An economist in New Zealand named Gareth Morgan has made the logical and quite correct case that his island nation should eliminate its cats in order to protect its endangered birds. He means “elimination” in the most humane way possible: Existing pets should be spayed and neutered and allowed to live out their lives, but no new cats should be allowed to be born or imported. He is not advocating that people poison feral cats, as a former researcher at the Smithsonian National Zoo was convicted of doing a few years ago. Nor does he say people should shoot them, as particularly avid birdwatchers have done. That would be really wrong.