African baby turtles start life with a 24-hour swimathon


(Image: Rebecca Scott, GEOMAR)


Baby loggerhead turtles from Cape Verde off the coast of West Africa start life with a 24-hour marathon swim.


But then like the green turtles in Finding Nemo , these diminutive loggerheads become chilled-out surfers.


The period between the babies' breakaway from the beach and their eventual return as adults has been called the "lost years", because the tiny creatures are too small to track using bulky radio tags.


Now miniaturised gadgets have allowed a team from GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany, the Turtle Foundation and Queen Mary University of London to shed more light on the first days of a turtle's life.


The team tagged hatchlings with the turtle equivalent of Fitbits, wearable data-measuring devices, before observing them for several days in a pool (see picture above). After an initial 24-hour swim, they switched to an active daytime routine, followed by chilled-out nights.


Night-time relaxation isn't typical for their American cousins, so the researchers wondered if offshore currents could provide an explanation for the relaxed behaviour. Currents in the islands pass close to the turtles' birthplace, carrying them away from coastal predators and into the safety of the open sea.


They used 12-millimetre-long tags (see picture, below) to track hatchlings during their maiden swim. They found that the babies made a beeline for the ocean currents before taking it easy, letting the currents whisk them away at up to 60 metres per minute.


(Image: Rebecca Scott, GEOMAR)


Journal reference: Proceedings of the Royal Society B DOI: 10.1098/rspb.2014.1209


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