The role of the avian hippocampus in spatial memory

Avian hippocampal function is surveyed, using data drawn from three areas:
 conventional laboratory paradigms, pigeon navigation, and food-storing.
 Damage to the avian hippocampus disrupts performance in laboratory tasks
 that tap spatial learning and memory, and also disrupts both pigeon homing
 and cache recovery by food-storing birds. Further evidence of hippocampal
 involvement in food-storing is provided by the fact that the hippocampus of
 food-storing birds is selectively enlarged. These findings lend support to the
 notion that the hippocampus plays a critical role in spatial learning and
 memory. However, avian hippocampal lesions (like mammalian
 hippocampal lesions) also disrupt certain laboratory tasks that do not have
 an overt spatial component. Moreover, analysis of the effects of
 hippocampal lesions on navigation find, first, that basic navigational
 processes are left intact, and second, that at least some of the disruption of
 homing may be caused by disruption of the associability of information
 derived from the sun compass - a non-spatial deficit. Finally, attempts to
 demonstrate that the enlarged hippocampus of food-storing birds is associated
 with enhanced spatial memory have failed to deliver conclusive support. The
 extensive parallels between effects of hippocampal lesions in birds and
 mammals suggest that both the spatial and the non-spatial deficits form part
 of a single syndrome, one that cannot readily be explained in terms of
 disruption of specifically spatial processes