U.S. Department of the Interior Secretary Ken Salazar shares Gov. Matt Mead’s desire to pull Endangered Species Act protections from Yellowstone grizzlies.

In a May 24 public letter to the interior secretary, Mead called for Salazar to speed a review of whitebark pine’s influence on grizzly populations, saying the protections cost Wyoming $2 million a year. In a July 19 response, Salazar said the U.S. Fish and Wildlife Service, a branch of the Interior Department, also wishes to “bring resolution to the grizzly bear issue quickly.”

The department’s Interagency Grizzly Bear Study Team is tasked with conducting research that will determine whether Greater Yellowstone Area grizzlies retain “threatened” Endangered Species Act status. In November, the 9th Circuit Court of Appeals prohibited the federal government from pulling protections.

The court upheld Judge Donald Malloy’s ruling that Fish and Wildlife failed to account for the potential harm to grizzlies from the decline of whitebark pine trees. The whitebark pine is in decline from pine beetles and blister rust, and its seeds are a critical food for the bear.

Salazar, in his letter, suggests the research is conclusive and there’s no such connection.

Biologists and statisticians have given “careful consideration and re-examination,” and “all participants agreed that the Yellowstone grizzly population was recovered and that declines in whitebark pine do not threaten the future of the population,” Salazar wrote.

Critics of the Interior Department’s push to remove protections, which could open the bruins to hunting, contend that science isn’t yet in.

In interviews about bear mortality, a critical factor in determining if grizzlies are delisted, study team researchers have echoed findings that support the interior security’s position.

“The bottom line is that the mortality that we’re seeing does not really cause any major concerns,” team leader Frank van Manen said. “These are not mortality levels that would lead to population declines.”

Unpacking mortality math 

Rates of natural grizzly mortality were elevated through May, June and July. Eleven of the 20 Greater Yellowstone grizzlies that met their ends this summer died of natural causes, van Manen said.

Historically, humans are to blame for more than 75 percent of bear deaths in the first half of the summer.

Because whitebark pine seeds are a fall source of food, it’s too early to say if the high-elevation conifer will influence this year’s mortality rate, the researcher said.

Because more bears are likely going to die before going into hibernation, it is also too early to say if the grizzly population, thought to be about 600 ecosystem-wide, can seasonably absorb the overall mortality rate, van Manen said.

The adult female grizzly and dependent cub populations can withstand about 9 percent mortality and the male population about 15 percent mortality, van Manen said.

“What we’re really most concerned about here is independent females,” van Manen said. “That is really the driving factor in the population.”

From 2002 to 2011, 49 percent of dependent female mortality was what bear managers call “unreported loss” — basically an extrapolation from uncollared bears that were reported dead. The remaining 51 percent of bear deaths are known.

In effect, because most grizzlies are not tracked, about half the study team’s estimate is based on guesswork.

Using the bear math, biologists found that independent females exceeded the 9 percent death ceiling three times from 2002 to 2011, most recently last year. In the same 10-year time frame, independent males exceeded the death limit four times and dependent cubs zero times.

The study team leader said there’s “no distinct pattern over time.”

Numbers game

Conservationists and critics say the mortality is not sustainable.

Louisa Willcox, senior wildlife advocate with the Natural Resources Defense Council, says the numbers are more significant than they’re made out to be.

“Three of the last four years, they have exceeded their own federally established limits,” Willcox said. “Either with males or females or both.

“The study team is part of the Department of the Interior, and the Department of the Interior is dedicated to delisting grizzly bears,” she said. “Of course they would downplay the significance of [the mortality findings].

“I think the internal pressure is somewhat incalculable,” Willcox said, “but it’s there. ...  You would be a fool inside the Department of the Interior to say that there’s a good reason not to.”

Dave Smith, a conservationist and author of bear books, takes the criticism a level further.

“Since 2007, the population has basically leveled off, but they keep saying that it’s growing 4 to 6 percent a year,” Smith said. “They know it’s leveled off, and the reason it’s leveled off is that they’ve got the mortality limits so high.”

Study team annual reports estimate that the grizzly population was 593 last year.

“Instead of fixing problems on the ground, all they’re doing is math tricks,” Smith said.