I dont know the sort of area you want to protect but I can tell you what we have done. The chickens free range through our cattle yards and a grassy area where their houses are. I have electric poultry netting -8 rolls- run off the mains round all the open sides. This has worked really well,never had any trouble but its close to the house and people are about all day.
Down at the lake- about 100yards from the house- where our ducks live a semi-wild life, again poultry netting - 10 rolls- plus and extra 18inches of electric fence wire added to the top and still foxes get in. Ive never seen them get in but have seen them go out lots of times and they clear the 5-6ft of electrified wire no sweat, just like a race horse
If i were starting again I would have the whole lot enclosed with the highest wire netting fence possible with a good 2ft spread out over the ground on the outside to stop them digging in and one strand of electric wire about 6inches off the ground about a foot out from the fence.
What about houses and enclosed safe runs for each breeding group. Much safer for them and a much more cost effective option.