Understanding the flight of the bumblebee

September 20, 2012
Image credit: Wikipedia.

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 September 18 in the open access journal , the scientists, working with the Harmonic Radar Group at Rothamsted Research, were able to use radar tracking to show how bumblebees discover , 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 , and colleagues set up five in a 1km diameter field. Each flower was fitted with motion-triggered webcams and had landing platforms with drops of in the middle.

"Using mathematical models, we dissected ' 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 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."

To keep the bees' focus on the artificial flowers, the experiments were done in October, when of and pollen were scarce. To make the bees want to find all five flowers, each sucrose drop was only enough to fill one fifth of a bumblebee's crop. And to keep the bees from finding one foraging site from another visually, the flowers were arranged in a pentagon that was 50 m on each side, which is more than three times as far as bumblebees can see.

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 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," Professor 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."

The scientists used motion-triggered webcams and tiny bumblebee-mounted radar transponders to track the . The recordings on the flowers showed that bees exhibited considerable individuality—each one had a favoured arrival and departure direction, different from the other bees.

Head of Computational and Systems Biology at Rothamsted Research, Professor Chris Rawlings, added: "This is an exciting result because it shows that seemingly complex behaviours can be described by relatively simple rules which can be described mathematically.

"This means we can now use mathematics to inform us when bee behaviour might be affected by their environment and to assess, for example, the impact of changes in the landscape."

Explore further: The cost of long tongues

More information: Lihoreau M, Raine NE, Reynolds AM, Stelzer RJ, Lim KS, et al. (2012) Radar Tracking and Motion-Sensitive Cameras on Flowers Reveal the Development of Pollinator Multi-Destination Routes over Large Spatial Scales. PLoS Biol 10(9): e1001392. doi:10.1371/journal.pbio.1001392

Related Stories

The cost of long tongues

April 16, 2007

Orchid bees use their extraordinarily long tongues to drink nectar from the deep, tropical flowers only they can access. Researchers have long suspected that this kind of exclusive access came with a mechanical cost.

Smells like bees' spirit

August 13, 2008

Bumblebees choose whether to search for food according to how stocked their nests are, say scientists from Queen Mary, University of London.

How bumblebees tackle the traveling salesman problem

June 29, 2011

It is a mathematical puzzle which has vexed academics and travelling salesmen alike, but new research from Queen Mary, University of London's School of Biological and Chemical Sciences, reveals how bumblebees effectively ...

Making a bee-line for the best rewards

August 17, 2011

Bumblebees use complex problem solving skills to minimise the energy they use when flying to collect food, according to new research from Queen Mary, University of London.

Recommended for you

Research advances on transplant ward pathogen

August 28, 2015

The fungus Cryptococcus causes meningitis, a brain disease that kills about 1 million people each year—mainly those with impaired immune systems due to AIDS, cancer treatment or an organ transplant. It's difficult to treat ...

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

Rare nautilus sighted for the first time in three decades

August 25, 2015

In early August, biologist Peter Ward returned from the South Pacific with news that he encountered an old friend, one he hadn't seen in over three decades. The University of Washington professor had seen what he considers ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.