It’s routine practice for government officials to kill animals deemed invasive or destructive. For the most part, Americans accept this or look the other way — especially if the "pests” are insects, rodents or garden-munching deer. That’s changed now that the Fish and Wildlife Service plans to shoot thousands of owls in California, Oregon and Washington.

The species on the hit list is the barred owl — a creature whose adaptability has enabled it to spread into new areas. This expansion is driving the increasingly rare spotted owl to extinction.

This isn’t just natural selection in action. All over the world, human activity has changed landscapes so fast that the diversity of plants and animals is collapsing — with a few hardy species taking over. In an attempt to stop this, authorities around the world are protecting coral reefs by killing starfish, protecting salmon by killing sea lions and protecting red squirrels by killing gray ones.