I live in the Pacific Northwest, and our falls/winters/springs can be pretty wet. I have read numerous threads about what people think are the best materials for their chicken runs, OR, their duck runs, but what if I have a duck that shares a run with chickens? I have 8 chickens, and one Pekin duck. The run is 10' x 40', plus they free range during the day. Right now, I am using straw, and we have clay soil and rock underneath. Needless to say, it doesn't drain, and the straw gets mucky. And as I'm sure all who own ducks are familiar with, my duck likes to root around in the muck, making it muckier. I was thinking pea gravel, but thought that might be too rough on her feet (duck's, not chickens'). Then I thought sand, but was worried she (my duck) would keep rooting through it, possibly ingesting some. ( not to mention, make a much more horrible mess in their water than she already does.) I also thought pine shavings, but I'm thinking that would take many, many layers to be effecient, and in a 10' x 40' run, not sure that would be very economical. Any suggestions??? Thanks!