Cognitive Ecology of Food Hoarding: The Evolution of Spatial Memory and the Hippocampus

Many animals cache food when it is abundant and later rely in part on spatial memory to retrieve those caches. The importance of memory for cache recovery and fitness in food-caching species has been hypothesized to result in selection favoring enhanced spatial memory and an enlarged hippocampus, an area of the brain involved in spatial memory. This review aims to provide an overview of research investigating adaptive variation in memory, the hippocampus, and food hoarding; to identify the pitfalls of previous approaches; and to provide suggestions for future directions. Given the relatively low phylogenetic diversity of scatter-hoarding taxa, we advocate using a single-species, multipopulation approach to track evolutionary changes related to dependence on food caching for survival as a function of differences in the environment. We conclude that existing evidence strongly supports the hypothesis that spatial memory and its underlying neural mechanisms respond to selection pressures associated with scatter-hoarding food.