nort±» of Whitefish, Montana (approximately 35 miles east of the 

 impact area) for 7 years. During the course of their study they 

 estimated the following densities of black bears: 1960 - 1.0 bear 

 per 640 acres; 1961 - 1.25 bear per 640 acres; and 1966 - 0.6 bear 

 per 640 acres. In obtaining these estimates they used the total 

 land area, even though portions of it were known to be unsuitable 

 to black bears. High quality riparian habitat along the Kootenai 

 River probably supported a high density of black bears similar to 

 the 1960 estimate of Jonkel and Cowan (1971). Due to a more stable 

 food supply the black bear population probably did not undergo 

 severe population fluctuations and therefore the low value of 0.6 

 bears per 640 acres and the high value of 1.25 bears per 640 acres 

 were not used in the population estimates. Using a density estimate 

 of 1.0 black bear per square mile (640 acres) a population for the 

 terrestrial habitats (25,536 acres) was estimated at 40 animals. In 

 addition, the same density of black bears was assumed to inhabit the 

 Fisher River, Wolf Creek and Fortine Creek drainages which were 

 impacted by a loss of habitat related to the relocation of the 

 Burlington Northern railroad grade. 



4) Assessment of In pacts 



Formation of Lake Koocanusa inundated 28,850 acres of various 

 habitats, of which 25,536 acres were terrestrial habitats. Replace- 

 ment of these habitats with a large body of water had a negative 

 impact on the black bears inhabiting the impact area and adjacent 

 habitats. Inundation of 9,197 acres of high quality habitats (1,583 

 acres of grassland, 3,404 acres of sub-irrigated grassland, 667 

 acres of shrub riparian, 159 acres of upland shrub, 873 acres of 

 Cottonwood riparian, and 2,511 acres of mixed riparian) probably had 

 the greatest impact on the resident black bear population. Inun- 

 dation of these habitats resulted in the loss of preferred foraging 

 areas (Lindzey and Meslow 1977) and denning sites (Jonkel and Cowan 

 1971, Gillespie 1977). Inundation of 14,959 acres of conifer habi- 

 tats also had a negative impact on the black bear population. These 

 habitats may not have been as preferred as the grassland and ripar- 

 ian areas; however, they did provide habitat components known to be 

 used for foraging and denning. 



The inundated habitats also provided seasonal use areas for 

 black bears whose home ranges were primarily on areas adjacent to 

 the reservoir. Loss of the high quality habitat (grasslands and 

 riparian habitat) necessitated maintenance - foraging and denning - 

 of the bears on poorer quality higher elevational ranges, which 

 probably resulted in a reduced reproductive rate and reduced 

 survival of young (Rogers 1974) . 



42 



