Green turtles have a reproductive strategy known as “scramble polygamy.” Rather than expend energy defending a territory or engaging in combat, males focus their elephantine effort on finding an unattached female—or attempting to cut in on a mating in progress. Males have large claws on their flippers and tail, and use these to attach themselves to the shell of the female. Other males attempt to knock a successful paramour off his perch, jousting and biting and often wounding both members of the pair.
Occasionally a hormone-addled rival will clip on to the shell of the mounted male. “This is going absolutely nowhere for male number two,” notes marine biologist Wallace J. Nichols. Nichols has seen stacks of up to four males, each clinging to the turtle in front. “When this sort of thing happens with earthworms in the garden, it’s merely curious,” he observes. “With 400-pound sea turtles, it’s a circus.”