THE INFLUENCES OF LANDMARKS ON DISTANCE ESTIMATION OF HONEY-BEES

Honey bees, Apis mellifera, were trained to fly from their hive to a feeding site along a flight path marked by visually discriminable landmarks 3.46 m high. The landmarks were placed at regular intervals of 90 m. During training, the feeder was located directly in front of the third (target) landmark. In the tests, bees were given the choice of landing at the trained distance or at the target landmark which had been displaced to a different distance. Bees preferred to land at the target landmark when the discrepancy between the two indicated distances was small, but landed mostly at the trained distance if the discrepancy was large. Furthermore, distance estimation depended on landmarks encountered during flight. When the target landmark was placed at a distance from the hive closer than the trained distance, the bees' readiness to respond to this landmark could be increased only if bees had already passed the landmark that preceded the target landmark during training. Thus, a given flight goal is defined in the bees' memory by its distance from the hive, landmarks that mark the goal, and landmarks that precede the goal during flight. At the same time, the bees, as a group, exhibited considerable flexibility to land in places that were defined by only one or two of these cues. (C) 1995 The Association for the Study of Animal Behaviour