birds observed krill-eaters contributed in 80.1% plankton-eaters — 7.8%, squid-eaters — 6.2% omnivores — 5.9% and fish-eaters — 0.1%. In comparison with the autumnal observations more than twice as many birds at sea were observed in the same area.

Distribution and numbers of Lobodon carcinophagus and Leptonychotes weddelli were evaluated. Lobodon carcinophagus dominated on ice floes in offshore zone of Mirnyj Station and in regions of open pack ice close to the northern edge of ice fields. Leptonychotes weddelli dominated only on the shore-ice close to Leningradskaja Station in March 1979. A thesis of the lowered daily activity of Leptonychotes weddelli was confirmed by observations.

In the region under investigations 30 species of seabirds were observed. In the southern part of Drake Passage Daption capense. and Oceanites oceanicus predominated quantitatively, Macronectes giganteus, M. halli and Pachyptila spp. were subdominant. The vessel was often accompanied by Diomedea exulans. In the Bransfield Strait Fulmarus glacialoides, D. capense and O. oceanicus were predominant. M. giganteus was subdominant. The estimated value of the biomass of seabirds was the highest in the region to the west of Elephant Island, slightly lower in the region of Anvers Island, Smith Island and Livingston Island, and the lowest in the south-eastern part of Bransfield Strait and the middle part of the investigated region of Drake Passage.