Unusual Grackle

Saw an unusual grackle at our bird bath today. Some of its tail feathers were completely white. I thought it was some rare bird, but after doing an internet search, I believe it is a partially leucistic grackle.  

Bird Leucism is a genetic mutation that results in a total or partial reduction of color in a bird’s plumage. The reduction of color in the bird’s plumage is due to an inadequate deposition or fixation of pigments only in the bird’s feathers. Other parts of the bird’s body have normal coloration.

Common Grackle (partial leucism)