DIFFERENTIAL MEMORY FOR DIFFERENT CACHE SITES BY CLARKS NUTCRACKERS (NUCIFRAGA-COLUMBIANA)

When Clark's nutcrackers (Nucifraga columbiana) recover their caches, accuracy declines as recovery proceeds. Two experiments investigated this phenomenon. The results of Experiment 1 demonstrated that this effect is eliminated when the birds are forced to recover their caches in random order over several recovery sessions. This is consistent with the hypothesis that the decline in recovery accuracy is due to differential memory for different cache sites, with better remembered sites recovered first. During Experiment 2, nutcrackers were forced to use the same sites during successive cache recovery tests. There was no correlation between the orders of recovery in the 2 tests. This indicates that order of cache recovery is not determined by inherent physical characteristics of cache sites.