I decided to sweep my bottom board this afternoon. The hanger I was using was a little too bent to go all the way back, but I got in about 8-9 inches. The end result is pictured below. My question for you more experienced beeks is: does this look like fairly normal winter attrition?
There's still an active buzz coming from inside the hive. I've given the hive a good whiff from both in front of the entrance, and the top. There is no smell of rotting, and the dead bees look quite dry. While clearing them away from the hive entrance (with my boot) I crushed some, and they obviously had a decent amount of fecal material in them (yellow/tan stains on the snow).