abstract
On Marion and Prince Edward Islands, southern elephant seals occurred mainly on the leeward east and north coasts between 1973 and 1977. During the spring breeding haul-out, adults and pups remained on beached scattered along these coasts. During the summer and autumn moult haul-out, adult and subadults arrived on the beaches and then moved inland into moulting areas, while moulting yearling remained on the beaches. Moulting area also occurred mainly on the leeward coasts, though their distribution differed slightly to that of the breeding beaches. The distribution of elephant seals during the breeding and moulting phases of the summer haul-out season therefore differed both vertically and horizontally. Pup counts totalled 1 115 and 386 on Marion and Prince Edward Islands respectively, indicating a 69,5 per cent decline in population size on Marion Island between 1951 and 1976. Competition with man for fish in winter feeding grounds, predation by killer whales at the islands and competition for food resources with fur seals, are considered to have led to the population decline.
