Bumblebees use 'trial and error' method to find optimal route

 Scientists have discovered that bumblebees use the 'trial and error' method to select the optimal route to collect nectar from multiple flowers and return to their nest.

Researchers from the Queen Mary, University of London 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.

The study set up five artificial flowers in a 1 km 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," researcher Dr Mathieu 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," Lihoreau said in a statement.

"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," Lihoreau said.

"The speed at which they learn through trial and error is quite extraordinary for bumblebees as this complex behaviour was thought to be one which only larger-brained animals were capable of," researcher Professor Lars Chittka said.

"Interestingly, we also found that if we removed a flower, bees continued looking at that location - even if it was empty for an extended period of time. It seems bees don't easily forget a fruitful flower," Chittka said.