Clark's nutcracker spatial memory: The importance of large, structural cues

• Clark's nutcrackers cache in habitats with heavy snowfall and potential disturbance of local landmarks.
• In captivity, Clark's nutcrackers were more accurate when recovering cached food in a small than in a large room.
• Adding freestanding landmarks or a set of dividing panels did not markedly help nutcrackers to find their caches in the large room.
• Nutcrackers seem to use structural features of rooms as important spatial cues.

Clark's nutcrackers, Nucifraga columbiana, cache and recover stored seeds in high alpine areas including areas where snowfall, wind, and rockslides may frequently obscure or alter cues near the cache site. Previous work in the laboratory has established that Clark's nutcrackers use spatial memory to relocate cached food. Following from aspects of this work, we performed experiments to test the importance of large, structural cues for Clark's nutcracker spatial memory. Birds were no more accurate in recovering caches when more objects were on the floor of a large experimental room nor when this room was subdivided with a set of panels. However, nutcrackers were consistently less accurate in this large room than in a small experimental room. Clark's nutcrackers probably use structural features of experimental rooms as important landmarks during recovery of cached food. This use of large, extremely stable cues may reflect the imperfect reliability of smaller, closer cues in the natural habitat of Clark's nutcrackers.This article is part of a Special Issue entitled: CO3 2013.