New records of southern elephant sealsMirounga leoninaL. on the coast of southern Africa

Abstract

Systematic recording of elephant-seal sightings, including 92 hitherto unpublished records, has increased the number of records on the coast of southern Africa to 130. The data set is now the largest on record for any southern continent other than Antarctica. It provides an opportunity to examine the biological significance of such matters as seasonality, possible causes of haul-out, their possible origins and implications for interpretation of elephant-seal dispersal around their breeding colonies. The number of sightings has increased recently. The overall sex ratio is 52,4 per cent male to 21 per cent female, 26,6 per cent being of indeterminate sex. The seals haul out mainly from November to February, and indications are that males and females disperse straight after the breeding season and a few months later reach the coast of southern Africa. The most likely primary cause of haul-out for immature seals is to moult. It is postulated that the seals originated mainly from South Georgia. It is not clear if the seals recorded are true vagrants or the outer fringe of a normal dispersal. Of the sightings, 24 were tagged after arrival, and of these, 13 were sighted more than once and 6 showed a regular pattern of movement. There were 19 sightings of elephant seals at local fur-seal rookeries and, with one exception, the two species co-existed peacefully. There are three confirmed and two unconfirmed births on the coast. The ability to develop a preference for unfamiliar places and to pup outside their natal colonies could explain how they colonize new areas.