Wolf reintroduction involves the reintroduction of a portion of grey wolves in areas where native wolves have been extirpated. More than 30 subspecies of Canis lupus have been recognized, and grey wolves, as colloquially understood, comprise nondomestic/feral subspecies. Reintroduction is only considered where large tracts of suitable wilderness still exist and where certain prey species are abundant enough to support a predetermined wolf population.

Local extinction, also extirpation, is the termination of a species in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions.