Not to be confused with the butterfly family Birdwing.
The skeleton of a bird wing. Places of attachment of various groups of flight feathers are indicated.The mute swan with outstretched wingsWing of the white-tailed eagle
^Vargas, A. O.; Fallon, J. F. (2005). "The Digits of the Wing of Birds Are 1, 2, and 3. A Review". Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 304 (3) (Journal of Experimental Zoology Part B: Molecular and Developmental Evolution ed.): 206–219. doi:10.1002/jez.b.21051. PMID15880771.