In a 1991 black bear management plan, Colorado Division of Wildlife bear researchers Bruce Gill and Tom Beck made experienced, qualified judgments on probable bear densities in varying vegetation types to arrive at a projection of Colorados bear population. Although bear densities varied considerably, by using an extrapolation of probable bear density over various habitats, Gill and Beck projected the bear population at 12,000 animals and density at one bear per five square miles statewide.
In two recent columns, Rep. J. Paul Brown suggests that preliminary results from an ongoing DOW hair snag study provides evidence for his claims that there may be four times as many bears now as there were in 1992, that there is little argument that black bear numbers in Colorado have increased exponentially in the last 19 years and that the study provides justification for increased hunting of bears (Herald, March 29 and April 5).
The study referenced, Non-Invasive DNA-Based Black Bear Density Estimates in Colorado 2009, (available at www.Bear SmartDurango.org), provides nothing of the sort. The study was conducted in an area with among the highest black bear densities reported in the Rocky Mountains, according to the studys authors. Although the hair snag surveys yielded a density of about one bear per square mile, the intentional sampling bias toward high bear density was made clear in the report.
Using one study and then applying the results statewide is flawed both scientifically and logically. The only population-related assumption one can make from this study would be the plausible bear density in similar high-quality bear habitats. Any other projections, including the far-fetched suggestion of a population of 48,000 bears statewide, based on this study, is either an erroneous interpretation or willful misinterpretation of the researchers conclusions.
Bryan Peterson, Durango