Wild, free-living hummingbirds can learn what happened, where and in which context

Studies in the laboratory have shown that animals can combine multiple kinds of information to form integrated memories for rules and events. Less is known about how animals make use of these integrated memories in the wild. Here we tested whether wild, free-living, rufous hummingbirds, Selasphorus rufus, could learn to identify rewarded flowers in a naturalistic foraging situation, by remembering, over multiple exposures, what flower was rewarded, where and in which context. Birds were presented with boards on which four artificial flowers were mounted, one containing a food reward, the others containing water. Which flower (its colour and location) contained a reward was indicated in one condition by the presence of visually distinctive background boards and in a second condition by the sequential order in which the boards were presented. In both conditions, birds combined these pieces of information and learned to use the context to determine which of the four flowers was rewarded. Although they were not required to do so here, it is possible that these birds might be able to combine pieces of information to form integrated memories for single events.