Good perimeter fence is a big help, at least for the typical free ranging during the day. IMO one of the biggest reasons for having a good perimeter fence is to prevent dogs allowed to roam free from getting in the yard. If a dog can get in your yard easily or relatively easily.. you can pretty much be guaranteed to eventually find a dog or dogs inside your yard, killing MANY chickens at once.
Good perimeter fences do not stop hawks that will go after chickens though.. generally fully grown standards are safe, except for the occasional hawk brave enough to go after one. Small babies or juveniles are definitely targets for most hawks. During the season when they are here(fall/winter) I cannot have any baby chicks loose.. the hawks are instantly upon them, sometimes even swooping while I am outside just 10 feet away.
Good perimeter fences do not stop hawks that will go after chickens though.. generally fully grown standards are safe, except for the occasional hawk brave enough to go after one. Small babies or juveniles are definitely targets for most hawks. During the season when they are here(fall/winter) I cannot have any baby chicks loose.. the hawks are instantly upon them, sometimes even swooping while I am outside just 10 feet away.