How to Identify Sea Lion in California

California sea lions have large, pointed external ear flaps that stick out from their head, unlike seals which have ear holes with no flap. Their face is dog-like and elongated, with a pointed snout and large dark eyes. The profile is sleek and streamlined when they are in water, but on land their front of their body sits higher as they prop themselves up with their flippers. The ear flap is the single fastest way to distinguish sea lions from harbor seals at Monterey Bay, Point Reyes, or San Diego coast locations where both species haul out.

Adult males weigh 200 to 380 pounds and are noticeably larger and darker than females, which typically weigh 110 to 180 pounds. Males develop a pronounced sagittal crest (a bony ridge on top of the skull) that creates a visible bump or dome on their forehead as they age. Younger males and females are smaller and more uniformly colored. Pups are dark brown and weigh less than 50 pounds for the first year.

Sea lions have visible ear flaps, dog-like faces, and can rotate their hind flippers forward so they gallop on land like a four-legged animal. Harbor seals have ear holes without flaps, rounder heads, and cannot rotate their hind flippers forward so they hump along like a caterpillar. Sea lions are much more vocal and often bark loudly. If you see a pinniped on land making loud calls and using its rear flippers like legs, it is almost certainly a sea lion.

California sea lions have dark brown or tan coats that darken with age. Pups are born dark brown or black. Wet fur looks much darker than dry fur. Some individuals show lighter patches on their chest or belly. There are no distinct stripes or spots like some other marine mammals have. The coat is short and sleek, without visible guard hairs or patterns that would help with camouflage.

Sea lions are extremely vocal animals, barking and bellowing constantly, especially when hauled out. Adult males often bark in territorial defense or during breeding season. This loud behavior is one of the easiest ways to identify them from a distance. They are also highly social and often rest in large groups on rocks and beaches. At Channel Islands and Monterey Bay haul-out sites, the chorus of barking can be heard hundreds of yards away.

Steller sea lions are much larger (males up to 1,200 pounds), lighter in color, and have blockier, wider heads. California sea lions are smaller and sleeker with narrower, more dog-like faces. Steller sea lions are less common in most of California (more northern range) but do occur on the far north coast. If you see a very large, pale-colored sea lion in northern California near Humboldt County, it might be a Steller, but most sea lions from Monterey Bay south are California sea lions.

California sea lions have long, powerful front flippers that they use to prop up their body and rotate under their torso to gallop forward. Their hind flippers can rotate forward, allowing them to walk and run on land. This gives them a four-legged galloping gait that is completely unlike the humping motion of seals. In water, they are incredibly agile swimmers, using their front flippers for steering and their rear flippers for propulsion.

Sea lions have long, sensitive whiskers (vibrissae) that extend from their muzzle and face. These help them sense movement and locate prey underwater. Their eyes are large and dark, positioned on the sides of their head for good peripheral vision both in water and on land. They have functional tear ducts and can shed tears. These sensory adaptations help California sea lions hunt effectively in the kelp forests and open water off Monterey Bay, the Redwood Coast, and Channel Islands.

The California sea lion (Zalophus californianus) is the primary species throughout most of the state. It is the species you are most likely to see from Monterey Bay, Point Reyes, Channel Islands, and San Diego coast. Steller sea lions (Eumetopias jubatus) occur in small numbers along the far north coast near the Oregon border but are rare south of Humboldt County. All the major sea lion haul-out sites in central and southern California are California sea lions.

Pups are dark brown or black at birth and much smaller. As they grow, they gradually lighten to tan or light brown by early adulthood. Adult males continue to darken with age and develop the characteristic forehead crest or bump. Very old males can become almost black. Female color does not change as dramatically with age, but older females may be slightly darker than younger animals.