Leucistic Female Mallard

"Leucism is a condition in which there is partial loss of pigmentation in an animal -- which causes white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes." from Wikipedia

Spotted this unusual looking duck in the middle of several dozen Mallards.  I initially thought it was a cross between a domestic and non-domestic Mallard, but then remembered a discussion about albinism and leucism from my birding class.