Do yellow-pine chipmunks prefer to recover their own caches

Many rodent species scatter hoard seeds within a home range shared with other seed-caching animals. An animal foraging for cached food is likely to encounter the caches of other animals, as well as its own. This study asks the following question: do animals recover primarily their own caches, do they conserve their own caches and search for the caches of other animals, or do they search indiscriminately for cached seeds regardless of who buried them? We tested these ideas using 8 yellow-pine chipmunks inside rodent-proof enclosures. We allowed each subject to cache radioactive seeds, we located the seed caches, and then we paired each rodent cache with an artificial cache in a similar microsite. During search trials, 7 subjects removed mostly their own caches, and 1 subject removed similar numbers of its own caches and paired artificial caches. These results suggest that most yellow-pine chipmunks actively search for food that they have stored, apparently using spatial memory rather than relying on olfaction. However, previous studies have established that chipmunks also are very effective pilferers of caches made by other animals. This apparent discrepancy may result from a difference between enclosures and field sites in the proportion of “own” caches to total caches.