Interestingly, the kinds of birds we have kept cannot be really aptly described as pets since they are chicken though to us, view are pets. We usually keep a small family of about five and we get to know them individually so they double up as pets. Its much harder not to cage wild birds since they will revel in the new found freedom if you happen to release them and they might never come back. Interestingly, I have seen a family in an urban centre who have hundreds of doves as pets yet there isn't a single cage. The birds have been conditioned to be going to his home for feeding on broadcast grains and I doubt they fear him. The most sensible thing to do is to create an area by enclosing it with wire mesh after securing or scouting for the conditions necessary for their natural existence and then release them into the large space. You should provide supplementary food as well as water and occasional cleaning to avoid infections.
