How Butterflies Fly

     How can a butterfly, weighing no more than a feather, fly into the wind and how can they control where they are going given their jerky, erratic flight paths? 
     First of all, no matter if it's a butterfly or a bird, if wind speed exceeds maximum flight speed, then it can't fly. Different species of butterflies fly at different speeds and the range is about 3 miles per hour to a lightning fast 23 miles per hour. Most small butterflies must therefore avoid high winds. 
     Butterflies have big wings and slow wing beats (about 10 per second) compared with about 200 in honey bees and, believe it or not, their wings are more than twice as effective as a bird’s. 
     Recent research indicates they control their jerky, erratic flight by keeping their body perpendicular to the ground and time that with a rotation of their body that is timed with each flap of their wings. A good example of what happens when a butterfly flaps it wings can be visualized by imagining running a spoon through coffee with creamer added. Swirls appear around a low pressure center. Their wings swirl the air above their wings making a low pressure vortex. Thus the vortex sucks the butterfly upward and allows the wings to snap back into position with less resistance. Once the upstroke has been completed, butterflies then preform a quick change of angle, just enough to add even more lift. It's this excessive lift combined with the angle of their body that causes the jerky motion associated with their fight. 
     They have huge wings for their bodies, wings that are way bigger than many other insects of the same weight and their wings are so massive they can fly even with half their wing cut off. Because the wings are so big, it is easy for them to maneuver. Their wings are similar to a ship's rudder; the bigger a ship's rudder, the faster it can turn. 
     Butterflies use their wings to make those erratic fluttering pattern which is unique to butterflies. These erratic movements have a purpose; it makes their movements hard for predators to predict. 
     Monarch butterflies can navigate their way for a distance of some 3000 miles each fall from Canada to Mexico and back in the spring. How do they do it? 
     Birds are known for their long-range migration but not insects, Also, a bird's migration route is a round-trip which they may make many times in their lifetime, but for the Monarch, it is a trip they make only once. 
     A team of scientists at the University of Massachusetts Medical School explored their brains and eye tissues and discovered that it is the ultraviolet band of light that is crucial to their orientation and gived them their sense of direction. The input from UV light detection in the eye and a biological clock in their brain guides them to their destination at the appointed time.