Elephant seals return to Año Nuevo State Park. Visitors watch battling bulls and 75-pound pups

Every winter about 10,000 elephant seals make their way to California's Año Nuevo State Park to fight, mate and give birth. During what park docent Laura Stern called “pupping season,” bull seals — some reaching up to 16 feet (4.9 meters) in length and weighing up to 2.5 tons — engage in bloody battles for breeding access to the females. “And we have about 10,000 elephant seals that come to Año Nuevo.”