YELLOW WHITE RUMP
Should have a solid white colored rump area; can have any number of tail feathers that are colored. The "white rumped & white tailed" gene affect the ground (body) coloration of the bird. This is true in this mutation as well as the Yellow White Tail, the gene affects the ground color to the point that it is not the "yellow" color as in the solid colored mutant (Yellow). The wing spots can be enlarged or elongated or barred. Knowing the shading & coloration differences in the primary flight feathers can help identify the mutation. See the "open wing" comparison pictures to help determine the correct mutation.