The Australian sea lion is a species of sea mammals. Males are enormously large, reaching a huge size: sometimes they can be 3 times bigger than females. Other distinctive features of these sea lions are: muzzles - tapered, long and narrow; sagittal crests on their skulls; extremely small ears, lying close to their heads. Males of the Australian sea lion are dark brown in color whereas females are silver. Young are also dark brown, having dark mask on their face and a pale crown.
Australian sea lions live mainly in isolated bays as well as on ocean and sandy beaches. The area of their distribution includes islands, offshore of Australia; these sea lions are found from Western Australia to islands in southern Australia. Due to being excellent climbers, the Australian sea lions can be seen on cliffs, sometimes climbing as high as 30 meters.
The sea lions are mainly diurnal. They are highly sociable and communicative animals, gathering in large colonies on the land. They also congregate into more intimate social units – subgroups - that contain 10-15 individuals on average. They can move from one subgroup to another, depending on their needs. Since the sea lions are non-migratory animals, they usually remain near to their birthplace throughout the life, living and breeding on sandy beaches. Looking for food, they can dive up to 600 feet, staying up to 40 minutes under the water. Some sea lions have been known to swallow small stones: perhaps, it’s done to balance the weight when diving under the water.
Australian sea lions are carnivores (piscivores, molluscivores). Their regular diet includes octopus, blue-throated wrasses, squids, fairy penguins and cuttlefish. They also eat certain species of fish such as small sharks, rays and whiting.
The Australian sea lions are polygynous, meaning that one male can mate with multiple females. Males engage in fights, in order to be allowed to mate with females. Breeding cycle of these sea lions is about 1.5 year while gestation period lasts 11 months, after which a single baby is born. The pups usually live with their mother during the first year after birth. They often join groups of other pups, where they play together and participate in mock battles. Weaning takes place at the age of 15-18 months while sexual maturity is reached as the age of 3-6 years.
One of the major threats to this species is fishermen. The sea lions frequently become entangled in fishing nets and die there. Chemical pollution, noise pollution, oil spills as well as diseases are among factors, threatening the sea lions’ population. On the other hand, sealing has caused large reduction of the overall population. Other important threats are human disturbance, intentional killings, climate changes, depletion of suitable prey, loss of habitat and aquaculture operations.
The overall population of the Australian sea lions is currently decreasing, and in the UICN Red List the species is classified as Endangered (EN). The total number of population varies from 12.290 to 13.090, including 6.500 mature individuals.
Sea lions control prey species population in the area by eating penguins, fish and other marine aquatic.