They have to adapt or die. But I liked the squirrel story that Heero posted about recently. We have a "thing" for squirrels here.
I once owned a grey squirrel. I was on a building site when a terrible storm took place, hurricane force winds and heavy rain. As I left the site I saw something move in the grass. I picked it up to find it was a baby grey squirrel. I saw no sign of Mrs. Squirrel so I took him home and gave him milk by soaking crust until she was able to eat solid food. She came into season December 21 when I let her go in the local park where several other squirrels lived. Me and Mrs. V went out with food at least once a day and a few weeks later she appeared with three young. Though I could approach her, she wouldn't hop on to my shoulder as she'd previously done. She was a treasure and an experience.