Kangaroos have no problem swimming a couple of miles. Not sure about wallabies though. Marsupials are generally good breeders so eventually there will need to

Kangaroos have no problem swimming a couple of miles. Not sure about wallabies though. Marsupials are generally good breeders so eventually there will need to be a cull, but because they aren't hooved herbivores some of the normal destructions doesn't happen, like with goats or pigs.