Range

Australia is the native home of the Australian sea lion. Here they are found around the Southern and Western coastline in the states of South and Western Australia. Around ¾ live in South Australia with the rest in Western Australia.

Most populations live on around 50 islands off the coast though there a handful of mainland colonies.

A large population can be found at Seal Bay on Kangaroo Island off the coast of South Australia and this is a popular tourist attraction.

Habitat

Sea lions spend their time on land mostly on a sandy beach within an isolated bay area. Breeding populations are often found in areas with shallow pools in which pups can learn to swim.

They will make their way a decent distance up the shoreline in to dunes where they can hide under bushes or in rock holes. This is especially important for females who hide their pups in the bushes while they go off swimming.

Australian sea lions are non-migratory and spend most of their life near the breeding colony.

Reproduction

Breeding takes place anywhere from January to June and is variable depending on location.

Males will fight one another for breeding rights with a female. In crowded breeding sites they may form a harem and defend multiple females against other males.

Gestation lasts 14-15 months following which a single pup is born. Pups are a chocolate brown color at birth and will molt to their adult coloration at 3-4 months old.

Females leave the water one to two days prior to giving birth. They will spend 10 days on the beach with the pup before returning to the water to feed. When she does this the pup will be hidden in a bush or shrub.

Females continue this behavior of going feeding for a few days before returning to the feed the pup for a few days for the rest of the pups development. When she returns to the beach both the pup and the mother will call to one another to help them reunite.

The young are weaned at 1 ½ years old and females will breed once every 1 ½ years.

Infant mortality is as high as 50% by two years old in some populations. In some populations as much as 20% of the pups may fall victim to attacks by other Australian sea lions.

Sexual maturity is achieved between 4 and 5 years old. Males typically breed later than this as they need to achieve a large enough size to defend a territory against larger males.

Behavior

While diving under water the heart rate of an Australian sea lion will fall to 5 beats per minute.

When they are under the water their nostrils and ears close will close to prevent water entering. Throat muscles push against the wind pipe to ensure water is not able to enter the lungs if the mouth opens.

On land the Australian sea lion will stand up on their front flippers and use this to walk on their back flippers.

Predators and Threats

The main predator of the Australian sea lion is sharks.

One of the major threats to the Australian sea lion is fishing as it leads to them becoming entangled in marine debris such as nets.

Visitor disturbance is also threat as Australian sea lion populations often become a popular tourist attraction. In area where this occurs conservationists have started to build boardwalks where they can be viewed without people getting close to them.

Some sea lions may be shot by fishers who view them as a threat to the fish they are attempting to catch.

Estimates of the current populations vary depending on the study but are typically listed as being between 5000 and 13,000.

Australian sea lion populations were decimated in the early 1900s through hunting for their fur and oil. Populations are yet to recover.

Quick facts

They are the only seal found solely in Australia.

The Australian sea lion is the world’s rarest pinniped species.

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