Fluctuations in the population of southern elephant seals <i>Mirounga leonina</i> at Kerguelen Island

Abstract

An analysis of census information published for the years 1952, 1958,1960 and 1970 and that obtained during this study in 1977, indicates that both the breeding bull and cow components of this population fluctuated in numbers during the past 25 years. In spite of these fluctuations, the general trend for the cow component was to increase at a rate of 1,4% per year, while the bull component decreased at a rate of 1,9% per year. An analysis based on subdivisions of the study area into distinct regions indicated that the range of fluctuation increased as mean density increased. The population is regarded as a stable fluctuating population and the influence of environmental and social factors on the observed population trends is discussed.