The key is the term "free range." Nilgai, Axis and Aoudad have essentially become new "indigenous" species across much of south central and southern Texas, extending into New Mexico. These are great, challenging hunts - particularly Nilgai and Aoudad. Like the Limpopo, the same animals can be potted behind a high fence. It tends to be not quite the same experience.
A Nilgai on the free range coastal plains of southern Texas are one of the wariest and most challenging animals I have ever hunted anywhere. An Aoudad taken from the mountains around Alpine or Marathon can be as challenging as a desert bighorn.
The same animal on a thousand acres behind a fence outside Kerrville in the Hill Country is a very different experience.