In a May 19 op-ed in the Salt Lake Tribune, Interagency Grizzly Bear Committee Chairman Harv Forsgren tried to play down the importance of whitebark pine seeds to Yellowstone grizzlies by stating, “Whitebark pines have been functionally extinct for 30 years in the Glacier Park/Bob Marshall Wilderness complex 150 miles north of Yellowstone due to blister rust disease, yet there are more than 900 grizzlies in this ecosystem and the population continues to expand at 3 percent per year without any whitebark pine seeds to eat.”
Is this an apt comparison? No. When U.S. Forest Service Chief Max Peterson tried a similar stunt in his comments on the U.S. Fish & Wildlife Service’s 1982 Grizzly Bear Recovery Plan, he was sharply rebuked for suggesting Yellowstone and Glacier have equal quality bear habitat.
Peterson wrote, “The disparity in our extrapolated bear numbers and densities between the Yellowstone Grizzly Bear Ecosystem and the Northern Continental Divide Grizzly Bear Ecosystem [same as the Glacier Park/Bob Marshall Wilderness Complex] is confusing. The two ecosystems are almost identical in size, yet meeting the population parameters established for recovery results 306 bears (1 per 28 sq.mi.) in the Yellowstone Grizzly Bear Ecosystem, and 650 bears (1/13 sq.mi.) in the Northern Continental Divide Grizzly Bear Ecosystem . . . We would like to see a better biological explanation of why population parameters resulting in such widely varying population numbers within each ecosystem were selected.” (p.169)
The response was, “Each grizzly bear ecosystem has its own unique set of population parameters reflecting different habitat conditions. The whole principal of our derivation of population goals was that such goals reflect the documentable characteristics of the population in the area. No ecologist should assert that a population with Yellowstone Grizzly Bear Ecosystem characteristics would constitute recovery in the Northern Continental Divide Grizzly Bear Ecosystem simply because there is no factual relationship between Northern Continental Divide Grizzly Bear Ecosystem habitat and the Yellowstone Grizzly Bear Ecosystem population parameters.” (p.190)
Ouch. It’s the habitat, stupid. Thirty years ago, biologists knew the Glacier Park area had better bear habitat than the Yellowstone region.
Recent research has once again made it clear there’s a significant difference between quality of grizzly habitat in Yellowstone and the Glacier Park/Bob Marshall Wilderness Complex. In 2004, biologist Kate Kendall did a DNA grizzly bear population census of the Glacier Park/Bob Marshall Wilderness Complex. The habitat supported 1 grizzly bear per 15 square miles.
In 2011, the Yellowstone grizzly population was 593 and the bears roamed over 22,000 square miles of land, so the habitat only supports an average of 1 grizzly bear per 37 square miles.
It’s troubling that Yellowstone supported 1 bear per 28 sq. mi. in the 1960s, but now only supports 1 bear per 37 sq. mi. That tell us habitat quality is declining. Why? If the loss of whitebark pine isn’t the problem, what is?