FN Archimer Export Format PT J TI The Role of Geomagnetic Cues in Green Turtle Open Sea Navigation BT AF BENHAMOU, Simon SUDRE, Joel BOURJEA, Jerome CICCIONE, Stephane DE SANTIS, Angelo LUSCHI, Paolo AS 1:1;2:2;3:5;4:6;5:3;6:4; FF 1:;2:;3:PDG-RBE-DOI;4:;5:;6:; C1 CNRS, CEFE, Montpellier, France. CNRS, LEGOS, Toulouse, France. Ist Nazl Geofis & Vulcanol, Rome, Italy Univ Pisa, Dipartimento Biol, I-56100 Pisa, Italy. IFREMER, La Réunion, France Kelonia, La Réunion, France C2 CNRS, FRANCE LEGOS, FRANCE INGV, ITALY UNIV PISA, ITALY IFREMER, FRANCE KELONIA, FRANCE SI LA REUNION SE PDG-RBE-DOI IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe IF 4.092 TC 18 UR https://archimer.ifremer.fr/doc/00048/15958/13390.pdf LA English DT Article AB Background: Laboratory and field experiments have provided evidence that sea turtles use geomagnetic cues to navigate in the open sea. For instance, green turtles (Chelonia mydas) displaced 100 km away from their nesting site were impaired in returning home when carrying a strong magnet glued on the head. However, the actual role of geomagnetic cues remains unclear, since magnetically treated green turtles can perform large scale (.2000 km) post-nesting migrations no differently from controls. Methodology/Principal Findings: In the present homing experiment, 24 green turtles were displaced 200 km away from their nesting site on an oceanic island, and tracked, for the first time in this type of experiment, with Global Positioning System (GPS), which is able to provide much more frequent and accurate locations than previously used tracking methods. Eight turtles were magnetically treated for 24–48 h on the nesting beach prior to displacement, and another eight turtles had a magnet glued on the head at the release site. The last eight turtles were used as controls. Detailed analyses of water masses-related (i.e., current-corrected) homing paths showed that magnetically treated turtles were able to navigate toward their nesting site as efficiently as controls, but those carrying magnets were significantly impaired once they arrived within 50 km of home. Conclusions/Significance: While green turtles do not seem to need geomagnetic cues to navigate far from the goal, these cues become necessary when turtles get closer to home. As the very last part of the homing trip (within a few kilometers of home) likely depends on non-magnetic cues, our results suggest that magnetic cues play a key role in sea turtle navigation at an intermediate scale by bridging the gap between large and small scale navigational processes, which both appear to depend on non-magnetic cues. PY 2011 PD OCT SO Plos One SN 1932-6203 PU Public Library Science VL 6 IS 10 UT 000296519600042 DI 10.1371/journal.pone.0026672 ID 15958 ER EF