BILLINGS, Mont. — Grizzly bears in and around Yellowstone National Park will keep their threatened status for at least the next two to three years, as wildlife officials said Friday they plan to bolster their case that the species has recovered.
Federal and state officials insist there are enough bears in the three-state Yellowstone region to guard against a reversal of the decades-long effort to bring them back from near-extermination.
That was put in doubt last fall, when the 9th U.S. Circuit Court of Appeals shot down an attempt by the U.S. Fish and Wildlife Service to remove protections for the animals. That would have returned grizzlies to state control in portions of Montana, Wyoming and Idaho.
The court ruled that Yellowstone grizzlies face a continued threat from the loss of whitebark pine trees, a key food source historically for some bears. The trees have suffered from insect infestations and disease blamed at least in part on a warming climate.
But government biologists say bears that once depended on the trees are switching to other foods, including truffles.
To prove that point, Fish and Wildlife Service grizzly recovery coordinator Chris Servheen said researchers plan to spend the next 20 months re-analyzing prior studies on whitebark pine and the role it plays in the grizzly population.
At the same time, officials will be crafting a new proposal to lift protections that could be issued in two to three years.
"We have to build a case we can get through the legal system," Servheen said Friday. "We feel that we will erode public support and agency support for grizzly bears the longer this legal interference goes on."
The Yellowstone region had an estimated 593 bears last year — a figure that Servheen and other bioligists say is likely an underestimate. Officials plan to use a new counting technique beginning this year expected to reveal the population is significantly larger.
To get a more accurate number, biologists who conduct annual surveys will no longer discount female adult grizzlies with cubs that are found within 30 kilometers of another female with cubs, officials said.
That was done in the past to make sure the same bears were not counted twice. But it is no longer considered necessary as bear densities have increased and more of the animals' territories overlap.
Last year's population estimate was down slightly from a record 602 bears tallied in 2010.
A representative of the environmental group said wildlife managers should proceed with caution as they consider the bears' future.
"Whether the slight decline is the beginning of a bigger decline or whether it will stabilize, only time will tell," said Louisa Wilcox with the Natural Resources Defense Council. "They have to deal with the court's issue of white bark pine. They can't just paper over the problem."
As the bear population has grown, so have conflicts with humans. That's led to increasing numbers of bears killed every year by hunters and wildlife managers.
Four people were killed by grizzlies over the past two years in Yellowstone National Park and nearby areas of Wyoming and Montana.
Grizzly bears were put on the list of federally-protected threatened and endangered species in 1975. The government has spent more than $20 million on efforts to restore the species.
There were 200 to 250 grizzlies when recovery efforts began in earnest in the late 1970s and early 1980s. The population grew at a rate of between 4 and 7 percent annually for most of the intervening years, leveling off to just 1 to 2 percent annually in recent years.
"We're undercounting dramatically the number of bears," said Greg Losinski with the Idaho Department of Fish and Game. "We need to manage this as a recovered species, as well as we need to be doing all we can to get the management over to the states."