• visual lateralization
• sun compass
• spatial learning
• visual beacons
• homing pigeon

Functional asymmetries in the avian visual system have been observed in several tests with monocularly occluded birds. However, visual lateralization in sun compass-mediated spatial tasks has been poorly investigated. Monocularly occluded homing pigeons (Columba livia) have been tested in a food localisation task in an outdoor octagonal arena in order to investigate possible advantages of the left and right visual system in sun compass-based spatial learning. The two monocular and the binocular groups were trained to locate a food reward in the arena provided with a coloured beacon in each wall and tested after removing the visual cues. No significant difference has been found in test orientation between the three experimental groups, suggesting that both monocular and binocular groups were equally able to learn the task using sun compass information. However, pigeons using the left eye/right hemisphere were slower at learning than the other monocular group and their orientation was affected by the removal of the beacons, while the other two groups displayed unaltered performances during the test. Afterwards, a test was performed on a subsample of the three groups after a clock-shift treatment, which confirmed that all groups relied on sun compass to solve the task. The results suggested a possible advantage of the right hemisphere in relying on visual beacons but no hemispheric specialization in sun compass-based spatial learning.