A solar hot wire system works very well.  I had my poultry (turkeys, ducks, chickens) on some acreage in de Luz and had a coyote problem.  They figured out how to dig under the dig skirts (backed up and started digging about 3 feet from the fence and got under the leading edge of the skirt) and killed about 20 birds.  I had a solar hot wire unit but hadn't gotten it installed yet. 
 
I left the bodies they didn't take in the pen, and moved all the birds into a temporary pen, then got the hot wire installed.  They came back, I could see where one started to try to dig and I'm sure the wire hit it because there we only a few dig marks.   I also found where they dug under the perimeter fence and filled that back in after I let them have their one return visit to learn about the wire. 
 
They haven't been back since.  I am living on the property now and have dogs so I'm sure that helps, but there was a good 6 month period between the attack and when I moved out there with no more issues.  Actually they avoid my property completely now, although I hear them all around singing at night.