In an open field near a lake in northern Virginia today I spotted flocks of starlings, red-winged blackbirds and grackles all hanging out together. Near the top of the tree I also saw a silhouette of something clearly different from the assembled masses, so I took a shot of it. I've uploaded both the (cropped) original and a heavily-processed version. Even after messing with the levels and bumping up the saturation, I can't make out much except for a white-edged tail. There were some dark-eyed juncos in the area, but this bird was solitary, and it was about 40 feet up in the tree. Is it a junco? Or maybe a mockingbird?