With limited funds for conservation, researchers spar over which species to save—and which to let go

CANADA'S LAKE REVELSTOKE VALLEY—Even with round-the-clock attention and hand-gathered lichen for food, caribou calf 15 was doomed once it stepped from a pen here surrounded by 4-meter-high fences. That was clear as wildlife biologist Rob Serrouya crouched in the shadows of a grove of stunted yew trees a kilometer away from the pen and picked up the brown, nylon radio-tracking collar that once encircled the calf's neck.

Serrouya pawed through fallen needles on the forest floor, searching for clues. He lifted a finger to his mouth, tasting for the rusty flavor of blood. The researcher quickly uncovered four tiny shards of bone, still moist and pink. Those, and another telltale bit of bone in fresh bear scat, outlined the story.

A few days earlier, calf 15—3 weeks old and no bigger than a goat—had left the enclosure where it was born. Bound for meadows high in the Monashee Mountains, it faced a climb through a logged forest thick with alders and willows. The gauntlet was formidable to the calf, but an ideal hunting ground for a bear—a black bear, judging by the scat. And so the long struggle to save the Columbia North caribou herd, now down to about 150 animals, suffered another setback. "Major bummer," Serrouya said, gazing at the collar.

Preserving Canada's woodland caribou (Rangifer tarandus) is not for the easily discouraged—or for cheapskates. More than half of the herds, found in the mountains of western Canada and in the boreal forests across northern Canada, are in decline. In part, that's because many of the animals live in valuable old-growth timber or atop natural gas and oil, creating a strong temptation for people to encroach on caribou habitat.

The animals' plight has prompted a string of expensive, elaborate rescue operations. Here, for example, conservationists have spent nearly $2 million over the past 5 years to capture up to 20 pregnant Columbia North females each winter and helicopter them to the 9.4-hectare pen, where an electric fence protects them from predators. Managers release the newborn calves once they are old enough to have a better chance of survival.

Such desperate measures have had limited results. Although they have helped pause the downward slide of the herd, the population isn't growing. That has made it hard to avoid asking a painful question about the caribou—one that also applies to the more than 26,000 other species around the world that are threatened with extinction. Should people really try to save every population or species, or would letting some vanish—and focusing scarce resources on the ones that stand a better chance—be smarter?

Faced with a gulf between the species in need and the available resources, some scientists are pushing an approach that combines the cold-blooded eye of an accountant with the ruthless decisiveness of a battlefield surgeon. To do the greatest good, they argue, governments need to consider shifting resources from endangered species and populations that are getting too much attention to those not getting enough. That could mean resolving not to spend money on some species for which the chance of success appears low, such as the vaquita, an adorable small porpoise now down to fewer than 30 animals in Mexico's Gulf of California.

It's a controversial idea condemned by some scientists, who argue it is just oil on the already slippery slope to extinction. But government officials are showing interest. In New Zealand and Australia, they have already incorporated the approach into spending decisions. Canada and the United States are considering a similar move.

Even Serrouya, who works for the University of Alberta in Edmonton, Canada, and has spent much of his career studying the nation's woodland caribou, concedes that giving up on some herds is worth considering. But, "It's hard for me to swallow," he admits. "It's a hard one."

The term "triage"—from the French verb trier, meaning to sort—was born on the battlefields of Napoleonic Europe. Faced with a flood of wounded soldiers, French military doctors conceived of a system to decide who got medical attention and who was too far gone. The idea reached conservation biology as early as the 1980s. But in recent years it has moved from scientific journals to the halls of policymakers, thanks in part to an Australian mathematician and conservation scientist, Hugh Possingham.

In the mid-1990s, the former Rhodes scholar was at the University of Adelaide in Australia, teaching courses about using math to optimize economic choices. A devoted conservationist who grew up bird watching with his father, Possingham wondered whether that approach could be retooled to help save species.

Over the following decade, Possingham and others worked to create formulas that could point to the most efficient way to spend money on species preservation. They tried to quantify answers to key questions: What will species restoration projects cost? How likely are they to succeed? How distinct and important is each species? What actions will benefit multiple species or entire ecosystems, bringing the biggest bang for the buck?

Misdirected spending? The bull trout and a handful of other organisms protected by the U.S. Endangered Species Act get more money for recovery than recommended. But a 2016 study concluded that the vast majority, including the beautiful pawpaw plant, get far less. version="1.0" encoding="utf-8"? 0 100 200 300 400 500 600 Number of species Reptile Mammal Invertebrate Fish Bird Amphibian Plant Bull trout Average annual spending: $36,108,360 Proportion of recommended: 1637% Beautiful pawpaw Average annual spending: $4614 Proportion of recommended: 0.04% More Within range Less Actual recovery spending versus recommended:

Possingham, who last year became chief scientist for the nonprofit Nature Conservancy, headquartered in Arlington, Virginia, is fond of saying people engage in triage all the time. They weigh the available resources—such as time or money—and pick "the best things to do. That's all that everybody does all day, every day," says Possingham, who splits his time between Australia and the United States.

But it's a change from how governments often act. Today, conservation spending is influenced by a complex array of factors, including how close a species is to extinction and the pressure brought by lawsuits, lobbying, and media coverage. The result, Possingham and others argue, is that money is often poured into costly long shots or charismatic organisms, whereas species that could be secured for a relatively low cost go wanting.

A dozen years ago, New Zealand became the first nation to test Possingham's approach. A nation filled with unique species, some 3000 of them at risk, the country is a poster child for the extinction crisis. But New Zealand had no clear process for setting conservation spending priorities, recalls Richard Maloney, a senior scientist in the country's Department of Conservation in Christchurch.

In a bid to do better, officials asked Possingham to help craft a plan for spending roughly $20 million per year. The result was a list of 100 top-priority species, developed using a formula that balanced costs and benefits. In general, highly threatened species unique to New Zealand and ended up at the top of the list. But it also included representatives from a variety of species and took into account the cost and likelihood of success. Before that process, the government was working to recover 130 species. Now, more than 300 are getting attention, Possingham says. In Australia, the state of New South Wales followed suit, and advocates of the strategy say it helped persuade officials there to spend another $100 million over 5 years on conservation.

But for every species or population at the top of such lists, one is at the bottom. And that can lead to agonizing choices.

Canada's woodland caribou are a symbol of Canadian culture and a keystone for many First Nation peoples. But when humans move in, things don't go well for the animals. Forests cleared for logging, drilling, mining, or roads draw deer and moose that feed on the brush that grows back. The prey, in turn, attracts wolves and mountain lions. Caribou become collateral damage.

Serrouya has watched the results play out near his home in Revelstoke, a small town where workers from the local lumber mill rub shoulders with spandex-clad mountain bikers. Blackhaired and stocky, Serrouya evokes the black bears that frequent the craggy, surrounding mountains. Since the late 1990s, he has traversed those slopes on foot and on skis, documenting the lives of caribou and other wildlife. He has seen one nearby caribou herd plummet from 120 animals to just four and another drop from 36 to fewer than 15. About 30 kilometers north of Revelstoke, the Columbia North herd—the area's largest—appeared headed toward a similar fate, falling from 210 animals in the mid-1990s to about 130 by 2004.

To prop up the herd, conservationists have tried a little of everything. Officials banned logging on roughly half the forest. Hunters shot more moose, hoping to steer wolves elsewhere. Sharpshooters targeted wolves, killing 27 over the past 2 years alone. In 2014, a local nonprofit built the rearing pen.

But saving the caribou might mean keeping the species on life support for decades, Serrouya says. During a drive this summer through the herd's mountainous territory, he pointed to a stripe of light green beside the dark green old-growth forests; it looked as though someone had run a giant lawn mower across the landscape. That logged area is "still producing moose food," Serrouya said, and that means more wolves. He estimates the logged forest could take 20 years to grow back enough to make the area safer for caribou.

The dead calf he found later that day was the latest in a string of bad news. Three cows and two calves had died in the pen over the previous month, prompting fears that a heat wave was killing animals stuck at low elevation. "Under current conditions, even with no worsening habitat," Serrouya predicts the Columbia North herd is "on a trajectory to extinction" unless it gets major help. Farther south, two other herds are already on the brink, having dwindled to tiny single-sex groups—three females in one herd and four males in the other.

Caribou have it bad in Alberta as well. The neighboring province is the heart of the nation's oil and gas industry and is home to 12 caribou herds. Seven of those are in decline, according to a 2017 government report; another three have fewer than 100 animals. There, too, the government is taking extreme measures, shooting and poisoning more than 900 wolves since 2005. And it's considering building a massive enclosure to shield some of the 80 animals left in one herd, at a cost of as much as $15 million over 10 years.

Such schemes reflect the federal government's commitment, under Canada's Species at Risk Act, to save all the nation's caribou herds. But when Mark Hebblewhite, a caribou biologist at the University of Montana in Missoula, looks at how maps of woodland caribou habitat overlap with Alberta's oil and gas deposits, his response is: Get real. Hebblewhite doubts the government will ever summon the will to impose the development restrictions necessary to save all herds. He points to a 2010 study indicating that such restrictions could mean forgoing extraction of oil, gas, and timber worth more than $125 billion in Alberta alone.

All I’m saying is that we prioritize the winners. Mark Hebblewhite, University of Montana in Missoula

Instead of focusing on the most feeble herds, Canada should instead protect habitat in key areas where caribou populations still stand a good chance, he argued in a 2017 Biological Conservation paper. "We've prioritized the most screwed populations," Hebblewhite says. "All I'm saying is that we prioritize the winners."

That idea makes biologist Alana Westwood uncomfortable. A Vancouver, Canada–based scientist with the Yellowstone to Yukon Conservation Initiative, she acknowledges that money should be spent where it's most effective. But she fears that openly giving up on some herds cuts at the heart of endangered species laws. "It's really an existential question," she says. If Canada isn't willing to take the necessary steps, she suggests officials rename its law "the ‘recover species that are most easy to accommodate under business as usual act.’"

The caribou debate underscores one of the major difficulties of the triage approach. It's a lot easier—and publicly acceptable—to say which species or populations should get help than to announce which should be abandoned. That's one reason why scientists working in this field often prefer the term "prioritization" to triage. It's two sides of the same coin, Possingham says, but the feeling is very different. Politicians don't "tell you what they're not doing," he notes. "They would tell you what they are doing. Because politicians are not stupid."

Canadian officials, however, are starting to ask that once-unthinkable question: Is it worth funding efforts to save every species in need? In 2014, British Columbia officials asked experts to examine how it should spend money to conserve species in the southeastern part of the province. Using an approach similar to Possingham's, they estimated how 60 species would benefit from a menu of actions over 2 decades and how much it would cost. The caribou appeared to be a poor bet, with a less than 50% chance of recovering. A draft of their report dryly notes that "reallocating resources to species and ecosystems that will benefit from investment may need to be considered." In a sign of the sensitivity surrounding the issue, however, the provincial government never released the final analysis.

Nonetheless, some form of prioritization appears to be gaining support in Canada. In British Columbia, prominent conservation scientists are lobbying the provincial government to include a systematic way to rank the effectiveness of species recovery actions in environmental legislation it is crafting. At the federal level, officials in Canada's environment ministry are weighing a similar recommendation. In the United States, academics and federal wildlife officials are discussing ways to use those methods to rethink spending allocations for endangered species.

Such moves have alarmed critics—both scientists and environmental groups—who warn that the triage strategy is at best politically naïve and at worst a sneaky way to undermine species protection. "It's an easy way out for managers who don't have the balls to make tough decisions, and therefore we lose species after species," says Stuart Pimm, a conservation scientist at Duke University in Durham, North Carolina, who has often sparred with Possingham in public forums. One problem, he argues, is that giving up on a species also means abandoning a potent tool to rally the public and the courts. Sometimes charismatic animals such as California condors or polar bears can help build political support for saving endangered species or habitats more broadly.

And some species stand for entire ecosystems, Pimm adds. Consider the Cape Sable seaside sparrow. The innocuous songbird lives in Florida's Everglades, where water diversions threaten its marsh habitat. The species might not rank high in a triage system—in part because other populations of related seaside sparrows exist. But because of how the U.S. Endangered Species Act is structured, efforts to protect the sparrow have required policymakers to reallocate water, benefiting the entire ecosystem. "I'm afraid we have to make more complicated decisions than the simple recipes that Hugh comes up with," Pimm says.

Possingham concedes that triage is not suited to every situation. Europe, for example, has wealthy countries and few native endangered species, which makes saving them all realistic. And sometimes a species is so culturally important that it gets special treatment. New Zealand, for instance, has departed from its triage system to give priority to protecting 50 cherished species, including five species of kiwi birds, the nation's mascot.

But Possingham says opponents aren't acknowledging the nuance and power of a well-thought-out triage approach. One advantage, he says, is that using triage would make allocation decisions more transparent. Tight budgets already are forcing agencies in the United States, Canada, and elsewhere to ignore some teetering species, he argues—they just won't admit it. "I don't understand the con argument," Possingham says. "Why would you want to be inefficient?"

It's too early to say what a new emphasis on penny pinching might mean for the Columbia North herd. Ask Serrouya about triage for caribou, and he'll agree that it might be too late for some herds, especially where the forests are essentially gone.

But he is not ready to write off the herd he has monitored for so long. The Columbia North herd just needs to hold on—with more than a little help from humans—until the forest grows back and the moose and wolves move on. "There's hope, as long as we can hang on to these guys," he says. "Gotta have hope in this business."