Cottonwoods 



Cottonwoods occur only as isolated groves or individual trees in the mine 

 study area, and do not represent a well -developed riparian forest of the kind 

 found along the Missouri River and Prairie Elk Creek. However, they do provide 

 important hunting perches for raptors and nest sites for many species of birds. 

 Since cottonwoods are rare in the proposed mining area, care should be taken to 

 preserve or replace them. 



SPECIES OF SPECIAL CONCERN 



Raptors and Their Prey Base 



Perhaps the most unique and remarkable feature of the fauna of the mine 

 study area is its unusual variety and density of raptors. Six species are known 

 to nest on or near the proposed mining area, and an additional seven species have 

 been observed at some time on the proposed mining area (tables 7, 9). Part of the 

 attractiveness of the area to raptors lies in the local abundance and diversity of 

 prey species. Small mammals, lagomorphs, and small birds are abundant on and near 

 the proposed mining area, and a prairie dog town is located within the mine study 

 area. Winter concentrations of rough-legged hawks and golden eagles have been 

 observed along Nelson Creek within the mine study area. 



Game Species 



While densities of big game, upland game birds, and waterfowl in the mine 

 study area were not remarkable, these species merit special concern because of 

 their high economic and recreational importance. Of these species, those having 

 sizeable populations within the proposed mining area are the mule deer, pronghorn 

 antelope, and sharp-tailed grouse. Populations of other game species were rel- 

 atively small . 



Endangered Species 



The occurrence of two endangered species, the bald eagle and peregrine fal- 

 con, has been documented on the proposed mining area. Both species are believed 

 to occur as migrants or visitors, rather than residents, and were seen only rarely. 



While the proposed mining area lies within the historic range of the endan- 

 gered black-footed ferret, it is unlikely that this species occurs here, where no 

 suitable habitat exists, or in a small prairie dog town within the mine study 

 area. The most likely area in which this species may occur is within the CM. 

 Russell National Wildlife Range along the southern end of Big Dry Arm and along 

 lower Big Dry Creek, where prairie dog towns are abundant. These areas were not 

 searched for ferrets during the present study, although possible ferret sign has 

 been reported by the U.S. Fish and Wildlife Service (Shupe, p.c.) 



Threatened Species 



192 



