Sea lions sleep on a pontoon dock at Pier 39 in the harbor of San Francisco, California November 8, 2005. The sea lions began appearing at the pier [shortly after the 1989 earthquake. Soon the sea mammals began arriving in droves and taking over the docks. Due to plentiful herring supply and available dock space in a protective environment, the population quickly grew to more than 300. Today the population grows to as high as 900 in winter months.]