Southern Elephant Seal
Environmental Research Unit, PO Box 434, Stanley, Falkland Islands
SOUTHERN ELEPHANT SEALSMirounga leonina
Breeding Range: Subantarctic Islands and South America
Length: Males: 6m, Females: 3m
Weight: Males: 4,500kg, Females: 900kg
Falklands Population: 600 breeding females
World Population: ~200,000 breeding females
The Falklands population is now almost entirely concentrated at Sea Lion Island, in the south of the archipelago. Preferred breeding sites are sandy or shingle beaches. Bulls begin establishing territories in early September. Females arrive late September and form into harems of up to 50 cows, under the domination of one bull. Pups are born from late September to late October, and the females mate shortly after pupping. The female remains ashore to suckle the pup for just 3 weeks, after which she weans the pup and goes to sea to feed. The pups remain ashore for up to two months without feeding, until hunger draws them out to sea in search of food.
Most cows and bulls have left the breeding site by late November, but yearlings and non-breeders begin arriving to undergo their annual moult. Breeding females return to moult during January to March, and bulls during March and April. Most adults remain at sea during the winter months. Diet comprises of squid and fish, much of which is taken during dives of up to 2 hours, reaching depths of over 700m. Elephant Seals rarely live much beyond 20 years of age, but females can begin breeding at just 3 years.
The Falkland Islands Elephant Seal population has undergone a rapid population decline from around 6,000 breeding females in 1992, to around 600 breeding females in 2002. The breeding sites which were once scattered around the Falklands have all been virtually abandoned, with the exception of Sea Lion Island. The full explanation for this is uncertain, but reduction of fish and squid stocks by commercial fishing fleets is almost certainly a factor.