area. FWP anticipates these units will be mountain ranges or groups of ranges similar to those 

 currently used for black bear management. However, if information from bears outside the PCA 

 indicates a change is required, the units will be modified as needed. These units will be created 

 solely for the collection of demographic data and will not of themselves generate any new habitat 

 restrictions. 



In order to maintain consistency in data collection and compare grizzly bear population 

 parameters inside and outside of the PCA, monitoring protocols will be similar, but the sampling 

 may vary depending on the survey area. Monitoring of unduplicated females with young may be 

 used as an index to assess population trend or abundance over time. The data are currently used 

 to estimate a known minimum and total population size for the PCA. The number of 

 unduplicated females are summed over a 3-year period and divided by the known percentage of 

 females (27.4%) in the population to achieve a minimum population estimate. It should be noted 

 that this is a very conservative approach to assessing this population parameter. This minimum 

 population estimate has been used to set mortality thresholds for all human-caused mortalities. 

 The data can also be used to generate a total population estimate. The IGBST has evaluated 

 different statistical approaches and monitoring techniques that will allow agencies to estimate 

 total population size for this population of bears. FWP will continue to review this information 

 and use it and other data in the ongoing management programs. 



Radio-marking techniques to estimate population size are not broadly applied outside of Alaska 

 because of the expense associated with capturing bears within heavily forested habitats where 

 bears can't often be spotted from an aircraft. Many researchers in Canada and the United States 

 are focusing on "hair-snaring" techniques to estimate number and density of grizzly bears. With 

 this procedure, bears are attracted to sampling stations with a scent lure. At each sampling 

 station, barbed wire is strung between trees and when the bear passes under the wire, a small tuft 

 of hair is snagged. The follicles from these hair samples contain DNA, which can be used to 

 identify individual animals. This technique is conceptually similar to techniques developed to 

 identify bears based on photos taken when bears trip cameras. Advantages of the DNA and 

 camera techniques include reduced need to mark bears or see them from aircraft. However, 

 these techniques are labor-intensive, expense, and typically have problems identifying the area 

 inhabited by the estimated population. This closure problem creates difficulties in estimating 

 density. So far, the DNA and camera techniques are not standardized for design or data analysis, 

 hence results from different areas may not be comparable. In Glacier National Park, U.S. 

 Geological Survey researcher Kate Kendall has conducted the most extensive effort to estimate 

 grizzly bear abundance using hair-snaring and DNA analysis. Although her research is in 

 progress, she has identified a minimum number of different individuals (>200) in Glacier 

 National Park and vicinity that is larger than previously suspected. 



Estimates of density frequently have problems associated with differential inclusion of age or sex 

 groups. Because newborn cubs have high mortality rates, estimates made early in the year will be 

 larger than estimates made later in the year for the same population. Closure problems may 

 result in overestimation of males, the more mobile sex, in a density estimation area. FWP, when 

 attempting to estimate bear density, will be aware of these sources of potential bias and specify 

 which sex and age groups occur in density estimates. With DNA hair-snaring techniques, efforts 

 are made to exclude cubs by setting the barbed wire too high to snag their hair. Regardless, 



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