Australian Sea Lions (Neophoca Cinerea) are listed as “Endangered” by the International Union for the Conservation of Nature (IUCN) They have been afforded legal protection in Western Australia as a “Special Protected Species” from as early as 1892 and have received full protection from the Australian Government since 1964. They suffer from entanglement in shark nets as well as general marine debris and commercial fisheries nets. Loss of habitat, human interference and high pup mortality rates all work towards their continued demise. Although illegal shootings do occur, they are less frequent than most other species.
Australian Sea Lions prefer to haul out on small off-shore islands to breed. The breeding season is usually quite long, around 5 months. Males are unable to protect their territories for the entire period and so will spend up to four weeks at a time maintaining a small harem. They become very aggressive towards other males during this time.
Australian Sea Lions are unique in that they have a 17 month breeding cycle. Pupping alternates according to summer or winter and different breeding colonies will have different pupping seasons.
Females usually give birth 1-2 days after coming on shore and will mate roughly one week after. Pups weigh in at approximately 7kg and measure around 65cm in length. Male pups tend to be slightly larger.
The female will remain with her newborn for the initial 10 days before hunger forces her to go off foraging. She will abandon the pup for a period of two days while she feeds before returning to nurse and suckle for a day or two. This cycle continues until the pup is fully weaned, at around 18months, though extended weaning has been known to occur. (as long as 23 months)
Pup mortality in this species tends to be relatively high. (40-50%) This is mostly due to the extreme aggression displayed by both males and females.
Females reach sexual maturity when they are between 4-6 years of age. Adult females weigh in at between 65kg and 110kg measuring on average 1.5m in length. Males take longer to reach sexual maturity, usually between the ages of 8-9 years. The males tend to be much heavier and longer, weighing up to 300kg and measuring just over 2m in length. Australian Sea Lions live for around 25 years.
Australian Sea Lions are one of the most endangered of the pinniped species. Population estimates put them at between 3-5 thousand animals.
Their biggest natural predators are sharks, particularly White Pointer Sharks.
They have no sub-species and are also known as White-Capped Sea Lions.
Males and females tend to vary in colour. Males are almost always a dark brown, while females tend to be more fawn or silvery grey in colour with a lighter underbelly.
Although this species may travel great distances to find food, (a diet of lobster, crustaceans, octopus and sea birds) they are non-migratory and will always return to their home turf.
80% of the population lives in South Australia with the remaining 20% living in Western Australia .
Of the 73 known breeding sites, only 5 produce in excess of 100 pups each year. This represents 57% of all pups born.
Unlike many pinniped species that have recovered from commercial exploitation during the 18th, 19th and 20th centuries, the Australian Sea Lions numbers have not stabilised. Populations are currently at an all time low and numbers continue to dwindle.
Pups will often congregate in shallow rock pools. These areas serve as nurseries and are important places for the animals to learn and develop their hunting skills while still remaining in relative safety.
While seal tourism is considered an excellent alternative to culling seals for commercial purposes, one needs to take into account what this new form of human interference will have on the animals. Recent studies suggest Australian Sea Lions are exceptionally susceptible to interference and tourism aspects need to be conducted responsibly.