Sounds like quail to me. They are beautiful birds and they tend to roost together in a circle on the ground and when disturbed, they flush and will scare hades out of you.
We use to have them around my house but the ground cover gradually disappeared as more houses were built. They are no longer around my house.
I would rule out pheasant and grouse. Both of those are much larger than a quail. Count yourself lucky if you have quail. If indeed that is what they are, you will have them as long as there is ground cover and the foxes do not get them. They can fly pretty fast but generally do not fly far. They are a favorite of southern hunters.
Paul E. Smith