As krill is a very abundant food source, there is a large population of these seals. Crabeater seals have specially adapted teeth with extra projections, so that when they gulp in seawater they can strain out the krill. Leopard seals Female leopard seals give birth to a pup on the sea-ice each season, and then return to the ocean to feed. Like the crabeater seals, leopard seals have unusual teeth for straining krill. They supplement their diet of krill by eating seal pups and penguins.
Leopard seals have very individual tastes.
Some remain near penguin colonies and eat the penguins they catch there while others prefer to eat crabeater seal pups. Other leopard seals prefer a sub-antarctic menu and migrate north to Heard Island to feed on penguin and seal pups there. Elephant seals are big and cumbersome on land, but they are superb swimmers and divers. Biologists have recorded them diving up to 2km deep and holding their breath under water for up to 2 hours. Elephant seals are able to accomplish these amazing diving feats because they have evolved some special adaptations, by which they conserve energy very economically.