Orientation and behaviour of hatchling green turtles (Chelonia mydas) in the sea

To investigate the initial stage of the ‘lost-year puzzle’ of sea turtle ecology, both hatchlings from the natural nesting groung at Tortuguero, Costa Rica and hatchlings from Tortuguero eggs that had hatched in a beach on Bermuda were tracked individually after their departure from these beaches. Of the Bermuda beach most were tracked by swimmers equipped with face mask and flippers and followed by a boat. Tracking off Tortuguero was done by an observer in a following boat. The data showed that non-random departure courses were maintained even when swimming hatchlings and moved over the horizon from all fixed objects on the shore. Observations were made on swimming and diving behaviour and on predator relationships of travelling turtles. The procedures described are useful research techniques and will be used for more extensive tracking in future seasons.