Scientists from Queen Mary, University of London have tracked bumblebees for the first time to see how they select the optimal route to collect nectar from multiple flowers and return to their nest.
In a paper published in PLOS Biology today (18 September), the scientists, working with the Harmonic Radar Group at Rothamsted Research, were able to use radar tracking to show how bumblebees discover flowers, learn their location and use trial and error to find the most efficient route between flowers over large distances.
Professor Lars Chittka and Dr Mathieu Lihoreau from Queen Mary's School of Biological and Chemical Sciences and colleagues set up five artificial flowers in a 1km diameter field. Each flower was fitted with motion-triggered webcams and had landing platforms with drops of sucrose in the middle*.
"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," Dr Lihoreau explained.
"But, as they gained experienced, 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."
Professor Chittka and colleagues have previously shown that bees were able to learn the shortest route possible to navigate between flowers in the lab but this is the first time they have been able to observe this behaviour in natural conditions and to describe how bees may optimise their routes.
"The speed at
|Contact: Bridget Dempsey|
Queen Mary, University of London