Those who study threatened and endangered species often speak with palpable loathing about the invasive critters eating their subjects. But not in the barred owl's case. There's just not a lot of eagerness to pick up the gun.

Anthony says he might support an experimental removal, but adds that he's discussed it with Forsman, and they both have reservations. "I guess we find shooting barred owls a bit distasteful," he says. "It's going to be hard for researchers to get permission and acceptance for a study like that."

Forsman agrees. "Unfortunately, my study areas are in the places where it would be most logical to do these kind of studies," he says. "I'm not looking forward to the controversy that would surround these studies. And I like owls. For me, it would be difficult to go out and shoot a barred owl." Forsman recalls another researcher, equally reluctant, telling him, "You know, Eric, we should really do this on your study site."

Even Diller, who sees some potential for killing barred owls as a management tool, had a hard time when Dumbacher pulled the trigger. He has spent 20 years detailing the habits of spotted owls. "You can't help but fall in love with them. And barred owls are just like them," Diller says. "I had to actually look away."

Sacrificing one animal for another is a long tradition in the United States, from the trapping of coyotes to the poisoning of ravens. In Alaska, wolves are shot to bulk up caribou numbers; in Utah, cougars are killed to protect non-native bighorn sheep. Historically, the government has generally culled predators to protect game species or livestock. It's only recently that agencies have begun trying to control one animal for the sake of another that is more endangered. But it's happening now with increasing frequency.

The day Wiens went out with Anthony, the Oregonian's headline read: "Sea lions apparently shot while in traps." For years, sea lions have been congregating in the Columbia River, chomping on spring chinook salmon as the fish linger in front of the fish ladders at the Bonneville dam. Sea lions also feast on winter steelhead returning to Lake Washington, and on other fish runs struggling to survive. Washington and Oregon sought permission to kill as many as 85 of the most troublesome sea lions, but were blocked in late April by a Humane Society of the United States lawsuit.

While waiting for a final court decision, the states rigged traps for the sea lions, preparing to ship the ones they caught to zoos and aquariums. Somehow, the trap was triggered unexpectedly, catching four California sea lions and two Steller sea lions, a species itself listed as "threatened." The first reports said the six sea lions had been assassinated. Then National Marine Fisheries Service investigators backtracked and said the trapped animals likely died of heat exhaustion when they couldn't escape into the water to cool down.

The quandary over what to do with the sea lions highlights the social and political ramifications of controlling one attractive native species to save another. Emotions have run high over the sea lions' fate, as well as that of the Caspian terns, which also gobble up Columbia river salmon, and of the golden eagles that once ate endangered Channel Island foxes. For days, the notion that someone with a grudge executed six sea lions seemed perfectly plausible.

The future of these animals -- the sea lions, the salmon and the owls -- depends largely on public opinion: the kind of biological future Americans envision for their country, and how much human interference they are willing to accept (or able to stomach). Flaunting its adaptability, the barred owl has colonized the city of Portland. One dropped into the Columbia River and was dredged out and picked up by a fishing boat. Another winged its way downtown and perched on the library sign. Dogs retrieve downy fledglings that have tumbled from the nest.

The barred owl has made itself at home. "It's not just a name and a picture in a book," says Bob Sallinger, conservation director for the Audubon Society of Portland. "They're very visible, so a lot of people have a personal relationship with this owl."

Sallinger, who got his start with Audubon at its wildlife rehabilitation center, knows this better than anyone. The owl in the river was one of many brought to the center. "All my personal experience to date with barred owls has been fixing them and releasing them back to the wild," he says.

This makes the question of killing them all the more difficult. People call him all the time, concerned because they've read newspaper articles about plans to shoot barred owls. What can they do to stop it? Sallinger tells them, "It's your right to say,  'Don't kill barred owls' ... but by doing that you may be making a decision to allow another species to go extinct." He advises callers to enjoy the barred owls in their neighborhoods, areas that aren't spotted owl habitat.

For Sallinger, the issue of habitat is still foremost, and neither the draft nor the final recovery plan provides enough of it. The arrival of barred owls means spotted owls need more protected habitat, not less, he says. In fact, the fragmentation of the forest may have helped the barred owl gain a foothold. "I think it would be outrageous and unethical to even consider killing another species until the underlying causes have been addressed. And they haven't."

But despite what Sallinger sees as a "cynical" twisting of the barred owl's role in order to free up more land for logging, the Audubon Society of Portland may ultimately sign off on lethal control. If the right plan came along, one that had scientific underpinning and specific targets and timelines -- and didn't involve trading away protected old growth -- Sallinger might support it: "I just don't think we can be in the position of saying no way, no how.

"It's fraught with ethical and moral and scientific issues," he says. But, he adds, "we would err on the side of avoiding extinction."

When people talk about killing barred owls, the terms "ethical" and "ethics" come up over and over. William Lynn, a professor at Tufts University and assistant director of the Center for Animals and Public Policy, advocates using ethics to improve policy. This is a challenge, as most recovery plans are focused on a short-term, immediate response to a crisis and don't engage the larger issues that an ethical decision might require. Many of the scientists interviewed for this article dismissed the questions of why the barred owl came West, whether humans paved the way and how, whether the bird should be treated as an invasive species or simply part of a changing ecosystem. But Lynn believes these issues matter, because they point to the still-unknown cause of the conflict. The spotted owl's decline is "a symptom of a much larger problem, and the problem is how we relate to animals and how we consider their well-being," he says.

According to Lynn, controlling barred owls would only make sense in terms of some larger commitment to change land-use policies. He believes Americans need to make some decisions about how we should live with other animals. Otherwise, we'll just face another emergency, with a different species, tomorrow.

As he steers the Jeep from the clear-cut vista, off to find another owl, Wiens comments, "Spotted owls are still doing well in parts of their range, so it's too early to be writing an obituary."

He mentions Tyee, a big study area just south of this one. But Anthony, the author of big demographic studies of spotted owls that come out every five years, contradicts him from the backseat: "Over the last three years, their occupancy rates have declined 15 or 20 percent," he says. "These occupancy rates have just continued to decline for all the study areas in Washington and the northern study areas in Oregon." Tyee was holding steady in the last report, but Anthony is preparing another demographic study in 2009, and the forecast looks bleak.

Near Cedar Creek, Wiens and Anthony walk down an abandoned logging spur, littered with shotgun shells and tangled with horsetail and blackberry bushes, heading toward a known spotted owl nest. Then they veer from the road down a steep slope. Luxuriant ferns and Oregon grape with its thick serrated leaves surrounding yellow blooms cover the hillside. Tall old-growth trees filter the sun. In the green light of the undergrowth, it's almost as if they are diving underwater.

Wiens points out a large, ungainly Douglas fir covered with moss. One branch juts out at a right angle, and other branches grow straight up from it, like the beginnings of new trees.
"They've nested in this tree the past three years in a row. It's a good spot for them," Wiens says. A little further down the hill, the male spotted owl peers down from a high cluster of three spindly Douglas firs.

Unlike the fierce, iconic wolf and bald eagle, the spotted owl seems an improbable candidate for the limelight. With close-set black eyes and dotted feathers, he looks more like a nearsighted math professor in flecked tweed than a diva. Needles and lichen tendrils obscure his face as he looks down to watch Wiens scoop up pellets and tie a pink plastic ribbon around the trunk, marking it as a roost tree.
This is the rare spot with no barred owls within a mile, one of only two of Wiens' sites where that's the case. Great horned owls -- one of the barred owl's only predators -- live nearby. They can prey on spotted owls, too, but haven't bothered this pair yet. Last year, these spotted owls raised two fledglings, and the female is warming new eggs right now. The male flicks out a wing and draws it back in. It's spring, and the earth is scurrying with things to eat. For the moment, the forest is quiet.

Kim Todd writes from Missoula, Montana. She is the author of Tinkering with Eden: A Natural History of Exotics in America.