Take a stroll along almost any marina from Costa Rica to Alaska, and you"ll likely hear the playful barks of sea lions echo through the air. California sea lions, like the one pictured, are a common sight basking in the sun along the rocky shores of North America"s western coast. These marine mammals, belonging to the pinniped group, are often mistaken for seals. An easy way to distinguish between them is by looking at their ears—sea lions have visible flaps, seals don"t.