Flap or Glide?
A biologist named Dr. David Gibo studies monarch butterfly flight. In one experiment, he wanted to find out how much energy monarchs use during different types of flight. He compared the energy a monarch burns during flapping flight and soaring/gliding flight.
A Full Tank of Fuel
Dr. Gibo's monarchs started with 140 mg of stored fat. He measured how long the monarch could fly with this amount of fuel.
Flight Study Results
A monarch with 140 mg of fat could fly for: |
| Type of Flight |
Time Can Fly |
| Flapping
Flight |
44
hours |
Soaring/Gliding Flight |
1,060 hours |
Flapping Flight
Flapping flight is hard work. When a monarch flaps its wings it burns its fuel quickly. The experimental monarchs ran out of fuel after 44 hours of flight.
Soaring/Gliding Flight
When monarchs flew without flapping they could travel 1,060 hours on that single tank of fuel. Soaring/gliding flight is very efficient. Monarchs can travel over 20 times longer on the same amount of fuel.
Wind and Migration
Dr. Gibo's study confirms why the wind is such an important factor during migration. Monarchs can save energy by traveling when the winds are favorable.
"The direction and strength of the winds largely determine the progress of the migration," says monarch biologist Dr. Bill Calvert.
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