The eagle then glides for several miles to the next thermal without flapping its wings at all. Compare that to a hummingbird which beats its wings 75 times per second when in flight. Air currents in a thermal can be very strong and turbulent. Ask any pilot, and you're sure to hear stories about planes hitting thermals unexpectedly. Pilots watch for the cumulus clouds which often form at the top of a thermal, but sometimes there is no visual clue at all.
Eagles do get a free ride when riding thermals, and can migrate great distances with ease.
But it does require energy for an eagle to travel. List as many examples as you can. Please include the name of your school and your location so we can credit you properly for your answers. The Next Bald Eagle Migration Update Will be Posted on May 5, 1997.