OLYMPIA — The northern spotted owl, which won federal protection in the forests of the West 15 years ago, is in serious peril despite logging restrictions that cost thousands of jobs.

One culprit: the barred owl, described yesterday as the "bigger and nastier" cousin that is contributing to the demise of the little spotted owl.

The Washington Forest Practices Board took testimony on the worsening problem and one early strategy: Federal agents plan to shoot some of the barred owls in a California experiment to see if the spotted owl will rebound.

The barred owls migrated to the West from the Great Plains and prey on the food of the smaller birds, push them out of nesting areas, mate with them and even kill them. Their numbers are exploding, displacing spotted owls, which are in a steep decline, experts told the panel.

"They're just bad news," said Steven Courtney, a scientist with Sustainable Ecosystems Institute, a nonprofit group of more than 300 affiliated scientists based in Portland. "We don't have a final scientific prediction of where this will all end up, but it is a major threat at this time."

Despite all the logging cutbacks and other aggressive steps, the spotted owl remains at "significant risk of extinction," he told the board.

The barred owl, loss of habitat due to wildfires and harvesting, and the West Nile virus all are contributing to the owl's steep decline of 30 percent over the past decade in some areas, said Robert Anthony, an Oregon official who works with the Interagency Regional Monitoring Program.

The spotted-owl decline already is as significant as one might have expected in 50 years, he said.

The federal experiment, not yet under way, involves killing some of the barred owls in a small area in the southern Cascades to see if spotted owls reclaim some of their lost territory and grow in numbers. If it works, regulators could authorize shooting thousands of barred owls in Washington, Oregon and California.