A study published Monday revealed that bumblebees exchange maneuverability for stability when they change their load from nectar to pollen.
The findings, published in the Proceedings of the National Academy of Sciences, are among the first to show how nectar and pollen impact the flight dynamics of bumblebees.
"The literature shows bumblebees can carry just about over half their body mass in pollen or close to their body mass in nectar," says Sridhar Ravi of the aerospace engineering department at RMIT University in Australia, according to Discovery News.
While the insect carries nectar inside its abdomen, the pollen is carried on its legs. Ravi and his colleagues, Andrew Mountcastle and Stacey Combes, figured that these different load positions would have an impact on how the insect flew.
The team hypothesized that the insect would have enhanced stability while carrying pollen, because the pollen would act as balancing weights at a distance from its body. However these weights would also slow down the insect's turning ability and make it harder for it to maneuver.
In contrast, researchers reasoned that bumblebees would experience enhanced maneuverability because their weight would be focused near their center of gravity.
In order to test their hypothesis, the team mail ordered a package of bees and put several of them, after affixing differing amounts of small steel ball bearings (acting as replacements for pollen and nectar), one by one into a miniature wind tunnel where wind and imitation flower targets were varied, according to Phys.org.
By filming the bees with high-speed cameras, the team was able to see how the bees adapted their flight patterns according to wind speed or how the flower was moved. Their hypothesis was proven correct upon seeing that bee flight was more stable when a bee carried a load of pollen, which proved advantageous during windy conditions but a detriment while flying in calm air.
The results indicate, according to the team, that bumblebees may actually choose between getting pollen or nectar depending on wind conditions. Their next step is to study their new hypothesis to see if it pans out.
