Honeybee navigation: flight strategies and the role of different landmark features

Acronym: 
BeeNaFF
Research Areas: 
A
Abstract: 

Honeybees use prominent landmarks to visually pinpoint the location of a food source, which makes them ideal model systems to study visual navigation. We explore the strategies bees use to localize their goal. By monitoring the bees flight behavior with high spatial and temporal detail, we investigate the behavioral relevance of different landmark features and the structure of the bees’ flight behavior, to find out how bees gain relevant visual information for recognizing and pinpointing the goal location.

 

Methods and Research Questions: 

Honeybees navigate repeatedly between feeding sites and their nest, seldom missing their goal. Once arrived close to the feeding site, they need to visually recognize and pinpoint the goal location. Bees have evolved efficient strategies to accomplish this task, which makes them ideal model systems to study visual navigation.

Although many studies have examined the role of visual memories in homing behavior there is currently no comprehensive view on what features of the visual scene are relevant for homing and how this information is encoded. Most authors assume that insects localize a goal by finding a close match between a memorized view at the goal location and their current view (“snapshot matching”).

Snapshot matching is often pictured as a static process, which involves stopping, comparing the current view with the memorized view at the goal, and then moving to increase the similarity between the views. In one subproject, we ask whether snapshot matching is indeed a static process and how the bees’ flight behavior – especially the fine structure of locomotion – relates to snapshot matching. In a second project, we investigate how bees combine and weight different landmark features when accomplishing navigational tasks. This project focuses on finding relevant features of landmarks that are memorized and their behavioral relevance.
By monitoring the bees flight behavior with high spatial and temporal detail, we investigate the structure of the bees’ flight behavior, to find out how honeybees actively gain relevant visual information for recognizing and pinpointing the goal location. The detailed analysis of the bee’s flight behavior gives insights into how snapshot matching might be accomplished and whether there is a hierarchy of landmark features that the bees use as cues for homing. In my project, I closely cooperate with Dr. Norbert Boeddeker, investigating active gaze strategies in bees, and Dr. Wolfgang Stürzl (CITEC project FLINAVS) working on the implementation of the bees' navigational strategies in simulations and robotic platforms.

 

Outcomes: 

Our results showed that static snapshot matching cannot explain all aspects of homing behavior as honeybees are able to use landmarks that are statically camouflaged. The bees used relative motion cues between the landmark and the background. These cues are generated on the eyes when the bee moves in a characteristic way in the vicinity of the landmarks. This extraordinary navigation performance can be explained by a matching scheme that includes snapshots based on optic flow amplitudes (“optic flow matching”). These results emphasize that snapshot matching is a dynamic rather than a purely static process.

The weighting of relevant visual information depends on the task and the saliency of the features. Honeybees used the spatial configuration of landmarks as the main cue for goal localization when trained with three landmarks of the same texture. However, when the near landmark had a unique texture (a “label”), the bees used texture cues to discriminate between the landmarks. It seems likely that honeybees select the relevant visual features adaptively depending on the task.

 

Publications: