A variation on the endless mallard duck question: a few weeks ago near the North End, I noticed a small gang of sparrows, one of which was randomly mottled white over about 1/3 of its feathers. I'm reasonably sure this was a natural color variation of the feathers (and not a result of having been splashed in paint). It seemed to be a normally-patterned House Sparrow in the areas that weren't white. Have you ever seen anything like that? I haven't!