• otarie_steller
  • otarie_steller

Steller Sea Lions

Eumetopias jubatus




Oceans and seas

Interesting facts

Right before mating season, the males eat a lot, building their mass to a weight of nearly 1,000 kg.  That extra weight then allows them to fast throughout the entire mating season.  


Near threatened

The Steller sea lion is the largest of the 16 species of sea lions.  It has a very large body, a broad chest and a mane of fur. The colour of its fur is reddish brown.  Their heads are very large, with a flat nose.

Environment and behavior

Sexual dimorphism is very pronounced. The species is polygamous and, once adult, the males can weigh up to three times as much as the females. The male arrives on the beach before the female. It is only after age 9 that males are able to defend their territories and mate.  Mating season is between the end of spring and the beginning of summer.  Gestation lasts one year, taking into account a delayed implantation period of approximately 3 months.  That is a period during which the female is fertilized, but the embryo does not develop.  If the mother encounters favorable conditions (good diet and no disease), the fetus will develop. The baby is born between May and July. The mother stays on land for 7 to 10 weeks, without leaving her child, in order to nurse.  She then slowly starts to move away, for periods of 18 to 25 hours.  She is fertile again 2 weeks after giving birth. Although they can travel long distances, Steller sea lions are not considered migratory. Only the young travel long distances and move away from the rookery.  Adults, on the other hand, show rather sedentary behavior.


Killer whales, certain sharks and man.


Population of the East Pacific Ocean: Many sea lions were slaughtered between the 1950s and 1960s and, to a lesser extent, in the 1970s. The population has been gradually increasing since the 1970s. Population of the West Pacific Ocean: This population has declined by 70% to 80% since the 1970s. Several possibilities have been considered: slaughtering by fishermen, by-catching in fishing nets, disease, pollution, loss of food resources, etc. According to recent studies, different environmental factors, in addition to predation by killer whales, could have a strong impact on the population. The population has turned around a little since the 2000s.