Search for a hidden goal by Clark's nutcrackers (Nucifraga columbiana) is more accurate inside than outside a landmark array

In three experiments in which an open-room delayed response task was used, we explored how Clark's nutcrackers use landmarks to search for a hidden goal when multiple potential goal locations were present. In Experiment 1, nutcrackers presented with three spatial samples were able to use relative local cues from an array that changed positions throughout a session to return to a hidden goal during a test. In Experiment 2, the number of samples varied from one to three prior to the test. The nutcrackers performed as well with one sample as with two or three samples. In Experiment 3, we attempted to increase the cost of searching for the goal but, in contrast to previous reports with nutcrackers, found no improvement in search accuracy. Across all experiments, search accuracy varied reliably for different goal locations, but the pattern of performance at each location was generally consistent. This result suggests that nutcrackers may be using different types of spatial information, depending on goal-landmark relationships.