Fur-seals & Sea Lions in South Australia

Fur-seals and sea-lions are pinnipeds – marine mammals with flippers. Worldwide there are many species of both groups but the following breed in South Australian waters:

• Australian Sea-lions – There are 39 breeding colonies on islands off the coast of South Australia. The largest colony is found at Dangerous Reef, followed by the Pages Islands and Seal Bay on Kangaroo Island, as well as Price Island, Pearson Island, Ward Island, Waldegrave Island, the Nuyts Archipelago, the St Francis Group of Islands and along the cliffs of the Great Australian Bight.
• Australian Fur-seals – 1 breeding colony has recently been established on North Casuarina Island, which lies off south-west Kangaroo Island. Other breeding colonies are found in Victoria and Tasmania.
• New Zealand Fur-seals – There are 18 breeding colonies on islands off the coast of South Australia. The largest is Neptune Islands, followed by colonies on Kangaroo Island, Liguanea Island, Pearson Isles, Ward Islands, Nicolas Baudin Island and Greenly Island.

The following species sometimes visit our shores:

• Leopard seals
• Southern Elephant Seals (frequent visitors to Kangaroo Island)
• Crabeater Seals
• Subantarctic Fur-seals
• Antarctic Fur-seals (one record in South Australia)
• Weddell Seals (one record in South Australia)
• Ross Seals (one record in South Australia)

The differences between Fur-seals and Sea-lions

All seals are pinnipeds (mammals with flippers). They are meat-eating mammals and they have the intelligence, learning abilities and play behaviours shown by other carnivores, like dogs and bears. There are three families of seals: the Otariidae (fur-seals and sea-lions), Phocidae (true or earless seals) and the Odobenidae (walruses).

Is it a sea lion or a seal?

There are several physical differences between seals (e.g. elephant seals) and sea-lions and fur-seals, but the simplest way to tell them apart is that sea-lions and fur-seals have external ears and true seals do not. Sea-lions and fur-seals also have two distinct hind limbs and walk on land whereas true slither along on their bellies on land.

Fur-seals vs sea-lions

The fur-seals and sea-lions that are found in South Australia can be difficult to tell apart. However, the species differ in size, coat colour and behavior. The most common species that people may come across are the Australian Sea-lion and New Zealand Fur-seal.

Australian Sea-lions are larger than New Zealand Fur-seals and are usually lighter in colour. Adult males (like Henry) are dark or chocolate brown with a creamy white mane extending from their eyes to the lower neck and shoulders. They develop their golden mane when they are about seven years old. Adult female sea-lions are silver-grey to brown with a creamy white chest, throat and sides of their face.

New Zealand Fur-seals have much pointier snouts compared to sea-lions and are have a more even colour. Adult male New Zealand Fur-seals are dark-grey to brown with a dark mane and paler fur around their muzzle. Adult females are dark-grey to brown with a slightly lighter chest and throat and darker belly.

Australian Sea-lion pups are chocolate brown when young but soon moult and can easily be confused with juveniles. New Zealand Fur-seal pups are dark-brown with a paler muzzle and belly and moult to a darker brown. In their first year as a juvenile they have a creamy mask around their eyes and a pale moustache. Juveniles of each species are similar in colour to adult females but smaller.

Biology of seals and sea lions

Like all mammals, pinnipeds breathe air, but - like whales and dolphins - they feed underwater. The mostly eat fish and squid.

Fur-seal and sea-lion facts and figures:

	Australian Sea-lion	New Zealand Fur-seal	Australian Fur-seal
Lifespan	Female ~ 26 years Males ~ 20 years	Female ~ 25 years Males ~ 19 years	Females ~ 21 years Males ~ 19 years
Delayed implantation	4 months	3 months	3 months
Gestation period	14 months	9 months	9 months
Total length of pregnancy	18 months	12 months	12 months
Number of pups per year	1 per 18 months	1	1
Pup survival rate (to weaning)	30 % to 18 months	50%	50%
Weight of pups at birth	7 kg	4 kg	5 kg
Weight of adult male	180-350 kg	85-160 kg	135-289 kg
Weight of adult female	60-110 kg	25-60 kg	40-120 kg
Breeding season	Variable - can be any month of the year	Summer (November-January)	Summer (October to December)
Deepest recorded dive	200 m	380 m	120 m
Breath-holding ability	12 min	15 min	9 min
Longest foraging trip by a female rearing a pup	120 km	1500 km	300 km

Normal Seal and Sea Lion Behaviour

Fur-seals and sea-lions haul up on the beaches and rocks to rest and can stay there for several days without eating anything. Mothers leave their pups on the shore when they go to hunt and return to feed them once or twice a week. Pups are able to survive for several weeks without feeding and are able to swim from an early age.  Well-intentioned people think because they look small and vulnerable, they need to be rescued. If the pup is moved, the mother will be unable to find it when she returns and it will be orphaned.

After pups become independent and are weaned they often appear on our metropolitan beaches looking small and skinny. Many of these juveniles are mistaken for abandoned pups, but should be left alone.

Intervention

The agencies responsible for marine animals generally have a non-intervention policy. They understand that the less humans interfere the better. However, there are circumstances where we do intervene, if it is practical and safe to do so:

• If the animal poses a human safety threat – eg when Henry is lying on an arterial road
• If the problem is caused by humans – eg if an animal is tangled in fishing line or rubbish.
• If the animal is clearly going to die and is suffering – if possible it will be humanely destroyed.
• If the animal is an orphaned juvenile, and if it is a species that will tame easily, and if there is a good captive home available for it consideration will be given to taking it into captivity
• If the individual is of particular significance – eg Henry is of particular importance to the people of Adelaide so efforts will be made to assist him.
• If the animal is of particular conservation significance - e.g. one of the few males left of a critically endangered species

Conservation status of seals and sea lions

All seals and sea lions are protected species. The Australian Sea-lion is listed as Threatened with many populations at a critically low level. A number of factors may be adding to vulnerability of sea-lion populations and hindering their recovery. Considerable research and monitoring efforts are now underway to identify and manage risk, and to ensure that populations can recover.

History of seals and sea lions in South Australia

The presence of large numbers of fur-seals and sea-lions was the reason for the European settlement of South Australia. The first white settlement on Kangaroo Island was by ‘sealers’ in the early 1800s. Fur-seals and sea-lions were hunted relentlessly for their skins and fat and at least 300 000 were killed. The seal trade stopped in about 1920 after numbers declined to such an extent that it was no longer commercially viable to hunt them. By this time, the settlers had expanded into agriculture and trade so they were not as dependent on sealing. Fur-seals and sea-lions became protected by law.

Since sealing was banned, South Australia’s fur-seal populations have grown steadily. However, the population growth of Australian Sea-lions slowed. While growth finally appears to be increasing, the Australian Sea-lion population does not appear to have recovered from the sealing era.