With all the negative experience of introducing new speciesaround the world your pigs probably wouldhave to be eradicated.[]I guess that in the far north many plants often grow very very slowly and a pig can probably ruine large areas for quite some time.

The harassments and problems can perhaps be related to the facts that the pigs dont find enough to eat and are getting desperate. Or that they are first generation escapers and remembers that food comes from humans.
I am only guessing now[&:]