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Are Yellowstone grizzlies ready for delisting?

A recent study of the bears’ diets has spurred a move toward ending endangered protections.


Pick up any newspaper in the Greater Yellowstone area during the fall, and you might get the impression that grizzly bears are on a collision course with humanity. Their numbers are growing, and they’ve been spotted in places where they haven’t been seen for generations. At the same time, whitebark pines, the bears’ prime fall food source, have been reduced to dead, red-needled forests in many places, thanks to an exotic fungus and bark beetles that are thriving in the absence of hard winters. In one study area, nearly three-quarters of the cone-producing trees died between 2002 and 2013. With whitebark pine nuts in short supply, managers often warn the public to be alert for grizzlies driven down from the mountains in search of food.

But the U.S. Fish and Wildlife Service hopes to change that grim narrative. According to a study by the federal government’s eight-agency grizzly bear research team, lead by the U.S. Geological Survey, the rapid decline of whitebark pine since the early 2000s isn’t the dietary disaster many predicted; so far, the bears are adapting. And since those dead and dying trees are the main thing keeping Yellowstone’s bears on the endangered list, the new study will likely be used as another volley in the battle over grizzly conservation.

Citing the new research, the Interagency Grizzly Bear Committee, a group of state and federal agencies charged with aiding grizzly recovery, recommended in late December that the Fish and Wildlife Service remove Yellowstone’s bears from the endangered species list. The delisting debate is now caught between two competing scientific narratives: Either the ecosystem is collapsing out from under bears, due partly to climate change (which is no good for whitebark pine), or else grizzlies’ built-in adaptability is helping them weather yet another change to their landscape. Whichever view prevails, whether on paper or in reality, it will have serious implications for the bears’ legal status. Beyond that, though, it will affect how managers and the public view climate impacts in one of the most intact ecosystems left in the Lower 48.

Since they were first listed as threatened in 1975, grizzly bears in and around Yellowstone National Park have increased from less than 150 to as many as 740, occupying at least 14 million acres today. Fish and Wildlife first delisted grizzlies in 2007, but after environmental groups sued, a district court ruled in 2009 that the agency had failed to fully consider the impacts of whitebark pine decline. Protections were restored, and a federal appeals court upheld the decision in 2011. But Fish and Wildlife contended that bears’ diets are varied and flexible enough to weather the whitebark decline; pine nuts have always been a cyclical crop. So the interagency committee directed the Interagency Grizzly Bear Study Team to begin reviewing three decades’ worth of grizzly research from the Greater Yellowstone ecosystem, the 20-million-acre region, consisting of the national park and adjacent state, federal and private land.

The Fish and Wildlife Service plans to make a decision soon on whether to draft a new delisting rule for public review – though if the past is any indication, court battles are likely to prolong the process. A new rule must show it’s not taking a “full-speed ahead, damn-the-torpedoes approach to delisting,” as 9th Circuit Court Judge Richard Tallman scolded in 2011. “The Service must rationally explain why the uncertainty regarding the impact of whitebark pine loss on the grizzly counsels in favor of delisting now, rather than, for example, more study,” he wrote then.

With more data now in hand and on the way, the researchers have concluded that the multitude of other foods grizzlies eat can replace piles of fatty tree nuts. If grizzlies are suffering from the loss of whitebark, researchers would have expected to see them expand their individual home ranges in search for food (which is different from overall population expansion due to their increasing numbers), and wake up skinnier in the spring. But neither appears to have happened.

Researchers with the Interagency Grizzly Bear Study Team (IGBST) and the National Park Service fit a grizzly bear from the Yellowstone area with a radio collar as part of an ongoing effort to study the bears and figure out why the growth in its numbers has started to slow. Once a bear is radio collared, researchers can track its movements with telemetry. Photograph courtesy Interagency Grizzly Bear Study Team.

Yellowstone’s bears eat over 200 different foods, ranging from high-elevation army cutworm moths and starchy biscuit root to ants and elk carcasses. Compared to bears in the mountains farther north, they are already big meat-eaters, but the study showed that they’re likely compensating for pine nuts by consuming even more meat, including insects. Evidence of bears feeding on carcasses in the fall doubled from 2002 to 2011.

Still, the population has been growing more slowly, inching up at a rate that ranges from close to zero to 2.2 percent per year, compared to 4.1 to 7.6 percent from 1983 to 2001. (Though even bear population numbers are subject to scientific controversy.) But scientists say that kind of leveling off is expected in slowly reproducing large carnivores, like bears.

The bear study team believes that the population growth is flagging – and that bears are invading new areas, like livestock-rich valleys with subdivisions –  because there are more bears now, not just because whitebark pines are dying. The bears started colonizing new areas in the ‘80s, before whitebark took a big hit.  Scientists blame decreased cub survival for the slowing population growth, and cub deaths are associated with high bear densities, not dying whitebark. That suggests that population growth is slowing and bears are living in new areas because they are crowded, not because they are hungry.

“Some people have said we are pulling the habitat carpet out from under grizzly bears in Yellowstone (given the decline of both whitebark and cutthroat trout), but I’m not sure I agree,” says Frank van Manen of the U.S. Geological Survey, the team’s leader since 2012. Whitebark, he says, is a valuable part of a “very diverse and dynamic diet.”

Some critics think the team’s conclusions align too conveniently with Fish and Wildlife’s long-time goal to delist. However, Chris Servheen, the agency’s grizzly bear recovery coordinator, thinks that keeping grizzlies listed in spite of their recent successes will erode support for them, and for the Endangered Species Act. Bear numbers now surpass 500, one of the many minimum benchmarks for considering the population recovered. Servheen fears that keeping them listed will make it harder to drum up public support for bears beyond Yellowstone, in places like the Selway-Bitterroot Wilderness, the Cabinet-Yaak ecosystem in Montana and Idaho, the Selkirk Mountains, and Washington’s North Cascades. "We desperately need more support of the ESA so we have political support to get it (funded) properly," he says. “There are many people who would like to see the ESA fail.”

Since delisting Yellowstone grizzlies would mean transferring management to Wyoming, Montana and Idaho, bear advocates worry that the recommendation to delist might be tainted by state officials’ long-standing desire to regain control of bears. While any delisting plan would maintain today’s habitat protections in the bear’s nearly 6 million-acre recovery zone, along with limits on bear deaths, the states will also likely begin bear hunting.

After grizzlies killed four people in the Greater Yellowstone region over a two-year period, Wyoming Gov. Matt Mead wrote then-Interior Secretary Ken Salazar in 2012, saying that two years was too long to wait for the results of the food study. Keeping bears listed (and thus harder for the state to control) threatened public safety, he implied. He added that Wyoming pays millions for bear management, yet has no jurisdiction over grizzlies. Salazar promised to consider delisting in 2014.

This makes David Mattson – whose work on the grizzly study team from 1979 to 1993 helped establish the links between bear behavior, population trends and whitebark pine – worry that politics have crept into the scientific process. “Science is politicized by the questions you ask and how you ask the question,” he says. Mattson, who was exiled from the grizzly world in the ‘90s for questioning delisting, is critical of the study’s methods, interpretations and motivations. He is especially displeased about the team’s unwillingness to release data to researchers outside the organization. (Van Manen says it’s because the large, complex datasets require historical background knowledge to use properly.)

Mattson and others also think the report doesn’t fully address the way increased meat-eating, especially of large animals like elk or livestock, could put bears at risk for lethal run-ins with people, should they venture down from high-elevation whitebark territory.

Meanwhile, the national environmental law group Earthjustice and the Bozeman-based Greater Yellowstone Coalition, which were involved in the earlier delisting suits, are waiting until the research project’s results have appeared in peer-reviewed journals and a new delisting rule has been published before they judge the food study or the pro-delisting vote.

Neither Earthjustice nor Mattson are convinced that bears can adapt to the climate and bark beetle-driven loss of whitebark without a cost. “These ecosystems are already changing, and the Yellowstone grizzly bear shows us how deeply this (climate change) issue will affect the potential survival of some of the things we really care a lot about,” says Tim Preso, an Earthjustice attorney for the Northern Rockies region.

If the impending delisting battle reinforces the view that grizzlies are climate change victims, it will help draw attention to the very real shifts happening in the ecosystem.  If grizzlies are in fact adapting, that’s good news, but it also means less iconic but struggling species will have to find their own way into the spotlight. The whitebark pine has yet to be added to the endangered species list.

Sarah Jane Keller is a contributor to High Country News. She tweets @sjanekeller.