I've wondered what game departments did in the past to have success
with introducing new species like Pheasants and Chukars as I'm sure
many of those first birds were pen raised. I suspect they nuked
the predator populations before releasing and probably had really
good facilities to raise the birds.

Pheasants, Huns and Chuckers are not native to the United States yet there are wild populations of all 3 in states north of here. I think that alone proves that it is possible. Quail require 3 basic things to survive, food, water, and cover. Without any one of those forget it! That being said I believe a little predator control goes a long way. I mean animals that can actually catch quail and destroy their nest. Coons, skunks, snakes, possums, rats, wild hogs,and bobcats, all of these can hurt your quail population. A little over 10 years ago I released over 200 banded birds on a section and a half outside of Big Spring. I had made some changes to the property to help catch and hold water. All the cattle were removed. The birds were released at 4 different times at 6 weeks of age, during a summer we had lots of grasshoppers and no torrential rains. The first batch was released the end of June, the last the end of August. Opening weekend of quail season in November we shot some banded birds along with some wild birds. In December we did the same, we did the same again the last weekend of season ( we only hunted it 3 times) In April I saw a wild male paired up with a banded female. All of the pen raised birds busted and flew with wild birds. I might also add that when 2 of the groups were released I had located wild coveys with a dog and busted them and released the 6 week old birds into the area. I really think that helped. What feed I put out was in the dirt road( No feeders) I know it will work we harvested over 40 banded birds that season, and I know for a fact that at least 1 other survived. Couldn't tell you how many didn't make it but I also know some didn't.