RUFOUS HUMMINGBIRDS (SELASPHORUS-RUFUS) MEMORY FOR FLOWERS - PATTERNSOR ACTUAL SPATIAL LOCATIONS

Two field experiments were performed to examine the use of absolute an d relative spatial cues by foraging rufous hummingbirds (Selasphorus r ufus). Presented with 5 flowers arranged in a cross, birds learned tha t only the center flower was rewarded. When the array was shifted, bir ds returned to the relative center of the array when flowers were clos ely spaced but to the absolute location of the reward when spacing was greater than 40 cm. In Experiment 2, a 16-flower array was used, spac ed either at 10 or 80 cm. Flowers were either visually identical or di fferent, and 8 were rewarded with sucrose. Birds learned the rewarded locations more quickly when flowers were visually different. When the arrays of flowers were moved, performance was independent of flower vi sual patterns. At 10-cm spacing, birds tended to use relative location to recall rewarded flowers but used absolute location at 80-cm spacin g.