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leucoc~halus) also seasonally occupy habitats on Rabbit Mountain. • The habitat affinities of virtually all these species allow them to utilize similar habitats on the Dowe Flats project area. The extensive prairie dog colonies on and adjacent to the project area are especially important for breeding golden eagles (Aquila chr saetos) and wintering bald eagles and ferruginous hawks Buteo regalis). The impact of reservoir development on prairie dogs and raptors will be one of the significant wildlife issues associated with this project. SMALL MAMMALS Burrowing mammal communities are important prey species for terrestrial and avian predators and their burrows provide shelter and/or rest sites for species ranging from tiger salamanders (Ambystoma ti rinum) and bull snakes (Pituophis melanoleucus) to cottontails Sylvilagus spp.) and burrowing owls Athene cunicularia). A recent small mammal survey of Rabbit Mountain captured only- 3 small mammals in 500 trapnights (where 1 trap open for 1 night = 1 trapnight). The results may have been a reflection of unfavorable weather conditions rather than a depauperate small mammal community (Boulder County 1984), Regardless, little quantitative data are available for local small mamal populations. Appendix B lists small mammals which may occur on Rabbit Mountain. Most members of an area's small mammal community are difficult to document without intensive trapping programs. Although no such programs have been undertaken on the project area, black-tailed prairie dogs (Cynomys ludovicianus) are, unarguably, the dominant small mammal species in terms of biomass. Mr. Dick Antonio completed a June 1987 survey of prairie dog towns on the project area and documented 3,142 active holes in 869 acres (HRM 1987). Approximately 580 acres on the east side of the limestone outcropping were poisoned in 1986-87 resulting in a 30-408 reduction of prairie dogs. CDOW 1041 (1977) distribution of prairie dogs in the vicinity of the project area is illustrated in Figure 2 along with prairie dog distribution (1984) on the Rabbit Mountain Open Space (Boulder County 1984). While the intensive and current work of Dick Antonio supercedes these data, they are provided for historical and other purposes. FORBEARERS AND PREDATORS CDOW 1041 wildlife distribution mapping lists beaver (Castor canadensis), Abert's squirrel (Sciurus aberti), black bear Ursus americanus), and mountain lion Felis concolor) as occurring in the vicinity of the project area. The St. vrain Creek is listed as part of the overall beaver distribution, although • 6