In November, the U.S. Fish and Wildlife Service proposed shooting over 400,000 barred owls over the next 30 years in order to save endangered spotted owls. The agency has experimented with shooting barred owls in the past. Now, they are proposing to do it on a much larger scale.
Kessina Lee, supervisor of the U.S. Fish and Wildlife Service office in Oregon, pointed out that the agency has a legal responsibility to protect the endangered spotted owl.
“Rather than choosing to conserve one bird over the other, this is about conserving two species,” Lee said. “Spotted owls are fighting for their existence right now. Whereas, even if the service was able to remove that number of barred owls over the next 30 years, that would represent less than 1% of the global population of barred owls.”
Barred owls migrated to the Pacific Northwest from the Eastern U.S. and they’ve essentially outcompeted their smaller cousins. Spotted owls eat mainly flying squirrels, wood rats and red tree voles, while barred owls can eat salamanders, other mammals and birds, insects, or even snails and earthworms.
“They can use a smaller territory and they can pack into an area,” said Robin Bown, the U.S. Fish and Wildlife Service’s barred owl management strategy lead. “So the spotted owls become not just competing with a single pair of barred owls, but up to four pairs of barred owls to try to maintain their territory.”
While barred owl populations have grown exponentially since they arrived in the Pacific Northwest, “We are down to very few spotted owls left now in Washington and in Northern Oregon, and we’re rapidly reaching that condition in Southern Oregon and Northern California,” Brown said.
In previous studies, U.S. Fish and Wildlife Service found that in the study areas where barred owls were not killed, spotted owl populations declined by about 12% each year. In the places where barred owls were killed, there was only a 0.2% annual decline. Bown points out that because spotted owls only reproduce every other year or every third year, they didn’t have enough time in the length of the studies for their populations to rebound.
The agency has considered other methods of controlling barred owl populations, including sterilization and nonlethal removal. Both methods were considered impractical. Sterilization does not reduce the problem of competition long enough for the spotted owl populations to revive. “The population is not increasing because of that individual.,” said Bown. “But by the time the barred owl dies, the spotted owls in the area have also died, because they have no territories.”
Also, nonlethal removal would require caging or moving large populations of barred owls that have nowhere else to go.
“We don’t want to release these birds elsewhere in the West and spread the impact of this nonnative predator to other native species,” said Bown. “They prey on a large number of species that have a potential to have a pretty big impact on those species.”
When the U.S. Fish and Wildlife first started testing this method of species control, they hired an ethicist to help work through the moral issues of killing one species to save another.
Kessina Lee points out that since humans bear responsibility for barred owls being here in the first place, we also bear some of the responsibility for protecting the spotted owls. Initially, the Great Plains prevented barred owls from moving beyond the forested East Coast. But as European settlers planted patches of forest and changed the climate, the owls were able to migrate westward.
“When we’re talking about the likely extinction of a species, however unpalatable and uncomfortable the conversation is of lethal removal of another species,” Lee said, “people generally accept that this is sometimes necessary.”
You can listen to the whole conversation with Kessina Lee and Robin Bown on “Think Out Loud” by pressing the play arrow above.