Small Mammal Trapping 



The four small mammal live-trapping grids should be trapped for three 

 consecutive nights in April or May and again for three consecutive nights in 

 September or early October during the year immediately prior to the initiation 

 of mining and every third year thereafter until reclamation is complete. Eight 

 small mammal traplines (numbers 15, 17, 18, 20, 33, 34, 35 and 44) should be 

 snap-trapped each year for three consecutive nights in April or May and again 

 for three consecutive nights in late September or early October. Methods out- 

 lined in the baseline study should be used for all trapping. 



Lagomorph Survey 



The two lagomprph survey routes (map 3 ) snould be run consecutively on 

 each of three mornings in late September or early October of each year, begin- 

 ning with the mining area route at 4:00 A.M. 



SIGNIFICANCE OF IMPACT AND THE PROBLEM OF CAUSALITY 



A primary concern in monitoring is the documentation of impact and the 

 determination of the significance of the observed impact. Two special prob- 

 lems will arise here, and should be given consideration in the ultimate evalu- 

 ation of the proposed facility: (1) what, exactly, is a significant impact, and 

 how may it be distinguished from impacts which are not significant? and (2) can 

 a cause-and-effect relation be established between the proposed facility and any 

 impact observed? 



In determination of significance of impact, it is essential to recognize two 

 different components of the concept: biological significance and social accept- 

 ability. Biological significance can be measured by the scientist in terms of 

 changes in populations or carrying capacity. Social acceptability, however, is 

 dependent on tne degree to which a given impact "flaunts the public's (or por- 

 tion thereof) system of values" (Sharma et al.l975). Thus, while the deaths of 

 five mule deer may not be biologically significant, they may so outrage the public 

 that they assume a social significance which cannot be ignored. Similarly, des- 

 truction of a dozen burrowing owl nest sites can have a high biological signifi- 

 cance, but may be totally ignored by the public. While the ultimate impact 

 evaluation of the proposed facility must deal with both biological and social 

 significance of impact, this monitoring program was designed to deal exclusively 

 with the biological aspects of significance. 



It is suggested that the following definition of biological significance 

 be adopted: "an impact is significant if it results in a change that is measur- 

 able in a statistically sound sampling program and if 1t persists, or is expected 

 to persist, more than several years at the population, community or ecosystem 

 level" (Sharma et al . 1975). This is based on the assumption that "if an impact 

 is measurable, then a change detected by our crude schemes must be very large and 

 consequently significant." Thus, if the relative position of the black-billed 

 magpie sample abundance curve for the Dreyer Ranch changes after mining, and if 

 sample size is sufficient to establish statistical significance with p<0.05, a 



198 



