Lateralized response of chicks to magnetic cues.

Previous research has shown that the ability to orient with the use of directional cues from the geomagnetic field is lateralized in three avian species: orientation is possible when the birds are restricted to use of their right eye, but not when they have to use their left eye. This has been interpreted as possible lateralization of the perception mechanisms for magnetic cues in favour of the right eye. Recent discovery of magnetic compass orientation in domestic chicks, a species in which lateralization has been well studied, has made available a model system in which to explore these lateralized processes more fully. Hence we tested chicks monocularly in the same test conditions as used previously to demonstrate the chick's use of a magnetic compass. In a magnetic field with North shifted by 90 degrees , chicks using their right eye oriented according to magnetic cues, whereas chicks using the left eye did not, but continued to prefer the original direction. Analysis of the times taken to respond indicated longer latencies in the chicks using their left eye, suggesting a possible conflict between cues. The different behaviour of the chicks using their left eye might not be a matter of a right eye-left hemisphere specialization for detecting magnetic directions, but of hemispheric specialization for attending to specific types of cues.