Sea turtles compensate deflection of heading at the sea surface during directional travel.

摘要: SUMMARY Air-breathing marine animals, including sea turtles, utilise two fundamentally different environments (i.e. surface and underwater) during migration. Many satellite telemetry studies have shown travel paths at relatively large spatio-temporal scales, discussing the orientation navigation mechanisms that guide turtles. However, as obtained by only reflect movements surface, little is known about ability underwater. In this study, to assess both underwater, fine-scale 3-D of free-ranging loggerhead turtles Caretta caretta were reconstructed using multi-sensor data loggers. Video systems (‘Crittercam’) also used record behaviour visual information surrounding During August October in 2006 2007, eight released from Otsuchi Bay, Japan (39°20′30N, 141°56′00E), a total 118 h reconstructed. Turtles maintained highly straight-line courses (straightness index >0.95) 41% duration ‘travelling periods’). travelling periods, swam continuously, maintaining unidirectional heading throughout dives whereas changed remarkably surface. Despite directional dives, direction tended shift end lasting 10 minutes or more. Such deflections seemed be compensated subsequent surfacing periods because there was negative relationship between changes arising periods. Therefore, remarkable could interpreted direction-searching behaviour. Our results suggested undertaking more dependent on reliable