Unconventional lift-generating mechanisms in free-flying butterflies

Nature. 2002 Dec 12;420(6916):660-4. doi: 10.1038/nature01223.


Flying insects generate forces that are too large to be accounted for by conventional steady-state aerodynamics. To investigate these mechanisms of force generation, we trained red admiral butterflies, Vanessa atalanta, to fly freely to and from artificial flowers in a wind tunnel, and used high-resolution, smoke-wire flow visualizations to obtain qualitative, high-speed digital images of the air flow around their wings. The images show that free-flying butterflies use a variety of unconventional aerodynamic mechanisms to generate force: wake capture, two different types of leading-edge vortex, active and inactive upstrokes, in addition to the use of rotational mechanisms and the Weis-Fogh 'clap-and-fling' mechanism. Free-flying butterflies often used different aerodynamic mechanisms in successive strokes. There seems to be no one 'key' to insect flight, instead insects rely on a wide array of aerodynamic mechanisms to take off, manoeuvre, maintain steady flight, and for landing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Movements*
  • Animals
  • Butterflies / physiology*
  • Flight, Animal / physiology*
  • Flowers
  • Smoke
  • Wings, Animal / physiology*


  • Smoke