A Common Frame of Reference for Learned and Communicated Vectors in Honeybee Navigation

Humans draw maps when communicating about places or verbally describe routes between locations. Honeybees communicate places by encoding distance and direction in their waggle dances [1]. Controversy exists not only about the structure of spatial memory but also about the efficiency of dance communication [2-5]. Some of these uncertainties were resolved by studies in which recruits' flights were monitored using harmonic radar [6, 7]. We asked whether the two sources of vector information-the previously learned flight vector to a food source and the communicated vector-are represented in a common frame of spatial reference. We found that recruits redirect their outbound flights and perform novel shortcut flights between the communicated and learned locations in both directions. Guidance by beacons at the respective locations or by the panorama of the horizon was excluded. These findings indicate a spatial reference based on either large-scale vector integration or a common geocentric map-like spatial memory. Both models predict a memory structure that stores the spatial layout in such a way that decisions are made according to estimated distances and directions. The models differ with respect to the role of landmarks and the time of learning of spatial relations.