Printable Heart Wings Coloring Page
Wing, in zoology, one of the paired structures by means of which certain animals propel themselves in the air. Vertebrate wings are modifications of the forelimbs. In birds the fingers are reduced and the forearm is lengthened. The primary flight feathers on the distal portion of the wing create most of the propelling force in flight, while on the less mobile upper wing the secondaries provide the greater portion of the lift.