Marine turtles are renowned long-distance navigators, able to reach remote targets in the oceanic environment; yet the sensory cues and navigational mechanisms they employ remain unclear. Recent arena experiments indicated an involvement of magnetic cues in juvenile turtles’ homing ability after simulated displacements, but the actual role of geomagnetic information in guiding turtles navigating in their natural environment has remained beyond the reach of experimental investigations. In the present . experiment, twenty satellite-tracked green turtles (Chelonia mydas) were transported to four open-sea release sites 100-120 km from their nesting beach on Mayotte island in the Mozambique Channel; 13 of them had magnets attached to their head either during the outward journey or during the homing trip. All but one turtle safely returned to Mayotte to complete their egg-laying cycle, albeit with indirect routes, and showed a general inability to take into account the deﬂecting action of ocean currents as estimated through remote-sensing oceanographic measurements. Magnetically treated turtles displayed a signiﬁcant lengthening of their homing paths with respect to controls, either when treated during transportation or when treated during homing. These ﬁndings represent the ﬁrst ﬁeld evidence for the involvement of geomagnetic cues in sea-turtle navigation.
|Autori:||LUSCHI P; BENHAMOU S; GIRARD C; CICCIONE S; ROOS D; SUDRE J; BENVENUTI S|
|Titolo:||Marine turtles use geomagnetic cues during open-sea homing|
|Anno del prodotto:||2007|
|Appare nelle tipologie:||1.1 Articolo in rivista|