[LongElegantLegs]

Increasing numbers of brown-black squirrels are also being produced as a result of breeding between the two species.

So, it's mutated into an entirely different species? Or do I misunderstand?

[fishtank]

If they can interbreed, they are still the same species.

[Red Badger]

They are not different species.......a Horse and a Donkey are different species which produce hybrid, sterile mules.........