The leopard seal is famed for its prowess as a hunter, taking more warm-blooded prey than any other pinniped (2) (6). Being cumbersome on land, it typically only hunts in the water, with penguins and even other seals habitually falling prey to its stealthy attacks (2) (3) (6). However, somewhat contrary to its fearsome reputation, krill actually takes up the largest proportion of the leopard seal’s diet (up to 50 percent), particularly during the winter months when other food sources are scarce (2) (3). Indeed, predation on penguins in the vicinity of the rookeries is seasonal and appears to be the preserve of a relatively small number of seals, with most preferring to forage further out to sea (6) (8). In addition to krill, penguins and seals, a range of other food items feature prominently in its diet, including fish, squid, other seabirds, and occasionally the carcasses of whales (1) (3) (4) (6).
The leopard seal is a solitary species, both at sea and on the ice, with groups only ever being formed by temporary mating pairs and by mother and pup pairs (1) (3). Mating occurs during the height of the Austral summer, with birthing taking place between early October and January (1) (2). Each mother gives birth to single pup, which is weaned on the ice floes of the pack-ice for around a month (2) (3) (7). Sexual maturity is reached when the seals are around four to five years old, slightly later in males, and longevity in the wild is estimated to be over 26 years (1) (6).
Little is known about the seasonal movements of the leopard seal, but periodic northwards movements do occur, probably in response to changes in the availability of food and the location of the pack ice. Typically, the mature adults remain around the pack ice year round, while the younger juveniles venture into the sub-Antarctic between June and October (3).