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 and expensive. In Glacier 

 National Park, USGS researcher Kate Kendall has conducted the most extensive effort to date to esHmate 

 grizzly bear abundance using hair-snaring and DNA analysis. This approach has expanded to include 

 the entire NCDE. Although her research is still ongoing, she has identified a minimum number of 

 different individuals (>200) in Glacier National Park and immediate vicinity that is larger than previously 

 suspected. 



Density estimates 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, some cubs leave hair samples behind, and some 

 bears greater than 1 year old may be able enter under the barbed wire without leaving hair. The age of a 

 bear is not revealed by DNA analyses. The capture-mark-re-sight technique used in Alaska avoids most 

 of these problems, but is useful only in areas where bears may be readily seen and may be difficult to 

 applv in habitats with a forest overstory. 



Trapping and radio collaring techniques provide necessary data on grizzly distribution, movements, and 

 home ranges. Data collected will include estimation of seasonal, annual, and lifetime home ranges, 

 identification of important seasonal habitats and foods, potential travel or linkage corridors, mortality 

 estimation, extent of occupation, and denning sites. Distribution of bears will be determined by using 

 any or all of the following methods: hair corrals, observation flights, telemetry flights, conflict activities, 

 and verified sightings. 



Population Trend Monitoring 



Survivorship data will be obtained via aerial, satellite, and ground telemetry of radio-collared bears. 

 These data are used to determine average life expectancy by sex and age class, causes of mortality, etc., 

 for bears that inhabit different portions of the ecosystem. All suspected human-caused mortality will be 

 investigated by FWP personnel to determine cause of death. These mortalities will be recorded and the 

 information used, along with other mortality data, in the management of the population. This 

 survivorship information will be fimdamental to addressing the issue of the potential differences in 

 survivorship of grizzly bears in the recovery zones, where there are extensive habitat protections, versus 

 bears that live on multiple use areas outside the recovery zones. 



Population Monitoring Guidelines 



FWP recognizes that any one factor cannot provide the needed information to assess population status 

 and trend. Ultimately, assessments will require multiple sources of information. In order to affectively 

 assess the status of the grizzly bear population in western Montana, the following will therefore be 

 monitored and reported annually. These data will provide a means of assessing population health, 

 determining population changes and will guide management decisions. 



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