Honeybees (Apis mellifera) Remember Two Near-Target Landmark Constellations

A set of experiments tested whether honeybees can remember two different landmark constellations within the same room, or whether the two constellations are mixed together in a single composite memory. Bees were trained to find a reward location with two different landmark arrays. For example, when the blue landmark was north of the yellow one, the reward was to the east; when the yellow landmark was north of the blue one, the reward was to the west. On occasional unrewarded tests, either one of the training arrays was presented (control tests), or else a training array rotated by 90° (rotated tests). A rotated array consisted of part of one training array added to a part of the other training array. Should honeybees form a single composite memory by combining the two training arrays, they should search as much at the target location on rotated tests as on control tests. Results refute this and suggest that they had two separate memories.