How the Barred Owl’s success in the Pacific Northwest is forcing managers to think the unthinkable
By Charles Bergman | Published: 10/1/2012
Big-eyed and sweet-faced, the Spotted Owl may be the most famous bird in the United States. It became the symbol of one of the defining environmental battles of the last century — the fight to preserve the last remnants of old-growth forests in the Pacific Northwest.
Now the unlucky bird faces a new and more desperate battle, one that has it staring straight into oblivion. The Northern Spotted Owl, Strix occidentalis caurina, is disappearing under an aggressive invasion by burgeoning numbers of Barred Owls, Strix varia. The future looks so dire that the U.S. Fish and Wildlife Service may kill thousands of Barred Owls.
“It’s a vanishing sight, rarer and rarer,” Dale Herter says. He and I are looking at a female Spotted Owl that has just materialized, silently and suddenly, from the old growth in the foothills of the Cascades, not far from Mount Rainier. She’s about 10 feet away from us. Black and huge, her eyes do not have the fierce glare of most owls. Instead, they are soft and darkly luminous. Her prominent facial disk amplifies a sense of openness, curiosity, and irresistible charm.
A wildlife biologist, Herter works for a firm that helps the U.S. Forest Service set harvests in timber areas. He has been studying the Spotted Owls here in Mount Baker-Snoqualmie National Forest for 21 years. “They could all be gone in a decade or two,” he says. “This time, I’m not sure anything can or should be done.” Then, in a dramatic tone that underscores how controversial the idea is, he adds, “Unless we kill all the Barred Owls.”
A male Spotted Owl tips off his perch, plunges downward, and seems to disappear in a flurry of blurred feathers and flailing wings. When the bird settles down, Herter holds him securely by his long legs. The owl’s eyes are closed in squinty slits. “They always relax after you catch them,” Herter says. “It’s like they go to sleep.”
Spotted Owls are famous for being tame, and this one had been caught trying to snatch a mouse out of the biologist’s bare hands. When the owl swooped in, Herter grabbed its extended legs.
The male is the mate of the female we’d been watching. Herter and his assistant, biologist Tracy Fleming, prepared to fit the owl with a radio transmitter so they could study the pair’s nesting habits. The research would also consider the birds’ home range, foraging areas, and population trends.
Since June 26, 1990, when the Northern Spotted Owl was listed as Threatened under the Endangered Species Act, it has been one of the most intensively studied animals in North America. Research like Herter’s revealed the owl’s dependence on old-growth forest — its canopies, prey base of voles and flying squirrels, and huge trees with big snags for nests.
At the same time, the owl was thrust onto the political frontlines. A century of timber harvests and clear cutting had stripped about 80 percent of the original forests of fir, hemlock, and cedar, sparking an outcry from environmentalists and multiple lawsuits. Jobs versus owls — those were the oversimplified terms of a fierce war in the forests.
The battle reached all the way to President Bill Clinton, whose forest summit led to the Northwest Forest Plan of 1994. It covered 24.5 million acres of forest and reduced annual timber harvests from 5.6 billion board feet in the 1980s to about 526 million board feet in 2004.
Loggers complained bitterly about losing jobs, but decades of unsustainable harvests were forcing the industry to restructure anyway.
Nevertheless, the owl continues to decline, at about 3.5 percent per year. In Washington, where home ranges are larger, the rate is much higher: 7.5 percent. Over the last 25 years, the U.S. Fish and Wildlife Service estimates that the population has dropped more than 40 percent.
Our three Spotted Owls
Three subspecies of the Spotted Owl exist between central Mexico and southwestern British Columbia:
Mexican Spotted Owl is found from southern Utah and Colorado through Arizona, New Mexico, and portions of west Texas into central Mexico. Lighter brown than the other subspecies. Listed as Threatened in the United States.
California Spotted Owl occurs in the Sierra Nevada, the southern Cascades, and in the coastal mountain ranges from Monterey to Santa Barbara. Brown with slightly larger white spots than Northern Spotted Owl. Not listed.
Northern Spotted Owl is a resident in southwestern British Columbia, western Washington and Oregon, and northwestern California. Darkest of the three subspecies. Listed as Threatened in the United States and Endangered in Canada.
After meeting Herter, I called Eric Forsman, the preeminent Spotted Owl biologist whose 1976 master’s thesis was the first major study of the species and raised the early alarms.
“We never had a good number for the total population of Spotted Owls,” he says. “We guessed maybe 3,000 to 4,000 pairs. Now, there’s a lot less than 20 years ago.”
They’ve virtually disappeared from British Columbia. In 1992, Wasington’s Olympic Peninsula had 150 birds; in 2009, it had 13. In the 1990s, the Wenatchee area of the eastern Cascades had 80 nesting sites; now 10 or fewer are known.
The situation on Herter’s study area is representative. After placing a small backpack and antenna on the male, he let the bird go, and it flew to a nearby cedar. The whole time, its mate had waited nearby, making a regular high-pitched whistle, ending with an upward inflection.
“That’s their contact call,” he says. The fidelity of the owls to each other is touching. They often keep the same mates for many years. This pair would try to nest this year, but their nest later failed.
As we headed back to the truck through late-spring snow, Fleming summarized 20 years of monitoring. “It’s an unremitting decline,” he says. “We used to have 127 owls in this area. Now, we might not have that many in the whole state.”
A slight exaggeration, perhaps, but it contained a painful nugget of truth.
The obvious suspect
The Barred Owl has been the obvious suspect in the continuing decline of the Spotted Owl. But until recently, the evidence was largely anecdotal. In March 2012, Dave Wiens, a wildlife biologist with the U.S. Geological Survey, completed his dissertation on the competition between Spotted and Barred Owls for territory and resources. It was a three-year, intensive study of about 350 square miles in Oregon.
“The Barred Owl is a major competitive threat to the Spotted Owl,” he tells me. Wiens conducted surveys of the same area that Forsman studied in the 1970s. “Even some of the same nests,” he says. Back in the 1970s, no Barred Owls were in the area.
“We found 82 pairs of Barred Owls,” says Wiens. “Only 15 pairs of Spotted Owls.”
“We know this,” Forsman says: “The Barred Owl is everywhere. Lots and lots and lots of them. It’s pretty much the case throughout western Oregon and Washington.”
Once considered an eastern bird, the Barred Owl has been moving into the Pacific Northwest for decades, crossing through Canada and dropping south. The first record for Washington was 1965; for Oregon, 1974; for northern California, 1981.
The Spotted Owl has narrow habitat and prey needs. In contrast, the Barred Owl is more of a generalist in both habitat and prey, giving it a major competitive advantage.
Plus, it’s adaptable. Wiens found Barred Owls can live on aquatic creatures in riparian habitats —crawfish, frogs, salamanders — as well as on the rodents prized by Spotted Owls. Their adaptability in prey means they need smaller territories and can achieve much greater densities than Spotted Owls. In the northern part of their range, Spotted Owls require larger territories, meaning that Barred Owls have an even greater advantage in numbers.
The smaller, passive Spotted Owl typically gives way to the invasion of the larger, much more aggressive Barred Owl. According to Wiens, Spotteds put up a game fight. But Barreds outnumber their smaller cousins four to one in many areas, leaving Spotteds simply overwhelmed.
Typically, Barred Owls harass nesting Spotted Owls, and things can get physical. Forsman saw one Spotted Owl blindsided by a Barred Owl. The usual result is that the Spotteds are displaced, chased off their nest and out of their territory.
Hybridization has also been reported. Forsman reviewed thousands of banding records and found 28 instances of hybridization. Male Barred Owls mate with available female Spotted Owls, producing offspring that look like a large, pale Spotted Owl. It’s a phenomenon on the leading edge of the invasion, and Forsman does not expect it to continue when female Barred Owls are more readily available.
What will happen, especially if nothing is done?
“We’re likely to see a long steady decline in the numbers of Spotted Owls,” Forsman says. “Even virtual extinction in the northern part of the range of Washington and Oregon.”
High-profile and controversial
“It’s a study, an experiment,” Robin Bown emphasizes. “We’re just trying to find out if it’s even possible to help Spotted Owls.” Bown, a U.S. Fish and Wildlife Service biologist based in Portland, Oregon, is the team leader for the project to remove Barred Owls from Spotted Owl territories. She is talkative, friendly, and eager to explain the plan, fully aware that it is high-profile and controversial. Make no mistake, in almost all cases, removal means killing large numbers of Barred Owls. Shooting them. In a few instances, however, birds may be captured and relocated or placed in permanent captivity.
“We just want to know if removal of Barred Owls is even a viable management option — if Spotted Owls will come back if their competition is removed,” Bown says. Her agency is now in the final stage of the approval process for the plan, deciding both whether to go forward and which of seven alternative plans it will employ. The experiment would begin in late 2013 and could last up to 10 years.
The service’s environmental impact statement identifies 21 areas from California to Washington where removal could take place, including national parks. The number of Barred Owls killed varies with each alternative, from 257 to 8,953. According to Bown, an option that has garnered particular attention would kill 4,006 Barred Owls.
Dan Ashe, director of the Fish and Wildlife Service, recently weighed in on the controversy. “We can’t ignore the mounting evidence that competition from Barred Owls is a major factor in the Spotted Owl’s decline,” he says, “and we have a clear obligation to do all we can to prevent the Spotted Owl’s extinction and help it rebound.”
I asked Wiens, an expert on both owl species, how he feels about killing one to help the other.
“It’s distasteful,” he says. “I admire Barred Owls. Personally, I grapple with this. But scientifically, the experiments are the only way we’ll know if we can help Spotted Owls. We don’t know if removal even works, if Spotted Owls will recolonize. The study would clarify these uncertainties.”
“I have serious concerns,” Forsman says. “We might learn something. But to work, we’ll have to kill thousands of Barred Owls forever. Or they’ll just come right back. We should not kid ourselves. To kill Barred Owls to answer a scientific question, when you won’t use what you learn to solve a problem in the long run…”
He pauses. “Well, it’s an ethical struggle.”
Witness to an invasion
No one can love Barred Owls more than Jamie Acker, a high school physics teacher on Bainbridge Island, across Puget Sound from Seattle. He’s a passionate owler. “We saw our first Barred Owl on the 1992 Christmas Bird Count,” he says. “Pretty quickly it was clear Barred Owls were moving in. I’ve been here to witness the invasion.”
Six years ago, Acker started banding the island’s Barred Owls. He knows all their family histories. Recently, he took me to see a new family.
We stopped at a thick stand of maples and alders, walked down a path, and found the female perched on a mossy branch. By her side were two fledglings, begging for food with insistent throaty wheezes.
“This mom is six years old,” Acker says. He banded her as a chick. She preened her offspring, an intimate family moment. She’s a successful mother, producing two to three chicks every year. Spotted Owls, Acker tells me, are lucky to produce one or two chicks every other year.
When I ask him about the plan to kill thousands of Barred Owls, he says, “Well, I love these Barred Owls. But they’ve taken over. The Spotted Owl in Washington could be gone in my lifetime, and that’s sad.” It’s not just Spotted Owls, either. He has watched Western Screech-Owls disappear on Bainbridge since Barred Owls arrived.
“At least your Barred Owls won’t be killed,” I offer, gesturing to the family in the mossy maple.
“These babies have to go somewhere for their own territories,” he says somberly. “They can travel 100 miles. One of my banded owls was found on the Olympic Peninsula.”
You’ve got to admire a creature as resourceful, adaptable, and successful as the Barred Owl. Still, it’s a grim revelation to think of the Puget Sound trough as a nursery, pumping out Barred Owls for an unending assault on the beleaguered Spotted Owl. It leaves us with a terrible choice, pitting two handsome and charismatic species of owl against each other.
Habitat proposal could hurt owls
A court-ordered revision of the federal government’s critical-habitat designation for the Northern Spotted Owl is due by November 15. A draft of the plan, published in February, drew quick disapproval from scientists and conservationists, who said it would undo protections for owls and other wildlife established in the 1994 Northwest Forest Plan.
In a letter to Interior Secretary Ken Salazar, the presidents of the Society for Conservation Biology, the Wildlife Society, and the American Ornithologists’ Union said the proposal has “the potential to adversely impact federal lands in the Pacific Northwest to the detriment of Spotted Owls and other federally threatened and endangered species.” The scientists especially oppose suggestions that would increase logging activities — referred to as “active management” in the plan.
The draft proposes nearly 14 million acres in California, Oregon, and Washington as critical habitat for the owl, yet the U.S. Fish and Wildlife Service said it may exclude up to 4.5 million of those acres that it says are already managed for conservation.
Steve Holmer, senior policy advisor for the American Bird Conservancy, says that while the amount of designated lands would provide good protections for the owl, he is concerned with provisions that could eliminate late-successional reserves managed under the Northwest Forest Plan — areas that are critical for the bird. In addition to maintaining the reserves, ABC has also called on the government to upgrade the owl’s status from Threatened to Endangered. — Matt Mendenhall
Charles Bergman is a professor of English at Pacific Lutheran University. In our June 2011 issue, he wrote about challenges facing the Tufted Puffin. And in our June 2004 issue, he wrote about the Yuma Clapper Rail and the birds of Skokholm Island.