Comment »Posted on Tuesday 12 May 2009 at 5:07 pm by Jessica Bland
In Biology, Evolution, Physics

Like Jacob, I wrote for two outlets. It’s quite interesting to see how the story changes almost entirely for each outlet. 

For British Beekeepers Association News…

Bumblebee flight continue to astound scientists

There is an old myth that bumblebees shouldn’t be able to fly. The maths just doesn’t work. A new study from scientists at Oxford University shows that bumblebee flight is indeed more about power than finesse.

The researchers trained bees to fly along a wind tunnel erected between their hive and pollen-rich cut flowers. Smoke in the wind tunnel is disturbed by the flight, making visible the way that bees disturb the air around them. A high-speed camera captured the flight, and those images were analysed to develop a model for the motion of bees in flight.

The idea is very similar to the computer modelling used by swimmers to examine how efficient their stroke is through the water. But unlike athletes, bumblebees have not developed to move efficiently. In fact, the new study shows that the movement of air around the bee betrays a very uneconomical flying technique.

‘We found that bumblebee flight is surprisingly inefficient,” said Dr Richard Bomphrey, co-author of the report. He explained how a bee’s left and right wings do not flap in sync. And nor does the air flow around the two sides meet up, which would help make the flight more aerodynamic.

His colleague, Professor Adrian Thomas offered a possible reason for the evolution of such a disastrous technique: “a bumblebee is a tanker-truck, its job is to transport nectar and pollen back to the hive. Efficiency is unlikely to be important for that way of life.”

So the flight path between flower and hive resembles the slow lane on the M1 and not a quiet stretch of the Autobahn. But the brute force bees need to keep themselves going is spectacular in its own way. They are the powerhouses of the insect world, defying the mathematics that says they shouldn’t even get off the ground.

For Physicsworld…

Can bees teach us how to fly?

Scientists have shown that bumblebees use a unique technique to propel themselves through the air. In a study published in May in Experiments in Fluids, a team from the Zoology department in Oxford examined the air flow profile of a flying bee. The pattern of vortices created in the air surrounding the bee in novel.

Unfortunately, this novelty is unlikely to be useful for physicists and engineers interested in biomimetic developments in flight technology. The bee’s flying technique only makes it less efficient.

Like other insects and like aeroplane wings, a bumblebee creates a leading edge vortex during flight. It separates the air flow coming towards it at the front edge of its wings and flies by exploiting the resulting pressure difference above and below the wing.

But most insects also create other vortices, called root and tip vortices. The bee does not. Other insects and birds also co-ordinate right and left wing motion to maximise their propulsion. The bee does not do this either.

“We found that bumblebee flight is surprisingly inefficient,” said Dr Richard Bomphrey, co-author of the study. He added that the technique could have evolved to make bumblebees more manoeuvrable in the air – a facet that might be more valuable for bees than speed through the air.

So, although bees are inefficient flyers, their propulsion technique could be useful for research in other areas. If bees can be shown to have increased control over movement, then they offers a potential model for improving the control we have over airbound vehicles such as helicopters.

More research is needed before we can know if there is any application. But there is a possibility that the bumblebee, the famous example of an animal that flouts the engineering principles of flight, could help us improve our air technology.

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