Australia’s “Puppies of the Sea”

– Everything you need to know about the Australian Sea Lion.

By Rose and Bess

September is fast approaching and while for most people, that’s exciting because it means the end of Winter, Adventure Bay Charters are excited about something totally different; Sea Lion tours beginning again! With our first tour scheduled for the 2nd of September, we have never been more keen to get back in the water with our “sea puppies,” no matter how cold that water may be (we have very thick wetsuits for you)!

Every year, from the beginning of June to the end of August, we give the Sea Lions a little break from human interaction by stopping tours. While this is a necessary part of our business, it doesn’t stop our hearts aching at the thought of those little faces and what we are missing. We have spent more time than we’re willing to admit flicking through photos and videos from last seasons tours. We’re certain they have missed playing with us too, so now the countdown is on for our next play date. They are naturally curious creatures and love to show off. They love attention and that is how they affectionately became known as the “puppies of the sea.”

Sea Lion

Sea Lion



Scientific Name: Neophoca cinerea.


Life Expectancy: 12 to 16 years on average.

Diet: Fish, crustaceans, squid and octopus.

Structure: Their body is a streamlined, torpedo shape, allowing them to glide through the water.

Swimming: The sea lions front flippers propel them through the water, acting almost as wings, while their rear flippers act as a rudder to assist in steering.

Length: Pups are about 60 to 70 cm long at birth. Females average around 1.8m when fully grown, and males around 2.5m.

Weight: Females weigh up to 105 kilograms when fully grown and males up to 300 kilograms.


Male Australian Sea Lions are called “Bulls.” They are easily identifiable by their size and colour difference compared to females. Males grow much larger and darker in colour than females. Their neck and shoulders are more thickset and they are generally a dark brown colour with a golden “mane,” hence the name “Sea Lion.” Male sea lions reach sexual maturity at around six years of age and are incredibly territorial, particularly during breeding seasons. They will engage in fights to defend and to regain their territory.

Sea Lion               Sea Lion


Female Sea Lions are called “Cows.” They are much smaller and lighter in colour than the males. Females have no golden mane, a silver/grey colouring on their back and a lighter cream colour underneath. They reach sexual maturity at about four-and-a-half years of age and have one pup every eighteen months to two years. Mother’s will move their pups away from their birthplace to a “haul-out zone” when they are about two months old. Here, they continue nursing and shelter them from bullying and possible death by territorial males. These super mums are responsible for every aspect of the pups life. The female will spend months teaching her baby how to hunt, gather, feed, swim and every life skill in between.


Baby Sea Lion, or “Pups” are about sixty to seventy centimetres long and a dark chocolate brown colour at birth. As they get older, they become a silvery/fawn colour similar to that of the females. There is a strong bond between mum and pup as the babies stay with their mums from eighteen months to three years. Nursing lasts fifteen to eighteen months or until the next pup is born. We notice the pups we swim with are super playful and energetic, jumping in and out of the water and zooming around like little underwater rockets!

Sea Lion


Australian Sea Lions are found along the West Australian coastline and islands of South Australia. The largest populations are found on Kangaroo Island and on Dangerous Reef near Port Lincoln. Small numbers are found along the west coast of South Australia and along the coast of Western Australia. Few still live in Tasmania. There once was a large breeding colony in the Bass Strait, which was entirely wiped out by the sealing industry.

On our tours, we have the opportunity to dive at four different haul-out zones on islands just off Port Lincoln in the Memory Cove Wilderness Protection Area and the Sir Joseph Banks Group Conservation Park. These are small beaches on Hopkins Island, Grindal Island, Langton Island and Blyth Island.

Sea LionSea Lion

Photo credit: Jem Cresswell. Location: Memory Cove.


The Australian Sea Lions have an eighteen month breeding cycle; different to other Sea Lions where cycles typically last about twelve months. The time of the breeding season is different for each colony. Here in Port Lincoln, pups are generally born any time between January and June.

The breeding cycle begins when the females enter estrus (a stage of sexual receptivity), starting six days after giving birth. Males will herd the female Sea Lions into groups of four or five and mate with all at one time. They often fight other males over a female, as there is only a twenty-four hour window in which estrus lasts.

Occasionally, males kill the pup she has just given birth to in order to get her to mate again. Aggressive behaviour displayed by the colony males, means a high mortality rate in pups, contributing to their declining population. The population is also diminishing due to such a slow reproduction rate (one pup every eighteen months). Female Sea Lions demonstrate “fostering” behaviours toward pups not their own. They will adopt and nurse them if they have been abandoned or their mother has been killed. A behaviour likened to babysitting has also been observed. Females will take turns to watch over and protect a whole group of pups when other females leave to hunt. Interestingly, males are not at all protective of the pups and are sometimes seen biting or shaking them to death.


Unfortunately, for these beautiful animals, one of their biggest threats is themselves. A slow reproduction cycle, a high mortality rate in pups and past hunting activities are the biggest issues. While the practice of clubbing was stopped in the 1920’s, their population has not recovered. In conjunction, fisheries play a major threatening role. Sea Lions often become fisheries by-catch when tangled in fishing nets while hunting. This entanglement leads to injury and drowning. Their natural predators are sharks, who have modified and exceeded their hunting skills over the years.


It is so important to teach and educate about these precious little creatures and see them in their natural habitat. They are such sweet animals that need protection and appreciation, hence the endangered status. Them being a threat to their own population is something we only wish we could communicate to them to stop.

If you’re not inspired by now to join our Sea Lion swim, scroll our Instagram to be inspired @adventurebaycharters. We cater for everyone and so do our Sea lion loves. With family packages, disability support and floatation devices, there is a way for every person to enjoy this. All ages and abilities welcome. Remember, this species is listed as endangered and this is your chance to naturally get close to them.


  • sealions are one beautifull oncen animal a like to help to save them for as a volunteer a worked with IFAW and any animal organizions a can be conated

    • Thanks for the comment Harry and it sounds like you’ve done some great work in the past. Keep it going! It’s people like you who will help protect them for future generations.

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