For decades, scientists unfairly maligned the humble butterfly as an inefficient creature. Now, with the help of a wind tunnel, scientists in Sweden are proving the opposite is true.
In the early 1970s scientists first noticed the insect claps its wings during flight. At first, the discovery seemed to help cement the creature’s reputation as a clumsy flier. But Swedish scientists on Jan. 20 published a paper in the Journal of the Royal Society Interface showing slapping its wings at the top of the upstroke helps the butterfly produce forward thrust by capturing a pocket of air and jetting it backwards. The discovery demonstrates that, far from being inefficient flyers, butterflies are fearfully and wonderfully made.
Biologists Christoffer Johansson and Per Henningsson of Sweden’s Lund University began by catching six silver-washed fritillary butterflies in a meadow near their Stensoffa, Sweden, field station. The pair of scientists hoped to use a wind tunnel to monitor how the butterflies use their flexible wings to create thrust and lift. But in order to study butterfly aerodynamics, the team needed to see the air interacting with the insects’ wings. By releasing visible gas called a tracer into the wind tunnel, the team could observe the butterflies creating vortices or even capturing pockets of air with their wing flaps. “When the wings clap together at the end of upstroke the air between the wings is pressed out, creating a jet, pushing the animal in the opposite direction,” the scientists wrote in their report.
A fluttery flying technique https://t.co/vZ2SsYprEv
— Arugula Santiago (@ArugulaSantiago) February 5, 2021