Southern elephant male seals (Mirounga leonina Linnaeus, 1758) were studied at King George Island (62°14´S, 58°40´W) from September to December 1999. The first males came ashore at the beginning of September. Twenty-five adults were immobilized, hot iron branded, and measured. Thirteen out of the 25 marked males spent an average of 66 (+/-8) days on land. Early arrival was positively correlated with the time spent ashore (r = 0.88, P < 0.05). Nine harems were formed in the study area. At the maximum haul-out of females (28 October) mean harem size was 32ą42 females (range 3–107). During the course of harem development, 10 changes in male harem dominance were observed. These changes were more frequent during the early (1–20 October, n = 6) than during the mid (21 October – 10 November, n = 2) and late (11–29 November, n = 2) periods of harem development. Overall, there were 14 dominant males; five of these in two different harems and nine in one harem. Of the 25 marked males, 44% were resighted in the following breeding or moulting season, and 16% seemed to improve their potential breeding success.
A population survey of southern elephant seals (Mirounga leonina Linnaeus, 1758) was conducted at Nelson Island, South Shetland Islands, Antarctica, during the 2001 breeding season. Two breeding sites were identified, one of which had not been previously reported. The largest breeding site was located at Duthoit Point, with a total of 128 females, 111 pups and 7 weanlings distributed in 6 harems along 3 km of coast. The new breeding group was observed at Harmony Point, where 3 females with their pups were found. This is the first report on southern elephant seal numbers during the breeding period for the Nelson Island coast.
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.