Excerpt:
Non-native animals are often a terrible problem for native wildlife. But not always (honey bees come to mind). There's little that can be done about zebra mussels, starlings, Japanese barberry and most invasive aliens. Yet before we exterminate the ones we can truly bully, let's be sure they're really a problem. And let's be sure that utter extermination is really the best goal. Or else, like the mute swan itself, let us hold our peace.