Can bumblebees fly? Obviously, they can, but how do they do it?
Calculations based on fixed-wing studies or simplified linear oscillating airfoil wings fail to show how enough lift can be generated to get the huge mass of a bumblebee, compared to its wing size, off the ground. But bumblebee wings are moving, not fixed. They are also not simple airfoils like an airplane wing, and they don’t move in a simple way. Bumblebees actually have four wings. As the wings move, they bend and create air flow separation and an effect called dynamic stall creating a large air vortex above the wing. These vortices provide great lift with minimal energy.
But don’t think that the flight of the bumblebee doesn’t take much energy. The flight muscles which power the wings take up almost the entire volume of the thorax, the mid-section of the bee. The buzzing you hear is not the beat of the wings, but the pulsing vibration of the powerful flight muscles.
The bumblebee can’t fly unless its wing muscle temperature is at least 30 degrees C (86 degrees F). When the surrounding temperature is cooler, the bumblebee shivers to raise its muscle temperature before it can take off. Depending on air temperature and the bee’s temperature (such as from sitting in the sunshine) it may take from a few seconds up to 15 minutes to reach takeoff temperature. In the meantime, the bee is sort of sitting on the runway waiting for clearance.
The enormous complexity of the motion, the design of the wings, and the support system that moves the wings all speak of highly planned and designed structures. We can see the wisdom of design in even the smallest of God’s creatures.
© Roland Earnst
Photo Credit: © bigstockphoto.com/natburr