It has small external ears and broad front flippers and lives along the Pacific coast of North America.
Small ear flaps protrude behind the eyes. Harbor seals have no external ear flaps.
Ronan, a female California sea lion living at a Santa Cruz research facility, can move her head up and down to regularly spaced sounds and adjust her movements when the tempo changes. She began practising at age three and continued to demonstrate beat matching at fifteen.
In a 2025 study, Ronan and ten undergraduates responded to identical snare-drum tracks. She marked beats with downward head movements; humans used downward arm movements. Each completed four trials at 112, 120 and 128 beats per minute; 112 and 128 were novel tempos for Ronan. She made one bob per beat. Her movement-interval variability was lower than that of every human participant at all three tempos, demonstrating flexible timing beyond the familiar 120-beat rate.
An extinction-risk assessment has not been added yet.
Entanglement in fishing gear can cause injuries and interfere with swimming and feeding.
NOAA identifies toxins from harmful algal blooms as a threat to California sea lions. Domoic acid can cause seizures or death. Its conservation work includes responding to stranded and injured animals in cooperation with trained response organisations.