Every winter, dozens of elephant seals make their way to the beaches at Greater Farallones National Marine Sanctuary and other West Coast sanctuaries to mate. Each year between December and February, elephant seals come to shore to breed. Males -- like the two seen here -- arrive first and fight for territory on the beach in quick, aggressive battles. Though males may experience minor injury as a result of these battles, severe harm or lasting damage rarely occur. Following establishment of territories, females arrive and the mating season ensues. Each pregnant female then gives birth to a single pup, who she'll nurse for about a month before returning to sea.