Details will be mailed to swan supporters later this fall. We're excited about all the helpful suggestions and creative ideas for improvement of our programs, newsletter content, and membership services. Watch for developments in future issues of Bridges . Cranes, like raptors are soaring birds, they flap their wings only to gain enough altitude to take advantage of rising columns of warm air that propel them skyward. On 6 foot wings they prospect the air for thermals then circle to staggering heights extracting every meter before effortlessly gliding to the next area of liberating lift.
Migration is a succession of lofty circles with a southward drift.
So refined is their sense of the air that they can feel the subtle wake created by the bird flying ahead of them. They exploit that lift and ride so closely that their formation forms a chevron. Our aircraft also produces a wake and in slow flight it is large enough to carry several birds. By following very closely they forgo the need for thermals and surf the vortices that roll off our wingtips . If the air is not smooth and we begin to bounce the birds can no longer stay in tight formation and they must resort to flap flying.