Hi, Tracy, I just heard from Bev. The chicks have frounce/Trichimonas. Gordon is treating them, and there is a good chance of recovery. And I think you are right about winter here: we used to get really cold winters, -30 below for days at a time, but with climate change we no longer get the really cold weather. Also, as an aside, this is why we now have a problem here in Alberta with the mountain pine beetle. So, the upshot of all this is that as we no longer get really cold winters, and we have not dealt with this before, we don't know where this will lead us. Of course, the weather may not be the problem, or the only problem, but I think you are right, considering that we have had dirty nest boxes in the past, without problems.