An electric fence is an option but it would need to be a fence, not a couple of current carrying wires. We have current carrying wires here in an attempt to prevent the sheep and donkeys wandering. Ive seen a fox step through them. The other point is a fence that will cover the area that your chickens range is likely to cost a considerable amount of money and require constant maintenance. We have thousands of metres of the stuff here and it's a complete pain in the ****.
There are foxes here and usually they don't hunt until dusk which is also the time the free range chickens here return to their coops or go up the trees. What does seem to keep the foxes away are the dogs; we have two. It's not just the dogs here, everyone on the mountain has dogs loose and this makes it difficult for a fox to travel from place to place undetected.
Reluctantly I think your best option is to kill the fox.
There are foxes here and usually they don't hunt until dusk which is also the time the free range chickens here return to their coops or go up the trees. What does seem to keep the foxes away are the dogs; we have two. It's not just the dogs here, everyone on the mountain has dogs loose and this makes it difficult for a fox to travel from place to place undetected.
Reluctantly I think your best option is to kill the fox.