The U.S. Fish and Wildlife Service on Thursday proposed saving the endangered northern spotted owl by shooting more than 400,000 barred owls in Oregon and Washington over a 30-year period.

More than 20,000 barred owls would be shot the first year, according to fish and wildlife’s plan. Thereafter, 13,400 to 17,400 would be killed each year for 30 years.

Without removing barred owls, the spotted owl may disappear from the Northwest, according to a draft environmental impact statement on the plan.

“Therefore, the management strategy needs to provide for rapid implementation and result in swift reduction in barred owl numbers,” the statement reads.

The northern spotted owl was listed as an endangered species in 1990. To preserve owl habitat, timber harvests were reduced. The barred owl emerged more than a decade ago as another threat.

Barred owls eat more species than spotted owls. With more food available wherever they are, barred owls have greater population densities and crowd out spotted owls.

Barred owls are categorized as an “alien species” because they migrated westward from the Eastern U.S. and were not detected in the Northwest until 1959.

While great lengths have been taken to preserve spotted owls, barred owls are seen as an ecological menace because their wide-ranging appetites could lead to “cascading effects” on food webs, according to the fish and wildlife service.

“This could affect not only spotted owls, but entire ecosystems,” the draft environmental impact statement states. The draft also states the U.S. Fish and Wildlife Service does not have sufficient information to verify whether barred owls are effecting specific species.

The service has experimented with shooting barred owls and reports success in at least stabilizing the population of spotted owls in a particular area. The agency now proposes killing barred owls on a bigger scale.

Barred owls would be shot in forests on the Olympic Peninsula, in the Cascade Range, the Oregon Coast range and Northern California, where barred owls are seen as a coming threat to the California spotted owl.

Recordings of the barred owls’ distinctive “who-cooks-for-you” call would be played to lure barred owls within shotgun range.

One to three shots should kill both the male and female in mating pairs, according to the fish and wildlife service.

The agency looked at managing forests to give spotted owls an advantage. “Unfortunately, barred owls can occupy all forest conditions used by spotted owls and displace spotted owls under all conditions,” the draft impact statement states.

Barred owls and spotted owls occasionally mate. The hybrids will be shot, too, as a threat to the spotted owl’s “genetic identity,” according to the draft statement.

The fish and wildlife service last year announced it would develop a plan to kill barred owls and asked for public comments. Most environmental organizations and timber companies embraced the idea.

Some individuals commented that barred owls are beautiful and shouldn’t be slaughtered, and that the agency shouldn’t interfere.

“Leave both species alone and let them work it out,” a woman commented.