But aren’t we evaluating each organism on it’s own? If there is a single escaped/released pet, it’s still effecting the ecosystem (especially if it is a prolific predator) even if it isn’t part of an established population. Also, it could be the progenitor of a future established population, and who is going to go back and retroactively tag these early non-established escaped/releases as established in a few years?
8 Likes