Peter Reuell in the Harvard Gazette:
Navigating a cluttered environment at high speed is among the greatest challenges in biology. Yet it’s one virtually all birds achieve with ease.
It’s a feat that David Williams is working to understand. A former postdoctoral fellow in the Harvard lab of Charles P. Lyman Professor of Biology Andrew Biewener, and now a postdoc at the University of Washington, Williams is the lead author of a study that shows birds use two highly stereotyped postures to avoid obstacles in flight.
The study could open the door to new ways to program drones and other unmanned aerial vehicles to avoid similar obstacles. The study is described in a paper recently published in the Proceedings of the National Academy of Sciences.
“This was somewhat surprising to us,” Williams said of the results. “In lower-order animals like insects, we think of these very stereotyped motor programs where you stimulate your muscle, and the passive dynamics of your exoskeleton or the tendons attached to that muscle control most of the motion.
“But when you look at higher-order animals, it’s common to expect that those motor programs are going to be more complex, and there’s going to be more subtle gradations in those programs. So it was surprising to see a very high-order animal like a bird using very simple motor programs. Biology is optimized to be just good enough to work, so what that indicates is those are very effective motor programs.”