Australian Sea Lion

Australian Sea Lion
Vocalizing on Beach
Conservation status
Endangered (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Suborder:	Pinnipedia
Family:	Otariidae
Subfamily:	Otariinae
Genus:	Neophoca Gray, 1866
Species:	N. cinerea
Binomial name
Neophoca cinerea (Péron, 1816)
Australian Sea Lion range

The Australian Sea Lion (Neophoca cinerea), also known as the Australian Sea-lion or Australian Sealion, is a species of sea lion that breeds only on the south and west coasts of Australia. It is monotypic in the genus Neophoca.

Phylogeny

The Australian Sea Lion is a pinniped most closely related to other species of sea lion and fur seal in the family Otariidae.

Breeding behaviour

The breeding cycle of the Australian sea lion is unusual within the pinniped family. It is an 18 month cycle and is not synchronised between colonies. The duration of the breeding season can range from 5 to 7 months and has been recorded for up to 9 months at Seal Bay on Kangaroo Island.

Bulls do not have fixed territories during the breeding season. The males fight other males from a very young age to establish their individual positions in the male hierarchy and during the breeding season, dominant males will guard females for the right to breed with her when she comes into oestrus. A female comes into season for about 24 hours within 7 to 10 days after she has given birth to her new pup. She will only look after the new pup and generally fights off the previous season's pup if it attempts to continue to suckle from her.

Male Australian Sea Lions are also known to kill young as an act of defence of territory.

Sea lions on Kangaroo Island beach

Population status and protection measures

There are approximately 14,730 Australian Sea Lions^[2] following the introduction of the Australian National Parks and Wildlife Act of 1972 which prohibited a harvest that began in earnest as soon as Europeans colonised the continent.

Analogous and homologous structures

The Australian Sea Lion has many analogies with other species. For instance, sea lions use their flippers in a wing-like motion to propel themselves through the water. This is an analogous feature shared among many animals. Penguins, for example, are from a completely different class (birds) but also use a similar method of swimming underwater; their wings serve little point on land whereas in the water their wing structure acts similarly to flippers and allows them to dart around quickly underwater. Sea lions are similarly fast underwater and this helps them to catch their prey.

Australian sea lions have very well-developed facial whiskers. Like all pinnipeds, such as seals and walruses, this useful homologous structure helps the sea lion to feel their way under the water and sense their prey. This is an inherited feature shared amongst all of the sea lion's close relatives.

References

1. ^ Goldsworthy, S. & Gales, N. (2008). Neophoca cinerea. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 30 January 2009. Listed as Endangered (EN A2bd+3d)
2. ^ "Wildlife as Canon Sees It". National Geographic Magazine (National Geographic Society) 218 (6). December 2010. "Surviving number: Estimated at 14,730" 

• Shannon Leone Fowler (2005). Ontogeny of diving in the Australian sea lion. Ph.D. thesis. University of California, Santa Cruz.

• Randall R. Reeves, Brent S. Stewart, Phillip J. Clapham and James A. Powell (2002). National Audubon Society Guide to Marine Mammals of the World. Alfred A. Knopf, Inc. ISBN 0375411410.