How Do Butterflies Fly?
The rounded profile
of a bird’s wing creates an airfoil, which generates lift and allows
the bird to fly. But butterfly wings are flat. How do butterflies fly?
An insect's wings are very different. Each wing is all one piece, made of chiton, the same
substance that makes its exoskeleton. The wings do not have any joints or muscles.
Butterflies look different from many other flying animals, compared to birds and bats.
They have a very extreme wing shape — very large, short but very broad wings
compared to their little body and that is a bit of a puzzle. So how do they move?
The lilting, fluttering flight of a butterfly evokes whimsy rather than efficiency or purpose,
but a new study reveals the mechanics of the insect’s less than linear flight pattern and
suggests it may help them evade predators.
Butterflies evolved an effective way of cupping and clapping their wings to generate thrust.
Butterflies evolved an effective way of cupping and clapping their wings to generate thrust.
The wings are behaving in quite an interesting way, the leading and the trailing edge are
meeting before the central part, forming this pocket shape. When the wings go up during
the upstroke, and they clap together at the end of the upstroke, they were not just two flat
surfaces. Instead, they were bending, and due to their flexibility and they were forming a
sort of pocket shape.
That sort of behavior is going to improve the clap because it forms an air pocket between
the wings which, when the wings collapse, that make the jet even stronger and more efficient.
Because the wings are so big, they make it easier for the insect to maneuver. A butterfly’s
huge wings are like having a massive rudder on the back of a ship – the bigger the rudder,
the faster the ship can turn.
Butterflies also use their wings to make an erratic fluttering pattern, which is unique to
butterflies and very hard for predators, especially birds, to predict which way they will fly.
Rather than flapping their wings up and down like birds, butterflies contract their bodies
making a slanted figure eight pattern with their wings. As the butterfly’s body contracts,
the motion pushes air under their wings, effectively propelling it through the air.
Butterflies and Moths of North America
WisconsinButterflies.org
Southern Wisconsin Butterfly Assn (NABA)
The Butterfly Site