We have a section of our yard fenced. We have a 6 foot privacy fence on two sides, the house on one and 3 foot poultry wire on the other. We've only had this set up for about a week, but they haven't tried to get out yet.
I wonder if it is something like goats in that a lot of it depends on what is on the other side of the fence?
Their run area is about 300 sq ft with lots of stuff...a pile of dirt, a wagon and a baby slide they alternately hide under or perch on, an old garden filled w/ pumice, lots of grass and weeds, a bush and some kind of a daisy they seem to like to sit in.
On the other side of the fence is just mowed grass. Not very interesting.
It is no good for predators, but then we only let them out when we are home and going in and out.
I was a little concerned about the leghorn because I've heard they are flighty. She is the hardest to catch, but she likes her buddies and they are a little more sedentary (a Rhode Island Red, austrolorp, and a red sex link).