African fur seal

Species

There are 8 species of fur seal in the Arctocephalus genus. The South African fur seal is a subspecies of the brown fur seal. The other subspecies is the Australian fur seal. These subspecies separated from each other fairly recently (about 12,000 years ago). NZ has its own species of fur seal too.

Arctocephalus pusillus
: Arctocephalus pusillus pusillus
: Arctocephalus pusillus doriferus
(Arctocephalus fosteri)

Brown fur seal
: South African/Cape fur seal
: Australian fur seal
(NZ fur seal; kekeno)

Population

The South African, Australian and NZ fur seals are all classified as of least concern. There is though to be

Size

Males measure 1.8 - 2.3 metres in length and weigh between 200 and 360 kg. Females measure 1.2 - 1.7 metres and weigh 35 - 110 kg. The brown fur seal is the largest fur seal species.
(The NZ fur seal is smaller with males 1.45 - 2.5 m long and weighing 12 -150 kg. Females are 1.25 - 1.5 m in length and weigh 40 - 70 kg.)

Habitat & distribution

The coast of Namibia and South Africa is home to one of the largest fur seal colonies in the world. At Cape Cross (where I saw the South African fur seal) there is an estimated 200,000 seals. When it's not breeding season, the distribution of the fur seals is larger. This area is nutrient rich due to the Benguela current and is great for fish. Fur seals prefer the ocean and come to shore to rest and breed.

What is a pinniped?

The word pinniped is derived from the Latin words "pinna" meaning "fin" and "ped" meaning "foot".
There are 33 species of pinnipeds in 3 families :
- walruses (Odobenidae) found in arctic areas
- sea lions and fur seals, or true seals (Phocidae) and
- eared seals (Otariidae).
True seals do not have external ears, cannot turn their hind flippers forward (therefore can not walk on them), and have fur on both surfaces of their flippers. Examples in New Zealand include the leopard seal and the southern elephant seal.
Eared seals have external ears, hind flippers they can turn forward under the body and walk on and no fur on the under side of their flippers. Examples are the NZ fur seal (kekeno) and the NZ sea lion (rāpoka / whakahao). While the fur seal does have external ears, they are genetically more closely related to sea lions.

Diet

South African fur seals can feed up to 180km offshore on schooling fish (such as sardines, anchovies, bearded gobies, mackerel and demersal hake), cephalopods and crustaceans. They may also eat Cape gannet, cormorant or African penguin.

Interesting facts

~ The South African fur seal can dive to depths of 400m. Australian fur seals dive to 200m.
~ Fur seals can sleep in the water. They either sleep in a standing position or horizontally on their backs.

Group

A group of seals is called a colony. Non-breeding juveniles are often found in a colony at a non-breeding site. A group of pups is called a pod. Pups will often group together while their mothers are off at sea feeding.

Breeding & lifespan

Males (bulls) arrive at breeding sites first and fight for territory. Females arrive and each male will have a harem of 7-30 females. When the females arrive, she will give birth to one pup after a gestation period of 8 months. A week later, she will mate. However, the fertilized egg will not develop for another 4 months. This is known as delayed implantation. (More than 130 species of mammals and some marsupials use delayed implantation).
South African fur seal pups are 60-80 cm long when they are born and weigh 5-6 kg, with males slightly bigger. The area where the pups are born is called a rookery. The female (cow) suckles the pup for 8-10 months. Pups stay on land for several months before they are ready to venture into the ocean.
In the wild, South African fur seals can live up to 25 years.

Predators & threats

Sharks and killer whales prey on South African fur seals. Pups on land are also prey for black backed jackals and brown hyena.
While most countries have made hunting seals illegal, commercial seal hunting is still permitted in Namibia (but not South Africa, which banned hunting in 1990). Fishermen and the government believe that culling seals will help restore fish stocks despite evidence not supporting this claim. The quota is 80,000 - 85,000 pups and 6,000 males. The hunting season is from Aug-Sep to November.
Seals are also threatened by the fisheries industry. South African fur seals get caught in fishing lines (line, trawl & purse-seine) and in nets.