The survival of one owl species depends on the demise of another.
That's what the U.S. Fish and Wildlife Service claims in its proposal to allow the organization to shoot hundreds of thousands of barred owls in West Coast forests over the next thirty years. The agency says the barred owl, which is not native to the region, is displacing the spotted owl, a close genetic relative.
Without action on the barred owls, service biologists say the spotted owl could disappear from parts of Washington and Oregon within a few years and eventually become extinct.
The proposal is the latest in a series of efforts to save the spotted owl, whose decline became a rallying point for environmentalists who opposed logging in the Pacific Northwest in the 1980s.
Human influence - as European settlers spread west - likely caused the barred owl to colonize the Pacific Northwest. Now the proposal is raising questions about how far people should go to save a species and the costs of righting a historic ecological wrong.
"It's not the barred owls' fault. It's our fault for bringing them here. It's not the spotted owls' fault, either," said Robin Brown, a Fish and Wildlife Service biologist who heads the agency's barred owl strategy. "The future of this species is extinction if we don't control barred owls. The writing is on the wall."
The agency's proposal, which calls for the "lethal removal" of a total of more than 470,000 barred owls - killed with shotguns - remains in draft form and open for public comment through Jan. 16.
Spotted versus excluded
An undiscriminating eye may have difficulty telling spotted and barred owls apart. Both have pale faces and brown and white spotted coats. They belong to the same sex. Before the 20th century, a major differentiator was where they lived: the barred owl in the eastern US and the spotted owl in the woodlands of the western US.
But the barred owl is slightly larger, reproduces faster, more aggressive and less picky about where it makes its home and what it eats.
Spotted owl populations have declined by about 75% over the past two decades and continue to decline by about 5% each year, largely due to barred owls, according to an environmental impact statement describing the USFWS proposal. According to the proposal, more than 100,000 barred owls live in the West Coast forests.
"They come to these areas. They reach high densities. They eat basically anything and compete with spotted owls for food," said David Wiens, a supervisory research wildlife biologist for the US Geological Survey.
The USFWS' proposed management plan calls for culling barred owls in about one-third of spotted owl range in Washington, Oregon and California over three decades. The plan would remove the barred owl from 1%-2% of its current range.
Crews of trained shooters sent out an owl call, attracting people nearby. Then, equipped with spotlights and shotguns, they would kill the birds.
The USFWS funded an experimental study - led by Wiens - to see how well the strategy worked over five years in five forest areas in the Pacific Northwest. The results, published in 2021, showed that approximately 2,485 barred owls were killed and that spotted owls had a 10% better survival rate in areas where they were removed.
The removal stabilized the spotted owl population, but did not substantially increase it. Brown said the agency thinks it will take longer than five years for the spotted owl population to turn around because the birds don't reproduce very quickly.
Given the dominance of the barred owls, it is likely that their populations will recover over time. Therefore, the USFWS would likely need to "manage the species on an ongoing basis," Brown added.
Kessina Lee, the USFWS state supervisor in Oregon, said wildlife biologists consulted an ethicist about killing the animals. Lethal removal is justified when the alternative is the extinction of a species, Lee said.
"Sometimes it is necessary for people to intervene to correct an unnatural situation," she said.
Some animal rights organizations disagree.
Friends of Animals, a Connecticut-based nonprofit animal advocacy group, unsuccessfully challenged the USFWS' permit to conduct the 2021 study.
"We don't think it's ethical to go out and call for barred owls and shoot them with a shotgun, because they are currently doing better in the existing environment and outcompeting other species," said Jennifer Best, who leads to the organization's natural law program. .
Best said, species are constantly adapting to different pressures and moving to new environments due to threats such as climate change.
"How to approach that needs to be addressed and considered. Killing the flowering species is not a good solution," she said.
Decades of work to protect spotted owls
Barred owls came to the Pacific Northwest forests at a time of unrest.
In the late 1980s and 1990s, environmentalists and loggers fought over timber harvests in the old-growth forests that remained - a conflict known as the Timber Wars. The spotted owl, which prefers to live in the huge old trees that are dwindling, was at the center of the debate.
The battle ultimately led to protections for the bird and its habitat, as well as a plan to preserve old-growth forests on federal lands. In 1990, the owl became an endangered species under the Endangered Species Act.
Those measures helped - until the barred owls took over.
Biologists think climate changes in Canada or human-induced changes in the Great Plains - such as an increase in forest habitat as humans wiped out the beavers and buffalo that stunted tree growth - may have enabled the spread of barred owls.
"Over a period of about 100 years, they slowly moved through that area. Once they hit the west coast and the forest there, they really started to explode," Wiens said.
But Best views the barred owl as a scapegoat and thinks killing it is a distraction from taking bolder steps to preserve spotted owl habitat.
"I think protecting old-growth forests in areas where spotted owls live and can live is the most important thing - and working to restore habitat that has been destroyed. It is not an easy or quick solution, but it is the potential solution for the long term," said Best.
After the public comment period for the USFWS proposal ends, a final proposal is expected in the spring or summer.
This article was originally published on NBCNews.com