2018-08-20_REVISION - C1980007 - Laserfiche WebLink

Home Browse Search

areas of Colorado, south of I-70. Most of the dens were in spruce/fir forests in areas of extensive downfall. Elevations ranged from 10,226 to 11,765 feet for 2005 dens (CDOW 2005a) with a mean elevation of 3354 meters (11,001 feet) for all dens prior to 2009 (CDOW 2009). However, the project area is all below the elevation where denning has occurred in Colorado. Lynx have been described as being generally tolerant of humans, including moderate levels of snowmobile traffic (Ruediger et al. 2000). In a lightly roaded study area in northcentral Washington, logging roads did not appear to affect habitat use by lynx. In contrast, a study in the southern Canadian Rocky Mountains found that lynx crossed highways within their home range less than would be expected (Ruediger et al. 2000). Lynx have been reintroduced to southwestern Colorado, beginning in 1999. Tracking of these lynx indicate that lynx are using or moving through the Forest, but only a few of the relocations lie within or adjacent to the project area (CDOW 2005). Of the total 218 adult lynx that have been released in Colorado, there are 115 known mortalities (CDOW 2009). The cause of death is unknown for a third of these, but the two leading known causes of mortality are starvation and being hit by a vehicle. Speed has been identified as the primary factor contributing to vehicle - wildlife collisions (Gunther et al. 1998). Neither is considered to be a factor for this project due to the lack of suitable habitat in the project area. There are no landscape linkage areas in or near the project area or any travel routes associated with the project. The Recovery Outline (USDI FWS 2005) identifies core areas, secondary areas and peripheral areas, based on historical and current occurrence records, as well as confirmed breeding. The Southern Rockies (Colorado and Wyoming) were identified as a Provisional Core Area. This designation was identified because this area contains a reintroduced population. Reproduction has been documented but it is too early to determine whether a self-sustaining population will result. A total of 37 dens and 116 kittens had been located in Colorado prior to the 2009 breeding season (CDOW 2009). In November 2005, the FWS proposed critical habitat for lynx (USDI FWS 2005a). In 2006 Critical Habitat for the lynx was designated, with none occurring in the Southern Rockies (USDI 2006). A revised critical habitat designation which does not include lands within Colorado has been proposed (USDI 2008). Extensive stands of pure aspen may not provide quality hare (primary prey) habitat due to deficiencies in winter habitat characteristics. However, when mixed with spruce/fir, aspen (especially younger stands) may substantially contribute to prey productivity (Ruediger et al. 2000). Lynx transplanted into Colorado were frequently located in well developed riparian and valley wetland shrub habitats of the upper montane and subalpine zones. These ecotones may provide quality foraging habitat for lynx. Sunset Lease Modification Biological Assessment 11