Great sites! Found a gorgeous Buff Orpington:
I love your coop - I have been considering the problem of . . . er, coop poop, and a movable coop sounds like a great solution. Much better than removable floors, etc. What are the dimensions and capacity of your coop?
Each chicken needs 4 sqft of solid-covered area and 10 sqft of uncovered or open run for chickens that stay in it all the time. So this coop, being 4x6 feet, is just slightly too small for two chickens. It should be 4x7 feet...2x4 feet of covered area and 4x5 feet of run. But my chickens are free-range during the day...they run around in the backyard free.
Each chicken needs 8" of roost space...that's the bar that goes across the back of ours...
You also need some sort of nest box for every four hens. I don't think you need more than 1 rooster for every 25 chickens and you don't need a rooster at all unless you want fertile eggs.
We made our coop the same dimensions as our square foot garden beds. We have it situated right on top of an unused bed. The chickens can eat and poop in there and in the process, fertilize that particular bed!
Here's a whole bunch of tractors!
http://home.attbi.com/~kkskinner/tractors.html