They have large eyes that help compensate for low light levels in the underwater environment, while their whiskers increase their sense of touch.

As early as 1953, the zoologist Erling Sivertsen created a new indicative classification, after he investigated and catalogued again, in the Oslo Museum, skulls and archaeological remains, collected by the Norwegian expedition ship MK Norvegia between 1928 and 1929.

Furthermore, according to a molecular clock reconstruction, the Californian and Galápagos sea lions separated around 2.3 (± 0.5) million years ago.

During the breeding season, the males establish strictly guarded territories on the coasts and try to gain a harem from several females.

They are very sociable and are found in large groups, on cliffs, coasts, and even on human constructions, such as piers and navigation bowls.