Encoding spatial information in the waggle dance.

Apis mellifera bees execute waggle dances to recruit other bees to desirable food sources. Several components of the waggle dance are correlated with the direction of and the distance to food. Moreover, recruits use the spatial information encoded in the dance to locate the signalled food. However, although dance communication has been studied extensively, little is known about how the dancers combine the compass (direction) and the odometric (distance) information they acquire during the foraging flight. In the present study, we analysed the encoding of spatial information in the waggle dance by manipulating the navigational information provided to dancing bees. To this end, we took advantage of the bees' visually driven odometer. We found that the waggle dance basically encodes information on the distance gauged during the outbound (hive-to-food) flight. However, it does not necessarily refer to a global vector based on path integration of the outbound flight. Whenever the direction connecting the subjective food location and the hive does not match the direction of the global vector, dancers refer to a direction close to that of the shortcut connecting the actual food location and the hive. Moreover, in our experiments, this direction was close to that of the inbound (food-to-hive) flight, indicating that landmark-based information is computed during the inbound flight and that it may strongly affect the encoding of directional information in the waggle dance. Moreover, we found that the bees' experience of the terrain modulates the encoding of spatial information in the waggle dance, suggesting that interactions between path integration and visual landmarks are computed in the context of dance communication.