The use of relative and absolute bearings by Clark's nutcrackers, Nucifraga columbiana

Two groups of Clark's nutcrackers were trained to find buried seeds whose l ocation was defined by a constant angle from two landmarks whose interlandm ark distance and position in the room varied across trials. The first group had a landmark array that was always placed in the same orientation with r espect to the walls, allowing the animals to use both relative and absolute bearings. The second group had a landmark array that rotated across trials so that only relative bearings could be used to locate the seeds. The bird s in each group learned the task and transferred to new interlandmark dista nces both within and beyond the range of training distances. Results from t hese experiments indicate that nutcrackers can learn a geometric relationsh ip that relies exclusively on relative bearings even though the use of abso lute bearing yields more efficient search.