In previous centuries, Southern Elephant Seals were hunted for oil and their numbers dwindled dramatically. Populations have built up since hunting ceased but have declined again in recent years. The cause of the latest decline is unknown, but overfishing, coastal development and destructive tourism may be factors. Southern Elephant Seals are legally protected in extensive marine reserves and about 600 000 animals survive today.
Amazing Southern Elephant Seals
Southern Elephant Seals are the largest of the true seals. Like all members of this group, they have no external ears and their bodies are highly specialised for life in the water. Their limbs have evolved into flippers and their bodies are streamlined with thick fat layers for warmth and energy storage.
These seals spend most of the year at sea hunting prey in deep water. They swim by undulating their tail-like back limbs and can dive down hundreds of metres. When diving, their heart rate drops and blood flow is restricted to conserve oxygen. Dives usually last between 20 minutes and 2 hours before they surface to breathe and recover.
Adults leave the water twice a year, returning to well-known breeding colonies in September or November. The enormous males arrive first and fight among themselves to establish territories. Weighing up to 4000 kg, the males are fierce fighters, often covered in scars from past battles. Their size and their trunk-like noses are why they are known as elephant seals.
Female Southern Elephant Seals come ashore and join a ‘harem’ controlled by a dominant male. There they each give birth to a single 40 kg pup. The pups are completely black and feed on their mothers’ milk for about a month before she mates again and returns to sea. The pups remain onshore for another two months until they have reached 120 kg and grown a thick fur coat. Besides another month on land in January or February to moult, these seals are entirely aquatic.