Found inside a little hole in the snow, in shade. Probably blown into that spot. One more feather seen 2 m or so from these two, about the size of the top one. Feathers were grey, shading to white. There is a bridge about 30 m away. No evidence of blood here or around the bridge. It's still cold here (-18 C this morning), so I can't think of any bird in this area besides the Pigeon.