This seal is the second largest (after the southern elephant seal) to be found in the Antarctic ocean. Its only predator is the Orca. It has a wide ranging diet, which includes cephalopods, other pinnipeds (i.e. seals and similar) krill, fish and birds with a specific interest in penguins.
It was first scientifically described in 1820. While naturally found only around Antarctic, they have been noted to wander as far as New Zealand and Australia. Except pups with their mother, they live solitary lives, and are thought to number 220,000 to 440,000.
Being large hunters, they can pose danger to humans, though attacks on humans are rare.
They live for up to 26 years, and are thought currently relatively stable as a species, though their reliance on the ice floes around Antarctica may prove a threat to the species if climate change continues unabated for some time further.