Southern Elephant Seal - Seals.scar.org

Southern Elephant Seal
Mirounga leonina
Photo:A.S. Blix
The genus name is from the Australian aboriginal name for this seal and
the species name from the Latin for “lion” (leoninus), perhaps referring to
the roarlike threat call of breeding males. Southern elephant seals are
massive as adults and indeed are the largest pinnipeds in the world. Adult
males may reach 5 m long and up to 5000 kg in body mass. They
have relatively short, broad heads and large, forward-looking eyes. Adult

males have slightly enlongated noses, though far less exaggerated than
those of the species’ closest relative, the northern elephant seal (M.
angustirostris). The pelage is light to dark brown dorsally and lighter
brown to yellow ventrally, but always lighter ventrally. Pups are born
with a longer black pelage which is shed just after weaning and replaced
by adult-like hair. Females give birth in September and October, nurse
the single pup for about three weeks and then are mated. They then go to
sea to feed for about two months before returning ashore for about three
weeks to molt in December and January, and then return to sea to forage
for another eight months. Adult males fast while ashore for two to three
months, from August through November, and then return to sea to forage
before returning to land to molt in February and March. They then return
to sea several weeks later and forage for another five to six months.
Southern elephant seals are deep divers, feeding mostly at depths of 400
m to 600 m, and occasionally as deep as 2000 m. Their diet is mostly
deep-water squid and lantern-fishes. When foraging they range over
great distances in the southern ocean, principally focusing their activity
at ocean current boundaries, near seamounts and upwelling areas along
the Antarctic contintent. Virtually all of their breeding colonies are on
sub-Antarctic islands, except the largest at South Georgia which is just
within the Antarctic Convergence boundary. There are, however,

small colonies on islands along the western edge of the Antarctic
Peninsula and a robust and growing colony on the coast of Argentina.
Colonies in the Indian Ocean sector of the Antarctic declined by about
80% from the 1960s through the early 1990s and may have stabilized
since. The cause(s) of the decline is unknown but thought to be related
to variable and reduced prey abundance having effects on
juvenile and adult female survival.