A proposed animal management plan in the Pacific Northwest calls for the killing of one species of owl for the sake of saving another.

On Tuesday the U.S. Fish and Wildlife Service (FWS) made its final review of a proposed experiment in three states to determine whether killing barred owls will aid populations of northern spotted owls, which have faced the threat of extinction after decades of habitat loss, and more recently threats from barred owls. Barred owls are larger and more aggressive than northern spotted owls, which has led to the smaller birds being bested in competition for food and territory.

But it's not just a matter of survival of the fittest with the northern spotted owl on the losing side. Conservationists contend that barred owls were introduced by man into the northern spotted owls' native territory.

"It's possible, but that's the assumption that this is a natural event," Robin Bown, a biologist with FWS, told Seattle news station Q13 Fox. "To do that, you'd have to assume that the barred owl got here on their own."

Barred owls are native to the East Coast and were driven west by human development starting in the 1900s. They are said to have reached the West Coast by the 1970s and their numbers have multiplied since then. In some areas the barred owl outnumbers the northern spotted owl by 5-to-1.

The FWS plan calls for the killing or capture of more than 3,600 barred owls in four study areas in Oregon, Washington and Northern California over the next four years.

The $3 million plan got its legs in 2009 and has been refined and evaluated over the years by gathering comments from the public, evaluating scientific studies and consulting ethicists, the Los Angeles Times reported. The FWS will issue a final decision on the plan within 30 days; if approved, the project would begin in the fall and continue for three or four years.

Some are critical of the project, saying that removing owls is shortsighted in the overall goal of forest protection.

"Shooting a few isolated areas of barred owl isn't going to help us as forest managers, nor is it going to help the forest be protected from wildfires, and catastrophic wildfire is one of the big impediments to spotted owl recovery," Tom Partin, president of the American Forest Resource Council, a timber industry group, told the Associated Press.

But if northern spotted owls begin to repopulate and thrive in areas where the barred owls were removed, the plan will be considered a success by the FWS. But Bown notes that it is uncertain if the experiment will produce the intended results.

"In this case, we're only proposing an experiment. A fairly small-scale experiment to test if this will even work," Bown said to Q13. "Our only other alternative is really to sit back and watch the spotted owl go extinct."