The U.S. Fish and Wildlife Service (FWS) plans to begin culling about 450,000 barred owls from California forests next spring if it approves a new proposal this year.

Federal efforts to protect northern spotted owls and California spotted owls, two native owl species that have been declining in California, have been underway for years. The owls have faced threats from logging, but despite efforts to protect their habitat, both species have declined in population over the past few decades as the barred owl, a non-native raptor larger than other birds, has arrived on the West Coast and outcompeted smaller species, driving them out of their natural habitat.

Authorities began killing barred owls identified in spotted owl habitats 15 years ago to see if the shooting of larger species had triggered an upward trend in the spotted owl population. About 4,500 barred owls have been killed since 2009, the Associated Press reported Wednesday.

If the application is approved, many thousands of barred owls could be shot and killed over the next 30 years after hunters lure them with owl calls. When the barred owls arrive, they will be shot with shotgun shells and buried where they died. If the application is approved, the killing could begin as early as next spring. Less than 1 percent of the barred owl population would be killed each year, according to the AP report.

U.S. wildlife officials say this gruesome tactic is the only way to preserve the spotted owl.

“If we do not take active management actions for barred owls, northern spotted owls will likely become extinct throughout all or most of their range, despite decades of concerted conservation efforts,” Kessina Lee, state supervisor for the FWS Oregon, said in an AP report.

Newsweek contacted the U.S. Fish and Wildlife Service via an online contact form for comment.

Some wildlife organizations, such as the American Bird Conservancy, support the selection process to save other owls. But others see it as a step too far and worry about the safety of the spotted owls if they are misidentified as barred owls and killed.

The FWS plans to designate certain entities to do the gruesome work — not just anyone can kill owls. According to the AP, shooters would have to provide documentation of training or experience in owl identification and firearms skills.

The strategy’s final environmental impact study was released on Wednesday, triggering a 30-day comment period on the proposals before the service makes a final decision.

Meanwhile, this isn’t the first time the U.S. FWS has authorized the killing of one animal to save another. In Michigan, a similar action allowed cowbirds to be killed to save a Kirtland’s warbler. Cowbirds are brood parasites, meaning they lay their eggs in the nest of another, smaller bird, known as the host species. The smaller bird then raises the cowbird’s young as its own. Although the cowbird’s young don’t viciously attack the young of the host species, their larger size often leads to the death of the smaller birds.