On Saturday, November 9, 2013 11:55:11 PM UTC-5, son_of_flubber wrote:
The bird loses energy from drag. How does it regain the lost energy to maintain equilibrium?



My guess is that bird gains energy from the upward impetus of the "rotor" produced by the wind shear (not shown in graphics).

Nope.

This may help.

http://www.youtube.com/watch?v=SVN-oF6tPLc

T8