I thought this was an interesting concept...3D elec. fencing. This is shown for deer, but seems like something like this would work for other preds as well if spaced appropriately.
http://www.premier1supplies.com/fen...&utm_medium=email&utm_campaign=July-11-Garden
http://www.premier1supplies.com/fen...&utm_medium=email&utm_campaign=July-11-Garden