“Flight of the Bumblebee”

I always wanted to learn to play this piano solo by Rimsky-Korsakov well as a kid, but never achieved any speed, so my version of the “bumblebee” was more of a speedy snail.

Biologically, the flight of the bumblebee is a complicated thing, produced by opposing sets of muscles in their thorax that not only power flight, but more importantly — generate heat to keep the thorax (and the muscles) warm.

Common eastern bumblebee on Dahlia-

I was surprised to find several Common Eastern Bumblebees on just the white Dahlias this morning when the temperature was a chilly 40 F.  But I shouldn’t have been. Read on…

As it turns out, bumblebees are as fussy about their core operating temperature as humans and race cars are, yet they can fly (and forage) over a wide range of air temperatures from freezing (0 C) to a very warm 35 C (95 F), remarkably regulating their thoracic temperature somewhere in the neighborhood of 30-35 C (85-95 F). Why do they bother?  Because muscles work more powerfully and efficiently when they are warm.

Common eastern bumblebee on Dahlia-

Short dense hairs cover the entirety of the bee’s thorax and provide some insulation to retard heat loss.  There must have been some reward buried deep in that clump of anthers, judging from the amount of time they spent probing there.

Thus, on crisp fall mornings, you might still find bumblebees active on your flowers, perhaps walking a little sluggishly around the nectaries or stamens, but then miraculously buzzing off to the next flower some distance away.  If you watch closely, you might see them pause, motionless for a minute or two prior to departure, while they execute a pre-flight warm-up.

Common eastern bumblebee on Dahlia-

Ready for take-off, perched on the edge of the Dahlia, motionless with wings spread out.  I heard the buzz as the bee flew up over my head, but I wasn’t fast enough to catch it in flight.

However, they don’t shiver their wings the way moths do as they warm up — in fact, there is no noticeable movement of bumblebee wings at all before take off. Sitting motionless, like a plane waiting to taxi up to the end of the runway while revving its engines, those opposing sets of thoracic muscles are in fact building internal tension and releasing heat — kind of an isometric exercise. Ingeniously, a third set of thoracic muscles unhinges the connection between flight muscles and wing joints, letting the thoracic engine rev in neutral with the clutch in until optimal temperature is reached.  Relaxing that third muscle lets the clutch out and engages the flight muscles in wing movement again — and off the bee goes.

And that is a lengthy explanation of why we still see bees in the garden foraging on the remaining flowers on frigid fall mornings.

For a little change of pace, you can watch a 7 year old boy make his fingers fly at the speed of sound while playing “Flight of the Bumblebee” in Australia’s Got Talent show. Skip to 1:50 in the video to view (hear) him actually playing.

4 thoughts on ““Flight of the Bumblebee”

  1. Great information, Sue, about the bees. I love the image of the bees preparing for takeoff like a jet. I wonder if they have a pre-flight checklist. As our temperatures continue to drop, I’ll keep an eye out for those behaviors that you illustrate so beautifully in your images.

    • thanks, Mike. I was confused by their resting behavior, thinking they were too cold to fly, and thought they were just sitting there basking in the sunshine. It certainly makes sense that they wouldn’t wait for passive heat absorption to warm them enough to fly — that would take way too long. It’s a pretty impressive system — clever bees!

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