F.D. Flam: If killing 1 species might save another, should we do it?

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.

But the case of the spotted owl is unusual because, to the untrained eye, it looks almost the same as a barred owl. The two species are so closely related, they sometimes mate and produce hybrid offspring. That’s forced a reconsideration of big ethical questions: Is it moral to kill in the name of ecological balance and diversity? And, if it can be, how do we decide which species are acceptable to target?

Field experiments show shooting barred owls can stave off the decline of the spotted owl, but there’s no end point. The current plan under the Fish and Wildlife Service would go on for 30 years and kill up to half a million owls. But it’s understood the shooting would have to go on forever to save the spotted owl.

In the 1980s and 1990s, environmentalists used the spotted owl’s status under the Endangered Species Act to argue a fraction of the old-growth forest in the Pacific Northwest should be protected from logging. They succeeded, but the spotted owls continued to decline — losing 80% of their numbers in the past 30 years.

Scientists and bird watchers witnessed the bigger, more aggressive barred owl move in and outcompete spotted owls for food and nesting sites. And it’s not just the spotted owl that’s at risk — the barred owl’s proliferation might be hurting the local screech owl and pygmy owl populations. Some scientists worry human activity has depleted the spotted owl populations and accelerated the barred owl’s expansion.

A recent New York Times op-ed piece also argues against the killing, citing “genomic evidence that the barred owl has in fact resided in the Pacific Northwest for thousands of years.” But that was at odds with what all the scientists told me, and the paper cited didn’t appear to make that case, so I called one of the authors, biodiversity scientist John Dumbacher.

He said the Times piece misrepresents his work, which, he said, shows there’s more genetic variation among barred owl populations than thought. “The data are clear at this point: The barred owl is an existential threat to the spotted owl,” he said. The spotted owl is “disappearing at a rate that’s blowing away the scientists.” If humans hadn’t drastically depleted their numbers by destroying much of the old-growth forest they depend on to survive, maybe they’d have stood up better to the barred owls.

“The science is all very clear about what’s going on,” Dumbacher said, “but the science doesn’t tell you what to do about it.”

For that, we need ethical arguments. The public should have a say, as well.

There might be no good path forward. What might be more important is proceeding wisely — having an end goal, learning from mistakes and doing what we can to avoid coming to this juncture in the future.