S35-1 Spatial and object cognition in the domestic chicken

The ability of the chicken to encode different aspects of spatial layout were investigated. In a first series of experiments, chickens were disoriented in a rectangular environment, where they proved able to reorient themselves using both geometric and non-geometric properties of the environment. In a second series of experiments, chickens were trained to find the central position of an arena using only the spatial arrangement of the walls for orientation. When subsequently tested in an arena of identical shape but a larger area, chickens displayed searching behavior at two different distances, one corresponding to the original distance (i.e., center) in the smaller, training arena, the other to the actual center of the test arena. When training was performed in the presence of a conspicuous landmark at the center of the arena, animals searched at the central location even after the removal of the landmark. Chickens are thus able to encode information about absolute and relative distance from the walls of the arena, even when orientation by a single landmark suffices for spatial localization. Temporary occlusion of the left or the right eye during testing revealed that the right hemisphere (served by the left eye) is primarily concerned with encoding geometric and relational spatial information, whereas the left hemisphere (served by the right eye) is concerned with absolute metric information, possibly as part of an encoding strategy based on local spatial and non-spatial information.