Spending the vast majority of their lives far our at sea, southern Elephant seals haulout on land at regular intervals. As immatures they alternate between a spring or summer moult haulout and a winter haulout of unknown purpose. As adults they alternate between a spring breeding haulout and a summer or autumn moult haulout. They do not feed while on land, but rely on their blubber for energy (2) (6).
Breeding takes place from late August to late November each year. At this time adult southern elephant seals return from the open ocean to their breeding grounds to give birth and mate. Males arrive before the pregnant females and wait for their arrival, when the females collect together into groups known as ‘harems’. Access to females within a group is dominated by a single male, known as a ‘beachmaster’, but in very large harems, one or more sub-dominant males may gain access to females. Competition amongst males is intense, with fighting, vocalizing and impressive displays taking place. The females give birth to a single pup, two to five days after arriving on the breeding grounds. The pups are nursed for around 23 days, but several days before weaning their pups, the females are mated by the dominant male. Once the pup is weaned, the females return to the sea leaving the pups to fend for themselves. The pups remain ashore or in the shallows for four to six weeks before leaving the beaches for the ocean (2) (6).
Between November and April, the southern elephant seal will again haul itself out onto beaches to molt (5). Molting, during which these enormous mammals gain new skin and hair, can take three to five weeks (2).
Southern elephant seals are remarkable divers, with dives deeper than 2,133 metres and as long as 120 minutes recorded (7) (8). They spend 70 to 80 percent of their lives below the sea surface (8). Southern elephant seals are thought to feed primarily on squid, but also fish, crustaceans, and ascidians. At sea they are found between the Subantarctic Front and the pack ice, with males moving further south than females (1).