California Sea Lion
Zalophus californianus
The loud, fast, extremely clever one that walks on its flippers.
If you've heard barking at a marina, that was a California sea lion. They're the athletes of the group — the fastest swimmers of any sea lion or seal, smart enough to be trained for serious work, and utterly unbothered about volume.
- Length
- Males up to 2.4 m (8 ft)
- Weight
- Males up to 390 kg
- Lifespan
- 20–30 years
- Diet
- Squid, anchovies, sardines, hake
- Dive depth
- Up to 275 m
- Breath hold
- Around 10 minutes
The good stuff.
Seal or sea lion? Check the ears
Sea lions have small external ear flaps. True seals just have a hole. Sea lions also rotate their back flippers forward and walk on all fours, while seals flop. And sea lions bark — seals really don't.
They swim with their arms
Sea lions row with their long front flippers like underwater wings. Seals do the opposite, sweeping their back flippers side to side. That's why sea lions are so much more agile.
The Pier 39 invasion
After the 1989 Loma Prieta earthquake, sea lions started hauling out on the docks at San Francisco's Pier 39. Hundreds still live there. The marina gave up and made them the main attraction.
The Navy works with them
The US Navy Marine Mammal Program trains California sea lions to find and mark lost equipment on the seafloor, because their low-light vision and hearing beat any machine.
Males grow a crest
Adult males develop a tall bony bump on the head called a sagittal crest, and the fur on it often turns lighter. It's how you tell a big male from a female at a glance.
Mums recognise a bark in a crowd
In a rookery of thousands of barking animals, a mother returning from days at sea finds her own pup by voice, then confirms by smell.
Wait, really?
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They can sleep floating at the surface with one flipper in the air — that flipper is a heat exchanger, warming or cooling the blood.
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Sea lions can be taught abstract logic tasks that most animals fail.
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Their whiskers, like a seal's, can track a fish through murky water.
What it sounds like
Nonstop honking barks — ork ork ork — plus growls and underwater clicks.
Where you might see one
The whole Pacific coast from Vancouver Island to Mexico. Pier 39 in San Francisco and La Jolla in San Diego are the easy ones.
The trouble
- Domoic acid poisoning from harmful algal blooms
- Entanglement in fishing gear and plastic packing bands
- El Niño years that starve pups
- Conflict with fisheries
One real thing
Cut plastic loops and bands before binning them. Sea lions grow into neck rings they can't get out of — rescue centres see it constantly.
More ways to help