Discussion: Flight Plan

Monarch Butterflies

Discussion: Flight Plan
(Lesson | Demonstration | Discussion)

Flight Plan A is the flight of an eagle. Eagles and many other hawks with large wings circle on thermals to rise as high as they can get. This is also how cranes usually migrate (when they're not following an ultralight!) When the thermal "tops out" they set their wings and move forward, dropping slowly but steadily since they're not flapping. When they find another thermal they spiral upwards on it again. Sometimes eagles, hawks, and cranes flying on thermals can move several miles without flapping once.
Flight Plans

Flight Plan B is a hummingbird's. These birds are so tiny, with relatively small wings, that they must flap every moment to stay in the air. Their flight is direct, but they must stop and feed many times along the way, dropping down when they spot a red flower or hummingbird feeder.
Flight Plan C is a monarch butterfly's. Their bodies are so light that even very tiny eddies and currents of air can push them around, so their flight plan can show a lot of random movements. (A monarch butterfly's flight can also follow Flight Plan A. Monarchs often ride the same strong thermals that eagles and hawks do. And it must be said that we don't know how monarchs travel when they fly in high altitude winds where they cannot be observed.)
Flight Plan D is a crane following an ultralight. Pilots can't feel thermals the way birds can, so they make a bee-line towards their destination with the crane or cranes close behind.