Status of southern elephant seals at South Georgia

Abstract

Approximately 54% of the world population of southern elephant seals (Mirounga leonina) breeds at South Georgia. A partial survey in 1951 and a complete survey in 1985, together with counts at specific sites between these times, suggested that the population (around 100 000 breeding females) had not changed significantly in 34 years. This was in contrast to marked declines in most other populations. To examine this further, we conducted a third survey in 1995. This produced an estimate of 113 444 (se = 4902) breeding females. Taking into account improved information about the behaviour of female elephant seals since the survey in 1985, there was no significant change in the number of breeding female elephant seals between 1985 and 1995. When combined with information from the 1951 survey, this supports the view that the total population size has not changed significantly during the past 45 years. Evidence for regulation of the population by environmental factors is equivocal. We hypothesize that the lack of any net change in population size may be linked to a limited availability of high quality breeding habitat.