The final plan, developed by a group of federal biologists and outside scientists, proposes spending $489 million over 30 years to return the threatened owl species to a stable, well-distributed population in Washington, Oregon and California.

But the plan will be reviewed after 10 years, because there are so many uncertainties about future risks. Paul Phifer of the U.S. Fish and Wildlife Service, who led the recovery team that developed the draft plan, said it’s not clear whether declining owl numbers across the region can be reversed during that time period.

“The best we can say with confidence is that in 10 years we will probably be having the same conversation,” he said.

The plan calls for protecting 6.4 million acres west of the Cascades,  including “older, complex forests” that are not protected under the Northwest Forest plan; controlling fire and insects that have destroyed large tracts owl habitat in drier forests east of the Cascades; and carrying out “large-scale control experiments” to reduce populations of barred owls, which have invaded Northwest forests in large numbers and aggressively compete with spotted owls for habitat and prey.

Federal agencies dropped a proposal in the draft plan that would have given local Forest Service managers the option of protecting mapped owl habitat or devising their own systems of shifting owl reserves.

“We now have a more landscape approach on the east side and defined reserves on the west side,” said Ren Lohoefener, regional director of the Fish and Wildlife Service for the Pacific Region.

The final plan also takes a more measured approach to the control of barred owls.  The original draft recovery plan was rewritten in the fall of 2006 at the direction of an oversight committee of Bush administration appointees, who ordered the team to put more emphasis on the threat posed by the barred owl. The rewritten draft called for luring barred owls to 18 sites across the region with decoys, then shooting them with shotguns.

Phifer said that plan had been dropped for now. Instead, he said, federal agencies will wait for an upcoming study of the effectiveness of different methods of controlling barred owls. “Lethal control will probably be tried in some areas,” he added.

The northern spotted owl was listed as a threatened species throughout its range in 1990, under the George H.W. Bush administration, primarily due to loss of its habitat to logging. No plan for recovering the owl was ever adopted; instead, the Clinton administration adopted the Northwest Forest Plan as a blueprint for protecting and recovering a range of threatened species, including owls, marbled murrelets and salmon.

Lohoefener stressed that the recovery plan provides guidance only and is not a regulatory document.

“Unfortunately, the northern spotted owl has not recovered since its listing,” he said.  “Today, we believe the most pressing threat is competition from barred owls.”  But habitat loss remains a factor, he said, and the risk of stand-replacing wildfires and climate change create new uncertainties about the owl’s longterm viability.