Flicker feathers were/are extremely important in the Peyote Ceremony. This seems to have been especially true of the Yellow-Shafted Flicker of Oklahoma, where the Arapahos first began practicing the Ghost Dance. The color yellow is especially associated with the Peyote Ceremony, and thus the Flicker became a key bird.
Flicker feathers are sometimes used today in Pow-wow dress, especially on the head. Flickers also appear in older myths, such as that of Little Star (Dorsey, p. 224), so their importance predates the Peyote Ceremony. Their feathers were used in war implements, to bringswiftness (Kroeber, The Arapaho, p. 432).