Pinni = winged Ped = foot
The order Pinnipedia can be divided into three families.
- Odobenidae (O-do-ben-i-day) - walrus
- Otariidae (O-tar-i-day) - eared seals, sea lions and fur seals
- Phocidae (Foe-sid-ay) - true seals
Adult males are called bulls and the females are cows. The young seals are known as pups while a baby walrus is called a calf.
We spent the week looking at seals that you may find in Australian waters.
The Southern Elephant Seal (Mirounga leonina) is the largest of all pinnipeds and belongs to the true seal family (Phocidae). It breeds on the subantarctic islands and is an occasional visitor to Australian shores. There was once a population of elephant seals found on King Island until the 19th century, when the population was hunted until it no longer existed. The blubber of an adult male can be 10cm thick and in the sealing days one seal could yield up to 400L of oil.
Australian seals were hunted commercially from the late 1790s for their pelts, meat and oil. All three species that breed in Australia were almost hunted to extinction by 1830. Bans on sealing followed and all seals have been fully protected in Australian waters since the 1980s.
The Subantarctic Fur Seal (Arctocephalus tropicalis) is another occasional visitor to Australian shores. It is the first of our eared seals. Notice the small ears and how the elephant and leopard seal had none. Can you see any other differences?
The male subantarctic fur seal arrives at breeding sites, on the subantarctic islands, before the females to map out their territory. They defend their territory with a lot of noise, bluff, and, if needed, fighting. The females start arriving around November and give birth to a single black pup within a few days of arrival at the colony. They then mate about a week later.
Male New Zealand fur seals arrive at colonies in late October to find and defend their piece of land before the females arrive. Each male has 5-8 females within his territory. The pups are born from mid November to January. The female stays with the pup for 1-2 weeks before she starts to go on small food foraging trips.
The Australian Fur Seal (Arctocephalus pusillus) is the largest of the fur seals with males often weighing more than 300kg. Females are smaller reaching up to 110kg. The Australian fur seal is an excellent swimmer and can dive to depths over 130m while searching for food. Australian and New Zealand fur seals are very similar in appearance, you can use their teeth structure to tell them apart. The Australian seals have large teeth with three cusps and the New Zealand seal have smaller teeth with one cusp. So if you don’t mind fish breath identifying them will be a breeze. The Australian and New Zealand fur seals also like different colony sites. The Australian fur seal prefers a exposed rocky site while the New Zealand fur seal likes a site that is more sheltered by boulders.
Our last seal was our first seal pic, the Australian Sea Lion (Neophoca cinerea). Female Sea Lions are a silver ash colour and reach about 80kg in weight. Males are chocolate-brown and can weigh up to 300kg. Australian sea lions have the longest weaning period of any seal species, with pups staying with their mum for 18 months. Researchers usually look at seal faeces (poo) to identify what they eat. This doesn't work for the Australian sea lion, as its prey is so ground up there are very few identifiable parts. Some researchers have been using Crittercams to answer the question of the sea lion diet. Unlike fur seals, the Australian seal lion is unable to rest in the water and has to come ashore for a sleep.
Australian Geographic (2011) January – March, Issue 101.
Edgar, G.J. (2000) Australian marine life: the plants and animals of temperate waters.
Some web sites
Australian Antarctica Division
There are also some great (cute) pics here.
Australian Government - Department of the Environment and Energy
ICUN Red List
Hope you are as excited about seals as these two are.