Honeybee Odometry: Performance in Varying Natural Terrain

Abstract

Recent studies have shown that honeybees flying through short, narrow tunnels with visually textured walls perform waggle dances that indicate a much greater flight distance than that actually flown. These studies suggest that the bee's “odometer” is driven by the optic flow (image motion) that is experienced during flight. One might therefore expect that, when bees fly to a food source through a varying outdoor landscape, their waggle dances would depend upon the nature of the terrain experienced en route. We trained honeybees to visit feeders positioned along two routes, each 580 m long. One route was exclusively over land. The other was initially over land, then over water and, finally, again over land. Flight over water resulted in a significantly flatter slope of the waggle-duration versus distance regression, compared to flight over land. The mean visual contrast of the scenes was significantly greater over land than over water. The results reveal that, in outdoor flight, the honeybee's odometer does not run at a constant rate; rather, the rate depends upon the properties of the terrain. The bee's perception of distance flown is therefore not absolute, but scene-dependent. These findings raise important and interesting questions about how these animals navigate reliably.

Visual working memory in decision making by honey bees

“…Thus, when the trained bees are confronted with two sample stimuli, one at the training distance and the other at a different (unfamiliar) distance, they treat the stimulus at the familiar distance as the ''true'' sample stimulus and deem the other stimulus to be irrelevant. Recent work has shown that bees estimate distance flown in terms of the image motion that they experience en route (34)(35)(36)(37)(38)(39). In our experiments, however, the walls and floor of the tunnel were devoid of any visual texture, thus precluding accurate measurement of image motion.…”

Cognition in Invertebrates

“…The length of the single waggle-runs increases with the distance flown to reach the source, and their angles relative to gravity correlate with the direction of the foraging flights relative to the sun's azimuth in the field and sun-linked patterns of polarized skylight. Thus, by encoding the visually measured distance (Esch and Burns, 1995;Srinivasan et al, 2000a;Tautz et al, 2004) and the direction toward the goal, the waggle dance allows colony members to share information about the distance and direction toward a desirable goal (von Frisch, 1967;Seeley, 1995;Dyer, 2002). Although Karl von Frisch used the term ''dance language,' ' Premack and Premack (1983) correctly stated that the honeybee dances should not be called a language, based on the argument that there is no evidence that the bees can judge whether their dances conform to anything in their surroundings.…”

“…Thus, one might ask whether the waggle dance encodes spatial information provided only by the actual flight path. The role of landmarks so far has been considered only in the context of resetting (Srinivasan et al, 2000b) or calibrating the odometer (Tautz et al, 2004) but not in the communicative process. The detour experiments by von Frisch suggest that the directional component reported in the waggle dance may also be derived from stored path integration coordinates of visually defined locations (landmarks).…”

Optic Flow Based Visual Guidance: From Flying Insects to Miniature Aerial Vehicles

“…They were rescued from drowning only when the water surface was rippled or when a slatted bridge was placed on the water surface to provide sufficient contrast (Heran & Lindauer, 1963). Recent studies on bees trained to fly across a lake did not quite confirm these early results (Tautz et al, 2004), but the (large) lake may not have been as ripple-free as the (small) flooded quarry used in the original experiments. A featureless expanse of water no longer provides the animal's eye with any contrasting features, and the OF sensor will no longer respond.…”