Northern Flicker is a familiar bird throughout the lower 48 states and southern Canada. Within that wide range it occurs in two strikingly different forms, long ago considered separate species: “Red-shafted Flicker” in the west, “Yellow-shafted Flicker” in the east.
The two forms differ most obviously in the color of the large feathers of the wings and tail, either red or yellow, respectively. They also differ in head pattern. In the middle of the continent, however, the forms mix, and it is common to see flickers with intermediate wing and tail color. Anywhere between the eastern edge of the Rocky Mountains and the eastern edge of the Great Plains you should expect to see some flickers with intermediate colors. On closer inspection, these birds also show mixed head patterns, confirming their identity as intergrades.