Whitebark pine cones yield nutritious nuts grizzlies devour prior to denning, but even without pine beetles killing them, the trees don’t yield nuts every year.
Shoshone National Forest totals 2.4 million acres, including approximately 217,000 acres of whitebark pine. A 2011 aerial survey showed approximately 80,000 acres were impacted by mountain pine beetle. By including surveys from previous years, it is estimated between 60 to 80 percent of the mature whitebark pine have been impacted by the beetles.
“They identify trees impacted by looking for red-needled trees, which indicate the tree is dying or dead,” said Joe Harper, wildlife biologist for Shoshone National Forest.
Separate, smaller surveys of whitebark pine cones are conducted on the ground every summer at 22 transect lines in the six divisions of the national forest of the Greater Yellowstone Ecosystem, and the findings reported to the Interagency Grizzly Bear Study Team. The surveys help the team and forest managers understand the extent of beetle-caused whitebark mortality in the ecosystem, Harper said.
Shoshone has two transect sites of 10 trees each in Sunlight Basin and near Cooke City, Mont. Shoshone personnel have been surveying whitebark at those sites — Sunlight and Republic Creek — since 1980.
Grizzlies will do fine without whitebark, said Mark Bruscino, statewide supervisor of the large carnivore management section of the Wyoming Game and Fish Department.
“The whitebark issue that we are going to resolve in the new delisting rule will not have much of an affect on the grizzly bear conservation strategy or Wyoming’s state plan,” Bruscino said during a phone interview on July 26.
U.S. Interior Secretary Ken Salazar, like Wyoming Gov. Matt Mead, said he wants to end federal protections for Greater Yellowstone Ecosystem grizzly bears.
In an Associated Press story, Salazar said he anticipates delisting by 2014. He said two weeks ago whitebark declines do not threaten the recovered grizzly population.
Key foods for grizzlies are whitebark nuts, cutthroat trout, winter-killed ungulates (deer, elk, etc.) and army cutworm moths. Although cutthroat populations have declined, the grizzly population remains stable, Harper said.
“Whether their survival hinges on this one crop (whitebark) would be surprising to me,” he said.
The latest grizzly population estimate in the Greater Yellowstone Ecosystem is 600-plus grizzlies. That is recognized as a conservative estimate, but the interagency team is working on a new method to obtain a more accurate number, said Shoshone National Forest Wildlife Biologist Andy Pils.
Harper and Pils conducted this year’s survey Wednesday, July 25. On their way, Harper stopped to examine midden — a whitebark pine cone cache — on a forested hill above Republic Creek, with Gallatin National Forest south and Yellowstone National Park to the north. Squirrels bury the cones, then a grizzly unearths them, Harper said.
Gopher-like holes in the spongy duff are evidence of the grizzly’s excavations.
“(Grizzlies) sit right here and gorge themselves, thanks to the red squirrel,” Harper said.
The ripened cones won’t drop. Squirrels remove them, and Clark’s nutcracker birds pick the cones apart in the branches, Pils said.
As though on cue, a squirrel scampered past a couple packs on the ground and disappeared beneath a log. The squirrel remained mute, but the nutcrackers in the trees squawked like New Year’s Eve noisemakers.
Above the midden, the men began their survey. The 10 trees are blazed with a capital T, and an aluminum tag about the size of a silver dollar tells the tree’s number.
Because cones are hard to spot, Harper, Pils and Shoshone National Forest Silviculturist Jason Brey use binoculars to count the ones clinging to the trees’ branches.
The men looked for signs of beetle attacks and blister rust.
Although widespread, rust is not causing a lot of tree deaths. Pils said his greater concern is the beetles.
No. 4 is the only transect tree hit by beetles, but it is ailing, and other trees around are infected.
“It will be dead by next year,” Pils said.
The men scrabbled further up the hill, seeking another survey tree. Again, Harper paused. A nutcracker or squirrel likely misplaced a nut, resulting in a healthy whitebark pine about 18 inches tall.
“Here is the next generation,” he said.
Beetles are a native species, and whitebark have suffered them before. Evidence of new trees would suggest whitebark is not doomed, Bruscino said.
There is a lot of work determining what grizzlies are eating in areas around the ecosystem where whitebarks have been devastated by beetles. A lot of data has been collected from bears caught in traps. Grizzlies will survive without whitebark, Pils said.
Both survey sites, Sunlight and the Republic, averaged 12 cones per tree. Pils called that a moderate crop.
The forest service has safeguards in place for grizzlies such as the grizzly bear recovery area in the national forest, Pils said.
For example, there can be no new oil or gas pads in the primary conservation area of the national forests surrounding Yellowstone. And motorized travel is limited to levels that existed in 1998 when the grizzly population was considered recovered, Harper said.
Wyoming has a 2006 grizzly management plan. The state will make any revisions to that plan necessary to support the delisting rule, Bruscino said.
“Yeah,” Pils said. “I think it is time to let it happen.”