The pinnipeds were counted on the western shore of Admiralty Bay during 1994. It was found that the numbers of one breeding species Mirounga leonina is stable, the remaining four species show a variable pattern of occurrence. However, there is no evidence to detect any trend since 1988.
Throughout 1978 regular counts of pinniped mammals were conducted along as 12-kilometre-long stretch of the Admiralty Bay coasts. The occurrence of all the six species of antarctic seals was noted, among them the most numerous were Mirounga leonina, Arctocephalus tropicalis and Lobodon carcinophagus. The number of these animals varied within a year-cycle. M. leonina and Leptonychotes weddelli breed at Admiralty Bay.
Heartbeat and respiration of southern elephant seals (Mirounga leonina), Weddell seals (Leptonychotes weddellii) and Antarctic fur seals (Arctocephalus gazella) were monitored simultaneously using a visual and non-intrusive method, at King George Island, South Shetland Islands. All three species demonstrated sleep apnoea with reduced heart rate. In adult elephant seals, heartbeat fell 18% in apnoea; spells lasted up to nine min, usually ending in disturbance from conspecifics or human visitors. Slight human disturbance (notably slight noise) reduced time spent in apnoea from over 40% to 4%, significantly reducing the frequency of falling into apnoea and increasing mean heartbeat. Further disturbance resulted in head raising, aggression, scratching, rolling and movement away. The visual monitoring of heartbeat and respiration can be used with resting or slightly disturbed animals but not when major body movements occur.
The paper presents the results of seven-year survey of Antarctic seals along the western shore of Admiralty Bay, King George Island, South Shetland Islands. Five species were monitored during seven of the eight years, between 1988-95, excluding 1993. Numbers of elephant seals and Antarctic fur seals showed strong annual cycles, fur seals with two seasonal peaks. These of the other three species were more irregular. Fewer Weddell seals were seen in 1994 and 1995 then during the period 1988-92; with this exception, no overall trend in numbers was apparent during the period 1988-95.
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.