Flying bird counts were carried out at Esperanza Bay (62°24'S, 56°59'W), Antarctic Peninsula, between November 1989 and February 1990. Six breeding species (Oceanites oceanicus, Chionis alba, Catharacta lonnbergi, Catharacta maccormicki, Larus dominicanus and Sterna vittata) and six visitor species (Macronectes giganteus, Fulmarus glacialoides, Daption capense, Pagodroma nivea, Fregetta tropica and Phalacrocorax atriceps) were recorded. Kelp gull and Antarctic tern populations have decreased in relation to the data by previous authors, perhaps as a result of the increased activity at Esperanza Station. Cygnus melanocoryphus was recorded for the first time at Esperanza Bay.

The diet of the unsexed breeding Adélie penguin (Pygoscelis adeliae Hombron et Jacquinot, 1841) was investigated during three consecutive chick rearing periods, from 1996–97 to 1998–99, on Laurie Island, South Orkney Islands (60°46’S, 44°42’W), Antarctica. This analysis showed that during the whole sampling period, Antarctic krill (Euphausia superba Dana, 1852) represented the predominant prey in terms of frequency of occurrence, mass, and number. The hyperiid amphipod Themisto gaudichaudii (Guerin-Méneville, 1825) was present in small amounts. Electrona antarctica (Gunter, 1878), Trematomus newnesi (Boulenger, 1902) and larval stages of Nototheniidae constituted the bulk of the fish portion, particularly during the 1997/98 and 1998/99 breeding periods. This study is the first examination of the Adélie penguin diet at Laurie Island. It is important to recognize, however, the importance of knowing the sex of the penguins being sampled and that prey composition may vary during the breeding season and from one year to the next.

A serological study to detect antibodies against microbes in avian mycoplasmosis (Mycoplasma gallisepticum and M. synoviae), and salmonellosis (Salmonella gallinarum and S. pullorum) was carried out. A hundred and twelve Antarctic birds (42 Adelie penguins, Pygoscelis adeliae, 30 southern giant petrels, Macronectes giganteus and 40 skuas, Catharacta antarctica and C. maccormicki) from King George Island, the South Shetland Islands, and Laurie Island, the South Orkney Islands in Antarctica were studied. The serological test used in this study was a rapid agglutination test. According to the results and considering the number of samples analysed, it is reasonable to believe that Adelie penguins, southern giant petrels, and skuas populations of the areas mentioned above are free from mycoplasmosis and salmonellosis.

A survey of breeding birds was carried out during the summer 1997-98 in several localities of the northern Danco Coast, Antarctic Peninsula. A total of 10 species were recorded: Pygoscelis antarctica (3234 pairs), P. papua (1888), Macronectes giganteus (76), Daption capense (61), Oceanites oceanicus (104), Phalacrocorax bransfieldensis (92), Ononis alba (15), Catharacta maccormicki (168), Lams dominicanus (583) and Sterna vittata (160 pairs).

The cephalopod diet of the gentoo penguin, Pygoscelis papua and the Antarctic fur seal, Arctocephalus gazella was comparatively analyzed at Laurie Island, South Orkney Islands. A total of 125 stomach samples were collected by the water off-loading method from gentoo penguins during the autumns of 1993, 1995 and 1996, and 39 fur seal scats were collected from mid March to April 1988. Cephalopods preyed upon by gentoo penguins were represented by 1974 beaks (1628 lower, 346 upper) which occurred in 50.4% of the samples. Lower beaks identified belonged exclusively to the squid Psychroteuthis glacialis. The mean lower rostral length (LRL) of these beaks was 1.1 mm (range 0.4– 1.8 mm). From the Antarctic fur seal scats 103 beaks (41 lower, 62 upper) were removed from 60.6% of scats which contained prey remains. The cephalopod species identified were Slosarczykovia circumantarctica and P. glacialis which constituted 78.8% and 21.1% in terms of numbers, respectively. The mean lower rostral length for S. circumantarctica was 2.7 mm (range 2.0–3.5 mm), while that of P. glacialis was 1.6 mm (range 1.0–2.5 mm). The foraging behaviour of the two top predators was analyzed and discussed according to the composition and size of their cephalopod prey.