Interactions of visual odometry and landmark guidance during food search in honeybees

Abstract

How do honeybees use visual odometry and goaldefining landmarks to guide food search? In one experiment, bees were trained to forage in an optic-flowrich tunnel with a landmark positioned directly above the feeder. Subsequent food-search tests indicated that bees searched much more accurately when both odometric and landmark cues were available than when only odometry was available. When the two cue sources were set in conflict, by shifting the position of the landmark in the tunnel during test, bees overwhelmingly used landmark cues rather than odometry. In another experiment, odometric cues were removed by training and testing in axially striped tunnels. The data show that bees did not weight landmarks as highly as when odometric cues were available, tending to search in the vicinity of the landmark for shorter periods. A third experiment, in which bees were trained with odometry but without a landmark, showed that a novel landmark placed anywhere in the tunnel during testing prevented bees from searching beyond the landmark location. Two further experiments, involving training bees to relatively longer distances with a goal-defining landmark, produced similar results to the initial experiment. One caveat was that, with the removal of the familiar landmark, bees tended to overshoot the training location, relative to the case where bees were trained without a landmark. Taken together, the results suggest that bees assign appropriate significance to odometric and landmark cues in a more flexible and dynamic way than previously envisaged.

Wind alters landing dynamics in bumblebees

“…It is also possible that olfaction plays a role in restricting landing angles, as scents emitted from the flowers could be carried downstream, exposing bees to olfactory cues. However, given that bees are known to rely strongly on visual cues when in close proximity to a floral stimulus (Srinivasan et al, 2000; Vladusich et al, 2005;Lunau, 1992), we believe that olfaction plays only a minor role (if any) in our results. The restriction of bumblebee landing angles in wind observed here may have important consequences for the ecomechanics of pollination.…”

Depth, contrast and view-based homing in outdoor scenes

“…These observations demonstrate that the insects do not only memorize individual salient features, but also the wider visual context in which they are seen. A number of other observations support this conjecture: bees that have been trained to fly through a narrow textured tunnel to find a food source some distance into the tunnel, do not fly beyond a novel overhead object (landmark) that is introduced during tests (Vladusich et al 2005); the visual environment of waterstriders has to be reduced to a single overhead point of light, before their ability to maintain their position on a flowing water surface is compromised (Junger 1991); the homing ability of stingless bees is affected when the apparent position of distant landmarks beyond the nest and to the side of their normal flight path is changed (Zeil and Wittmann 1993). Although experiments such as these do suggest that at least insects do memorize the panoramic view of their environment, direct evidence is still lacking.…”

Honeybee Communication and Pollination

“…In essence, both sides of the "controversy" agree that odor is used in recruitment to resources, but they differ strongly in opinion as to the information content of the dance. Honeybees also have the cognitive ability to visible recognize and learn landmarks for their food sources (Vladusich et al, 2005).…”