5. Tracking and Transmitters
Satellite tracking studies have revealed the direct route that individuals take back to Brazil, a trip that takes some six weeks. Here algae are plentiful and the turtles feed until they have enough fat reserves to sustain the migration to and from Ascension Island and to produce their clutches of eggs. We do not know how the turtles find Ascension Island, but theories range from olfactory (smell), visual and auditory (sound) cues, to innate maps and magnetic fields. Recent work on Ascension, with females being displace offshore with satellite transmitters attached have suggested that, at least a few hundred kilometres away, the turtles may be able to smell the island downwind. Until recently, it was assumed that the males, which are smaller than the females with a long tail) also live in Brazil. In 2000 this was confirmed when 2 male turtles were tracked using satellite transmitters.
Mail Rob and Julia in Ascension Island!
Last revised on the 21st of April 2002 by Stephen Fowler.