"Adaptations for Flight" . Birds of Stanford . Stanford University . http://www.stanford.edu/group/stanfordbirds/text/essays/Adaptations.html . Retrieved 13 December 2007 .   Based on The Birder's Handbook ( Paul Ehrlich , David Dobkin, and Darryl Wheye. 1988. Simon and Schuster, New York.) ^ a b c d e f g h i j k l