How do you go about discovering the way that bumblebees find their paths? By strapping tiny radar transponders to them, and tracking them via motion-activated webcams, of course.
A group of researchers from Queen Mary University of London did just that, setting up artificial flowers with webcams for the transponder laden bumblebees to visit, allowing scientists analyze how the insects found the most efficient paths to and fro. What they discovered is that the bees relied on repeated trial and error to find the shortest route. As study author Mathieu Lihoreau explains via press statement:
Using mathematical models, we dissected bees' learning process and identified how they may decipher this optimal solution without a map. Initially, their routes were long and complex, revisiting empty flowers several times. But, as they gained experience, the bees gradually refined their routes through trial and error.
Each time a bee tried a new route it increased its probability of re-using the new route if it was shorter than the shortest route it had tried before. Otherwise the new route was abandoned and another was tested. After an average of 26 times each bee went foraging, which meant they tried about 20 of the 120 possible routes, they were able to select the most efficient path to visit the flowers, without computing all the possibilities.
The bumblebees were able to learn remarkably quickly, at a speed thought reserved for animals with larger brains. The researchers were also able to map this behavior mathematically and believe that it shows how small-brained animals can solve complex routing problems using simple methods.
Image: A bumblebee (Bombus terrestris) worker with a transponder attached to its back, visiting an oilseed rape flower. Tracking bees with radar shows how they find an optimal route between multiple flowers. (Image credit: Andrew Martin.)