I have observed that upon stocking of sub adult and adult fish, they seem to "go exploring" the perimeter of their new environment. Most of the juveniles don't make it very long.
Livestock do the same thing.
I recently talked to a deer rancher who told me when he changes deer from one pen to the other, they are initially confused and explore the limits of the pen or the perimeter. However, placing a downed tree in the pen initially attracted them to the cover. These deer had never known free range but were pen raised to improve genetics for breeding purposes. The pen fences are lined with black plastic mats to keep them calm. I have always that all animals are attracted to structure or just something different. Even humans.
I believe that introducing stockers into a complex habitat of cover should let them get their bearings and decrease initial predation. However, sooner or later, like all children, they gotta come out and face the real world.
