Stellar Sea Lion Information and Status

In the span of less than 30 years between 1960 to 1989, the stellar sea lion’s world population dropped almost 64 percent. The reason for this rapid decrease is not entirely clear, but it is thought that heavy over-fishing has limited the species food supply and commercial fishing nets have killed thousands of the sea lions themselves. Indigenous people in the coastal regions in which the stellar sea lions live are permitted to hunt them for food, but only take around 300 hundred individuals each year. The IUCN lists the stellar sea lion as endangered and estimates a current wild population of around 105,800 to 117,800 with numbers still in the decline.

The biggest of all sea lions and the fourth largest of all pinnipeds after walruses and elephant seals, the stellar grows to over 9 feet in length and 1.2 tons in weight. It has a large, robust, torpedo-shaped body with large, flattened flippers and fused rear limbs that form a single flipper. The species has yellowish, buff, short coarse fur with no undercoat, so it relies on a thick layer of blubber to keep it warm in frigid waters. Male stellar sea lions are far larger than the females and have much thicker muscular necks that offer protection during fights with other males.

Stellar sea lions are Pacific Ocean semi-aquatic mammals, which are found along the coasts of Russia, Japan, Canada and the northern U.S. The species much prefers cold coastal waters over warmer southern waters, so they are not found too far south. They spend much of their time at sea, but they congregate in large numbers on beaches along the coast or on rocky oceanic outcrops. In the breeding season, thousands gather on the same beaches, while males battle for the right to mate with small harems of females.  

Entirely carnivorous, the stellar sea lion’s main prey includes a number of commercially fished species such as Pacific cod and walleye pollack. Squid and octopus are also common foods for the sea lion, as are smaller sea mammal species such as ringed seals and sea otters. Other than man, killer whales are the main known predator of the species, and great white sharks are known to take both adults and pups as well.

Each year in May, the stellar sea lions gather on the breeding beaches where males establish harems of 3-20 females in brutal battles with other males. Once the male and female have mated, fertilization is delayed for three months and the animals return to the sea. This extra three months, combined with the nine month gestation, mean that one year later the females return to the same beach to give birth to a single pup. The pups suckle from their mother for at least three months, but they may continue until the next breeding season. At one month old the pups can swim and at three months they can catch their own food. Females live longer than males, surviving up to 30 years in the wild, while the males violent lifestyle means they only live around 18 years.