You are what you eat
Cedar Waxwing -- Central Park--November 18, 2011
(Cedar Waxwings...The pigment in the berries they eat contributes to their tail wing tip color,
colors range from yellow to orange to close to red)
Probable Dietary Basis of a Color Variant of the Cedar Waxwing. Journal of Field Ornithology. vol 60, no 3. pp. 361–368.
Hudon J & Brush AH. (1989).
Photo, headline and info by MURRAY HEAD