SUMMARY 



Wildlife communities were investigated in McCone County from June 1976, to 

 February 1978, with emphasis on the Circle West lignite mining area proposed by 

 Dreyer Brothers, Inc. Habitat data were gathered in conjunction with a concurrent 

 vegetation baseline study. Data on distribution, habitat use, and population 

 characteristics of big game, predators, raptors, upland game birds, and waterfowl 

 were recorded on standardized data sheets during ground and aerial surveys. Five 

 39.4 km (24.5 mile) roadside wildlife survey routes were established to sample 

 vertebrate communities in a variety of habitats, and most were run monthly in 

 1977. Censuses were taken of breeding bird communities on two 25 ha (62 acre) 

 grassland plots, two 25 ha (62 acre) coulee plots and one 24 ha (59 acre) silver 

 sagebrush plot. Small mammal communities were sampled throughout the summer in 

 four 10 X 10 live trap grids (9200 trap-nights), 24 snap-trap lines each having 

 50 traps at 25 stations (7200 trap-nights), and 7 pitfall trap grids each having 

 8 trapping stations. Two lagomorph survey routes: were established and run three 

 times in October 1977. 



Predominant habitats in the study area were grasslands (dominated by blue 

 grama, needle-and-thread, and western wheatgrass), cultivated land (primarily 

 sown to wheat), and sagebrush shrublands (dominated by silver sagebrush on flat- 

 ter sites and big sagebrush on broken, upland sites.) Trees were abundant only 

 in the riparian cottonwood forest along the Missouri River and near the mouths 

 of major streams, although scattered farm groves and isolated cottonwood groves 

 occurred throughout the area. Extensive badlands, characterized by steep, deeply 

 dissected topography and by much bare soil, mudstone, and siltstone, were found 

 along the Big Dry Arm of Fort Peck Reservoir, which was the largest water area 

 in the region. Other wetland habitats were limited to scattered stockponds and 

 a few permament streams and marshes. Deeply-cut coulees near the heads of drain- 

 ages supported dense strands of tall shrubbery, especially silver buffaloberry, 

 chokecherry, serviceberry and occasionally red-osier dogwood. These tall coulee 

 shrubs were of limited extent but were especially valuable to a number of wild- 

 life species. 



Data were obtained for 4 species of amphibians, 7 of reptiles, 139 of birds, 

 and 26 of mammals observed during the study period. 



The predominant breeding waterfowl species were found to be the mallard, 

 American wigeon, blue-winged teal. Breeding populations, especially the pintail, 

 were quite low during 1977 due to the abnormally dry spring. Larger, older 

 stockponds bordered by marsh or shrubs were found to provide the most suitable 

 breeding habitat. 



The study area was found to support an unusual variety and density of raptors, 

 and nests of the golden eagle, prairie falcon, red-tailed hawk, ferriginous hawk, 

 marsh hawk, and American kestrel were found on or near the proposed mining area. The 

 high densities of small birds and mammals found in the area appear to be an attrac- 

 tive prey base for raptors at all seasons. The endangered peregrine falcon and 

 bald eagle were observed on and near the proposed mining area, but are visitors 

 there rather than residents. 



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