Table 1 . Estimated potential population size of eight selected species 

 of wildlife on one oil shale tract in Colorado^ 



P(H)' p(L)2 



Estimated Estimated potential 



potential density population size 

 on tract on tract 



Superior Tract 



Mule deer 

 (Odocoileus hemionus) 



0.54 0.46 



35/nni2 

 (14/km2) 



364 



Elk 



(Cervus canadensis) 



Mountain lion 

 (Felis concolor) 



Golden eagle 

 (Aquila chrysaetos) 



Peregrine falcon 

 (Faico peregrinus) 



0.97 0.03 



Sage grouse 0.35 



(Centrocercus urophasianus) 



Mountain bluebird 

 (Sialia currucoides) 



Mallard 



(Anas platyrhynchos) 



9.7/100mi2 

 (4/100km2) 



0.77 0.23 7.9/100mi2 



0.22 0.78 



0.65 



0.87 0.13 



18/mi2 

 (7/km2) 



53/mi2 

 (20/km2) 



0.07 0.93 6/100ac 

 (15/100ha) 



0.8 

 (3/100km2) 



187 



551 



Read: The probability is 



that this tract supports, or under the 



P(H) 



set of environmental conditions described has the potential to 

 support, a high population density. 



species 



2 Read: The probability is 



that this tract supports, or under the 



fXL) 



set of environmental conditions described has the potential to 



support, a low 



species 



population density. 



favorable or unfavorable). The difference between the two sets of population esti- 

 mates would provide a measure of the impact of a negative change in habitat, or a 

 measure of the increased yield resulting from a favorable change in habitat (e.g., 

 through an enhancement management action). The change can be expressed as a 

 decrease or an increase in the number of animals on the tract. This difference can then 

 serve as the basis for formulation of a mitigation or enhancement production 

 objective statement. The above estimates should be viewed as relative rather than 

 absolute because of the many non-habitat conditions that also influence population 

 size. 



An additional use is to simulate one or more changes in habitat conditions to reveal 

 what environmental conditions would have to be changed and by approximately how 

 much in order to attain some designated yield objective. 



175 



