Australian Sea Lion Fact File
The Australia sea lion has a stocky body with short flippers. Males and females are able to be distinguished as the males have a darker coat color.
On their back males are dark brown or grey and this can appear black if they are wet. Females are silvery grey or fawn. On the underside they are a pale color often tan. A male will have a large neck with a mane of fur. This mane is often yellow.
They have a pointed snout which is tipped with black and has long whiskers on either side.
Australian sea lions are members of the ‘eared seal’ group and have a small external ear.
Their eye has a third eyelid which can covers the eye to protect it but is clear so they can still see. Their eye also has a reflective membrane at the back of the eye which bounces light through the eye twice to help with vision in low light areas.
The larger male measures 1.6-1.9m (5.3-6.2ft) long and females measure 1.3-1.5m (4.3-4.9ft). They weigh 90-160kg (198-353lbs) for males with the much lighter females weighing just 35-50kg (66-110lbs). Some large females have been recorded at as much as 100kg (220.4lbs) and males have been recorded reaching as much as 400kg(881.8lbs).
The Australian sea lion is a carnivore. They primarily feed on fish, birds, octopus and squid. Most of their prey is hunted on the sea floor. Most food will be swallowed whole though some is brought the surface to break apart.
An adult female sea lion will require 8-10kg (17.6-22lbs) of food per day. They may consume 1/3 of their body weight in a feeding trip.
Wild 8-9 years
— AD —
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.
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.
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.
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.
They are the only seal found solely in Australia.
The Australian sea lion is the world’s rarest pinniped species.
Copyright. The Animal Facts.
Slater, P. and Parish, S., 2016. First Field Guide To Australian Mammals. 1st ed. New South Wales: Pascal Press.
Interpretative displays at Seal Bay Visitor Centre
Australian Marine Conservation Society. 2020. Australian Sea Lions – Australian Marine Conservation Society. [online] Available at: <https://www.marineconservation.org.au/australian-sea-lions/> [Accessed 11 August 2020].
Sealbay.sa.gov.au. 2020. About Australian Sea Lions – Seal Bay – Department For Environment And Water. [online] Available at: <https://www.sealbay.sa.gov.au/australian-sea-lion/about-australian-sea-lions> [Accessed 11 August 2020].
The Australian Museum. 2020. Australian Sea Lion. [online] Available at: <https://australian.museum/learn/animals/mammals/australian-sea-lion/> [Accessed 11 August 2020].
Australian Government Department of Agriculture, Water and the Environment. 2020. Neophoca Cinerea — Australian Sea-Lion, Australian Sea Lion SPRAT Profile. [online] Available at: <http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=22> [Accessed 11 August 2020].
2020. Australian Sea-Lion Neophoca Cinerea. [ebook] Adelaide: Natural Resources Adelaide and Mount Lofty Ranges, pp.1-2. Available at: <http://file:///C:/Users/User/Documents/The%20Animal%20Facts/news/August%202020/10%20August%20-%20Beluga%20SEA%20LIFE/australian-sealion-bio-region-fact.pdf> [Accessed 11 August 2020].
Pinnipeds.org. 2020. Australian Sea Lion. [online] Available at: <https://www.pinnipeds.org/seal-information/species-information-pages/sea-lions-and-fur-seals/australian-sea-lion> [Accessed 11 August 2020].