I've done a little research on the term "dominicker" in my ethnographic studies of north Florida people in conjunction with my research on Ida Goodson, who was tri-racial.

The term "dominicker" was used as a pejorative term for bi-racial or tri-racial individuals in the panhandle of Florida in the late nineteenth century. They were said to be the color of a dominicker hen, that is bi-colored.

This definition is from Wikipedia:

The Dominickers were a small biracial or triracial ethnic group that was once centered in the Florida Panhandle county of Holmes, in a corner of the southern part of the county west of the Choctawhatchee River, near the town of Ponce de Leon. The group was classified as one of the "reputed Indian-White-Negro racial isolates of the Eastern United States" by the United States Census Bureau in 1950[1].

This group of individuals had spanish, scottish, African American, and Creek bloodlines (specifically Euchee Indians)as do many of the old timers in the panhandle of Florida. The Holmes Creek community dominickers were said to have migrated to Louisianna where they were called "redbones". They experienced a great deal of discrimination in Florida in spite of the fact that many of them appeared to be mostly white.

Here is some more history of the dominickers of Holmes, Washington, and Walton county in the panhandle: http://www.pineywoodshistory.com/native.html

Chief Story was a dominicker who migrated down the Choctawhatchee to escape racial discrimination in this part of the state. Story Landing, where I have searched for Ivory Bill Woodpeckers is supposed to be the spot where he launched with his group down the "Choc" as the Choctawhatchee is known. His people were Yuchi or euchee Indians of the Creek Nation.