GRANTS PASS, Ore. (AP) – Federal biologists have agreed to consider changing Endangered Species Act protections for the northern spotted owl from threatened to endangered.

The U.S. Fish and Wildlife Service will announce Wednesday there is enough new scientific information in a conservation group’s petition to warrant a hard look, which will take about two years. A notice will be published Friday in the Federal Register.

After the northern spotted owl was listed as a threatened species in 1990, it became a symbol for Endangered Species Act protections that harm local economies. Conservation groups won court-ordered logging cutbacks to protect owl habitat that put many Northwest timber towns into an economic tailspin from which they have yet to fully recover. Political efforts to ramp up logging in the ensuing years have largely failed.

Paul Henson, supervisor for Fish and Wildlife in Oregon, says a lot has changed since the original listing. Back in 1990, the biggest threat to the owl was cutting down the old growth forests where the owls live. Now it is the barred owl, an aggressive cousin from the East Coast that migrated across the Great Plains and invaded spotted owl territory. Those two areas will be the focus of the review, he said.

“The bad news is that the spotted owl population has continued to decline,” despite logging cutbacks of about 90 percent on federal lands in Washington, Oregon and Northern California, Henson said. “The good news is we know why it is declining,” and have begun taking steps to deal with the barred owl.

Spotted owl numbers have continued to decline, and the species is estimated to number less than 4,000. The bird’s status was last reviewed in 2011, when Fish and Wildlife felt it still warranted protection as a threatened species. The agency typically reviews the status of protected species every five years. This review was brought on by a petition from the conservation group Environmental Protection Information Center in Arcata, California. The review is set to be finished by September, 2017.

In addition to protecting and promoting old growth forest habitat for the owl, the agency is conducting an experiment to see if killing barred owls in selected areas in the three states will allow spotted owls to move back into their old habitat. Some barred owls have been killed in Northern California on private timberland and the reservation of the Hoopa Valley Tribe. After surveys for spotted owls and barred owls are finished, killing barred owls is to begin this fall in Oregon and Washington. The experiment should be finished in three years.

An endangered listing would change little on the ground, Henson said. Habitat protections and prohibitions against killing owls would remain the same. No more money would be available for restoration. One difference is that Fish and Wildlife would lose the use of the 4(d) rule, which gives the agency some flexibility to relax protections on threatened species if protections are harmful to people. There are currently no 4(d) rule actions in place on the spotted owl.