A big cat like that requires an enormous hunting range in the wild. The mountain lion we have here in the US has a range of from 10 to 370 square miles, depending upon prey availbility and gender. Females have a comparitively small territory while males range widely. IIRC, naturalists figure each cat (as they are not sociable critters) needs an averaged minimum of 25 square miles.

One male panther released into the countryside of itty-bitty Scotland would likely be seen by many people, as he will be looking not only for food but also for a mate.

t.