A wild, breeding population means that there is annual reproduction sufficient to replace annual mortality, absent any human restocking, whether intended or not.
Let me tell you a true story about cougars in Pennsylvania. Years ago, a fisherman called my boss to report that a cougar was following him along a creek and back to his car. My boss responded to the scene and found a cougar waiting in the edge of the woods. He tied a rope around its neck, led it back to his truck, whereupon the cougar climbed in to the back seat.
Was that a wild, breeding cougar? Individual sightings mean nothing; we need PHYSICAL EVIDENCE of a wild, self-sustaining population.
Let me offer a further analogy: I get a call that Cspan is a poacher, based on an eyewitness report. I slap the cuffs on the Cspan, and take him the local magistrate. The judge asks me "Where's the PHYSICAL EVIDENCE to support your claim?" Eyewitness statements are the LEAST dependable form of evidence; any lawyer will tell you that.