I have the same ledge problem! I've been losing birds right and left. Finally, I figured out the solution. I ran boards as close to the ground as I could, and fenced the top and 4 sides... then sandwiched 2' turkey wire between the bottom boards and some strapping (cheap long boards), making an 'apron' all around the outside edges. I weighted it with big rocks, and am going to put dirt over the edges when I get time... It's been a week, and other than lots and lots of fox poop all over the ground all around the coop, it's great, no foxes have made it inside.... and the roll of 50' wire was only like 13 dollars.