Steller Sea Lion

Steller Sea Lion (Canadian Wildlife Federation)

Species: Steller Sea Lion – Eumetopias jubatus
B.C. Status: Special Concern

Key Information: 

Steller sea lions, also known as northern sea lions and seawolves, are the largest member of the marine mammal family called Otariidae (which means “eared seals”). Their habitat ranges from the cooler temperate to the subarctic regions of the North Pacific Ocean — from California to Japan. Although they are considered non-migratory, individuals may roam large distances from the breeding sites.

Steller sea lions are foragers and predators, excelling at hunting a wide variety of other animals. These include more than one hundred species of fish (such as herring, mackerel and salmon), squid and octopus, and occasionally seal pups. Stellers are opportunistic hunters and tend to concentrate on the most abundant prey in their locale. They are sometimes hunted by larger predators such as killer whales and sharks, and may also be killed by humans, for example as part of predator control at fishery perimeters.

Like other sea lions, Stellers are highly social animals. They regularly rest and interact on land, returning to established year-round haul-out sites that tend to be isolated, barren islands or beaches. Individuals will pile up next to or even on top of each other until the rocky shore seems to be alive and heaving with movement. In British Columbia, Steller sea lions have rookeries in three locations: off the northeastern tip of Vancouver Island, off the southern tip of Haida Gwaii, and off the northern mainland coast. These are some of the largest congregations of Stellers worldwide.

The main gatherings occur during the annual breeding season, from May to late summer. Mating and birthing both take place on dry land, and mature males (around 9 or 10 years old) must secure a large area of the beach to attract females. The bulls stay on land protecting their territory, fasting for 40 days or longer. Females become fertile starting around 5 years of age, and commonly give birth to one pup per year. The mothers must leave and hunt underwater daily to feed their young. Upon return, they recognize their own pup in the throng through scent, touch, and vocalizing, which is akin to humans calling out each other’s names.

British Columbia is the only place in Canada where the Steller sea lions live. This group falls under the species’ Eastern population segment, which has shown some stable recovery in recent decades. The Western population segment (west of the 144° west longitude) unfortunately continues to decrease in numbers. Some suspected causes are illegal hunting, off-shore oil and gas exploration, both direct and indirect impacts from the fishing industry (boat strikes, competition for food, netting accidents, etc.) and habitat degradation.

Stellers are a good example of an indicator species that can give scientists clues to the pressures on an ecosystem. Since these mammals have a relatively long lifespan, a wide-ranging habitat, and are high up on the marine food chain, their population numbers can be indicative of changes in their environment.

Identification – what to look for:

• Tan to golden-brown coat of hair, with darker flippers and underside; the colour appears dark gray when wet
• A squarish head similar to a bear’s, with whiskers to help sense prey underwater
• Male Stellers have longer fur on their thick necks, which resemble a lion’s mane
• Stellers are much bigger and lighter in colour than the California sea lions

Where are they found?

• Mainly in the coastal regions of the North Pacific Ocean Rim
• From California to Alaska, further north to the Bering Strait and eastward to Northern Japan
• British Columbia is the only place in Canada where Stellers reside

Cool facts!

• Steller bulls (males) weigh about 2,500 pounds and are around 11feet long! Males are at least twice as heavy as the females weighing in at 1,000 pounds and 9 feet long.
• Females live 6–10 years longer than males on average.
• Sea lions can turn their back flippers forward on land, which lets them walk and even climb onto rocks and cliffs.
• A group of Steller sea lions has different names depending on the context: a colony when they are on dry land, a raft when in the water, and a rookery during breeding season, when the females fought for and guarded by each dominant male are called a harem.
• Sea lions can hold their breath for as long as 40 minutes and can swim as fast as 40 km/h to outswim predators.
• Stellers have been found up to 200 km off-shore hunting for food!

Useful links:

UBC–Marine Mammal Research Unit
Canadian Geographic–Steller Sea Lions
Animalia–Steller Sea Lions
The Marine Mammal Center–Steller Sea Lions