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Unlike any other flying animal, butterflies have unusually short, broad and large wings relative to their body size. By studying the aerodynamics of butterflies in a wind tunnel, researchers have now answered this question which has confused lepidopterologists (who study moths and butterflies) for years.
Clap technique
The results suggested that butterflies use a clap technique which helps them take off rapidly. “When the wings clap together, the air between the wings is pressed out, creating a jet, pushing the animal in the opposite direction,” explains the paper published on Wednesday in the Journal of the Royal Society Interface. The flexible butterfly wings form a cupped shape during the upstroke and a clap that thrusts the butterfly forwards, while the downstroke is used for weight support.
Though butterflies exhibit a fluttery flight, they also perform highly directed and sustained flights during migration and take-off. Butterflies need high force and control for fast take-off flights. The team kept six individuals of silver-washed fritillaries (Argynnis paphia) in a wind tunnel and studied the behaviour and aerodynamics.
Why should one study butterflies and their flight? Researcher Per Henningsson, from Lund University in Sweden, who studied the butterflies' aerodynamics, explains in a release that the shape and flexibility of butterfly wings could inspire improved performance and flight technology in small drones.
