The largest males win territorial competitions and are able to defend large areas of beaches. This gives them access to more females and increases their reproductive success.
Males wait for females to arrive at the beach, and then choose the area with the largest number of females to gain access to mates.
Males defend an area of beach that is relative to their age-the oldest males have the smallest territories.
Males only come up on the beach to mate. Once they have mated with a few females they return to the ocean to feed until the following year.