(AP)—Federal wildlife officials plan to dispatch armed bird specialists into forests of the Pacific Northwest starting this fall to shoot one species of owl to protect another that is threatened with extinction.

The U.S. Fish and Wildlife Service on Tuesday released a final environmental review of an experiment to see if killing barred owls will allow northern spotted owls to reclaim territory they've been driven out of over the past half-century.

The agency has been evaluating the idea since 2009, gathering public comment and consulting ethicists, focus groups and scientific studies. It will issue a final decision on the plan in a month.

"If we don't manage barred owls, the probability of recovering the spotted owl goes down significantly," said Paul Henson, Oregon state supervisor for the U.S. Fish and Wildlife Department.

The agency's preferred course of action calls for killing 3,603 barred owls in four study areas in Oregon, Washington and Northern California over the next four years.

Neither the timber industry nor the Audubon Society was pleased with it.

"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," said Tom Partin, president of the American Forest Resource Council, a timber industry group.

Bob Sallinger, conservation director for the Audubon Society of Portland, said saving the spotted owl is of paramount importance, but the focus must remain on protecting habitat.

"To move forward with killing barred owls without addressing the fundamental cause of spotted owl declines, from our perspective, is not acceptable," he said.

Henson said the Northwest Forest Plan, which cut logging by 90 percent on national forests in the 1990s, has done a good job of providing habitat for the spotted owl. But the owls' numbers have continued to slide.

Henson said unless barred owls are brought under control, the spotted owl in coming decades might disappear from Washington's northern Cascade Range and Oregon's Coast Range, where the barred owl incursion has been greatest.

The idea of killing one type of owl to protect another underscores a fragile balance of nature that biologists have struggled with for years.

Between 2000 and 2006, wildlife officials captured and removed more than 40 golden eagles from the Channel Islands off Southern California to protect the island fox. They also hired a company to kill 5,000 feral pigs on Santa Cruz in a controversial program to restore the island's ecosystem.

In Oregon, officials have used lethal injections to kill selected California sea lions that feast on protected salmon in the Columbia River. And in Yosemite National Park, saving bighorn sheep has meant hunting protected mountain lions.

The northern spotted owl is an icon of bitter disputes between the timber industry and environmentalists over the use of Northwest forests. Because of its dwindling numbers, the little bird was listed as a threatened species in 1990, which resulted in logging cutbacks and lawsuits.

Barred owls are bigger, more aggressive and less picky about food. They started working their way across the Great Plains in the early 1900s, and by 1959 were in British Columbia. Barred owls now cover the spotted owl's range, in some places outnumbering them as much as 5-to-1.

The Fish and Wildlife Service's proposal calls for a combination of killing and capturing barred owls. But capturing owls is far more expensive and difficult. And the agency has found only five zoos or other facilities willing to take a barred owl if it's captured, said Robin Bown, the wildlife biologist in charge of the evaluation.

Henson said the service has yet to work out details of how barred owls will be killed, whether by government hunters from the U.S. Agriculture Department's Wildlife Services, or by contract hunters.

The favored method involves luring the birds with a recording of a barred owl call, then shooting them with a shotgun when they fly in to drive out the intruders.

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