2008-03-12_REPORT - C1982057 (2)

Home Browse Search

• The elevated densities observed in January 1998 (14.2 elk/mi2) and February 200 (10.8 elk/mi2) could not be explained by unusually deep snow, as snowfall was minimal in winter 1997-1998 and below average throughout the survey area and vicinity in 2004-2005. Conversely, the elk may have taken advantage of the lower snowfall to feed in grassland and sagebrush-grassland habitats within the survey area where forage is usually inaccessible in winter due to snow cover. As snow depths varied in both years (high versus average), the low number of elk observed in 2006 and 2007 (5.8 and 7.1 elk/mi2 respectively) may be more reflective of a decreasing local population, or a shift in overall wintering areas, than environmental conditions. Herds were widely distributed over the expanded area during each of the 14 surveys. However, herds were always conspicuously absent from the agricultural fields and grasslands in the northwest, north central, and southeast parts of the area. Although elk prefer to graze on grasses and forbs, snow cover over the low vegetation within those areas likely inhibited their use during the winter months. Consequently elk concentrated activities within habitats where ample forage (woody browse) was available above the snow-depth. • A total of 57 mule deer in nine herds were observed within the expanded survey area in 2007. Mule deer herds ranged in size from 1 to 13 animals, and averaged 6.3 individuals. Mule deer were observed in steep terrain on two portions of the expanded area, the south-central and northwest (Exhibit 1), and were exclusively associated with mountain brush habitats. Despite the observed fluctuations over the years, and omitting the December 1994 survey, mule deer densities in the expanded area have exhibited an overall increase since January 1995 (Figure 2). The lack of deer observations during the December 1994 survey was likely due to poor ground conditions and the use of a fixed-wing aircraft for the survey, as significantly more deer were observed in January 1995 during surveys employing a helicopter. Densities from l 995-2004 ranged from 0.27 to 0.76 deer/mil. Densities observed in 2005 and 2006 were more than twice what was observed in past years, with a record 1.92 deer/mil observed in 2006. The observed density in 2007 (0.64 deer/mil) was more typical of previous years. Regional population trends and the availability of forage in the general vicinity of the survey area likely influence the number of deer observed during big game surveys. Previous high densities of 0.75 and 0.76 deer/mil in 1997 and 2004, respectively, may also have been • influenced by the combination of those variables with above-average snow depth in the area. 2007 Seneca li-W Mine Wildlife Monitoring Page 6