@article {Narazaki2009Sea,
	title = {Sea turtles compensate deflection of heading at the sea surface during directional travel},
	journal = {J Exp Biol},
	volume = {212},
	number = {24},
	year = {2009},
	month = {December},
	pages = {4019{\textendash}4026},
	abstract = {Air-breathing marine animals, including sea turtles, utilise two fundamentally different environments (i.e. sea surface and underwater) during migration. Many satellite telemetry studies have shown travel paths at relatively large spatio-temporal scales, discussing the orientation and navigation mechanisms that guide turtles. However, as travel paths obtained by satellite telemetry only reflect movements at the surface, little is known about movements and orientation ability underwater. In this study, to assess orientation ability both at the surface and underwater, fine-scale 3-D movements of free-ranging loggerhead turtles Caretta caretta were reconstructed by using multi-sensor data loggers. Video systems ( Crittercam{\textquoteright}) were also used to record the behaviour of the turtles and the visual information surrounding the turtles. During August and October in 2006 and 2007, eight turtles were released from Otsuchi Bay, Japan (39{degrees}20{\textquoteright}30N, 141{degrees}56{\textquoteright}00E), and a total of 118 h of 3-D movements were reconstructed. Turtles maintained highly straight-line courses (straightness index >0.95) during 41\% of the total duration (i.e. travelling periods{\textquoteright}). During travelling periods, turtles swam continuously, maintaining unidirectional heading throughout dives whereas turtles changed heading remarkably at the surface. Despite highly directional movements during dives, travel direction tended to shift by the end of dives lasting 10 minutes or more. Such deflections seemed to be compensated during subsequent surfacing periods because there was a negative relationship between changes in travel direction arising during dives and subsequent surfacing periods. Therefore, remarkable changes in heading at the surface could be interpreted as direction-searching behaviour. Our results suggested that turtles undertaking directional travel were more dependent on directional information that was reliable at the surface. 10.1242/jeb.034637},
	keywords = {migration, navigation, orientation, seaturtles},
	doi = {10.1242/jeb.034637},
	url = {http://dx.doi.org/10.1242/jeb.034637},
	author = {Narazaki, T. and Sato, K. and Abernathy, K. J. and Marshall, G. J. and Miyazaki, N.}
}
@article {WilzeckLearning,
	title = {Learning of magnetic compass directions in pigeons},
	journal = {Animal Cognition},
	year = {Submitted},
	abstract = {Abstract\&nbsp;\&nbsp;A proof of magnetic compass learning by pigeons under laboratory conditions has been attempted for decades, but all experiments have failed so far. The aim of the present study was to test whether pigeons can learn magnetic compass directions in an operant chamber if magnetic cues are presented as true spatial cues. Experimental sessions were carried out in the local geomagnetic field and in magnetic fields with matched total intensity and inclination, but different directions generated with Helmholtz-coils. Birds demonstrated successful learning with a performance level comparable to that in learning studies with magnetic anomalies. In addition, we compared the data from magnetic learning in the laboratory with performance from homing experiments in the field. The birds that were more successful in the learning experiment had vanishing bearings farther away from the home direction than the group mean at unfamiliar, but not at familiar sites. This might suggest that better learners explore unknown locations in a different way. Our findings represent the first evidence for operant magnetic compass learning in pigeons and also provide a link between behavioural data from the field and the laboratory.},
	keywords = {birds, migration, navigation, orientation, pigeons},
	doi = {10.1007/s10071-009-0294-0},
	url = {http://dx.doi.org/10.1007/s10071-009-0294-0},
	author = {Wilzeck, Christiane and Wiltschko, Wolfgang and G{\"u}nt{\"u}rk{\"u}n, Onur and Buschmann, Jens-Uwe and Wiltschko, Roswitha and Prior, Helmut}
}
