Meeting Abstract
Bumblebees forage in windy, unpredictable environments where they must make decisions about how to reach certain resources. Wind conditions likely affect their flight paths and foraging efficiency. In natural environments, bees are often confronted with headwinds or tailwinds, yet little attention has been paid to whether bees choose flight routes based on wind direction. We allowed a colony of Bombus vosnesenskii to forage in a dual-channel wind tunnel with small fans in both channels, and with the nest box and nectar source at opposite ends. We altered wind conditions daily in the two channels and observed foraging behavior with no wind, with 1.25 m/s wind in opposite directions in each channel, or with 1.1 m/s wind in one channel and no wind in the other. We used two high speed cameras above the tunnel to collect 1.2 s of video per minute over two hours, for fourteen days. We tracked all bees in each video, providing us with the location, direction, and speed of each bee. Bees showed no preference for either side of the dual-channel wind tunnel. However, we found that bees exhibited a significant preference for flying upwind vs. downwind, choosing the channel that allowed them to fly upwind approximately twice as often. Flying upwind requires an increase in thrust production while a tailwind adds to the bee’s forward speed, suggesting that downwind flight should be easier; but previous work has shown that bees can increase their forward speed with little metabolic cost, whereas they struggle to maintain stability when flying with a tailwind. Along with our findings that bees prefer to fly upwind, this suggests that maintaining stability is a major consideration for bees in flight, and that flying with a tailwind may be an overlooked flight challenge in natural, windy environments.
