How Many Grizzlies?
To understate it a bit, grizzly bears have certainly been in the news a lot this summer in North Idaho. Two widely publicized incidents have left two grizzlies dead, one hunter dead, and more white-hot debate over the very rare large carnivore. If there’s a universal lesson about anything this summer, it might be that human-grizzly interactions are dangerous for humans and grizzlies alike.
After retreating from 99% of their original habitat range, grizzly bears were listed as a threatened species in 1975 in the lower 48 states. Currently, grizzly bears are found only in a very few distinct areas in the western United States, but they include the Cabinet-Yaak range in North Idaho and northwest Montana, and the Selkirk mountains in North Idaho, northeastern Washington and British Columbia.
The number of bears in our two recovery regions is uncertain, but current estimates number from the several dozens to the several hundreds. To determine more precisely how many there are, a grizzly bear census may be coming to North Idaho next summer. Federal researchers plan to analyze DNA from hair samples captured at some 800 collection sites to be established across the Cabinet-Yaak Mountains in North Idaho and western Montana. Using DNA and mapping tools, researchers will be able to identify individual bears and their location. The 3-year study will cost more than $1.7 million.
A similar study in the region around Glacier National Park discovered more than twice the number of grizzly bears were roaming the area than were previously estimated. For this reason, much of the financial support for the North Idaho study is coming from some seemingly unlikely sources. Boundary County, Idaho and Lincoln County, Montana are chipping in. So too is Revett Minerals, which has mining interests in Troy, Montana, and has proposed the Rock Creek mine in the Montana Cabinet Mountains above Lake Pend Oreille. Why? Because if the study shows that the grizzly bear population is more robust here, then grizzly-related restrictions on mining and timber activities on federal lands eventually might be lifted.
But this research will provide only an initial baseline. Most important to bear recovery efforts will be the trend line over time. Is the bear population increasing or decreasing? Is the biological genetic diversity of the bear population improving or not? A single census, therefore, is unlikely to prove much about the species’ recovery, regardless of the number of bears found.
Moreover, the one thing that grizzly bear research in North Idaho is already very clear about is that the leading cause of death for grizzly bears in the region is human interaction (PDF). More than 50% of grizzly deaths in the Cabinet-Yaak, and 80% of grizzly deaths in the Selkirks are a direct result of human interaction. Categories of human-caused mortality used by researchers included defense of life, management removal, mistaken identity, poaching, train or automobile collision, and “unknown but human caused” in which bears were shot but researchers could not determine the circumstances of the death or incidences of cut off radio collars where no carcass was discovered.
So, for the safety of the humans and the recovery of the bears, regardless of the outcome of the census, human-bear interactions will still need to be managed very carefully.