Small mammal trap lines were set according to techniques 

 adapted from Calhoune (1956) . Five lines were established 

 during the spring period while the same 5 lines and an addi- 

 tional 3 lines were set during fall (September) for a total 

 of 1,755 trap nights. Locations and descriptions of each 

 line are given in Appendix 15. Results of the spring and 

 fall trapping are presented in Table 8. Five trap lines 

 were established at proposed mine facility sites including 

 the tailing pond, well and substation, clarification pond, 

 lower mill and upper mill sites. Plans for the clarification 

 pond were deleted by ASARCO so that site represented a TSHE/ 

 CLUN habitat type. The other four sites had been logged to 

 various degrees. Three additional lines established during 

 September were located in habitat types proposed for mining 

 disturbance. Trapping success was in all cases better dur- 

 ing the fall than during the spring. 



Deer mice were the most frequently captured species at 

 all five spring trapping locations and at four of the eight 

 fall trapping locations (Table 8) . Of the six species cap- 

 tured in trap lines, deer mice comprised 4 3.5 percent of the 

 catch. During both spring and fall, the upper mill site 

 trap line showed the highest trapping success, with deer 

 mice comprising 5 8 and 30 percent of the catch for each 

 season, respectively. The THPL/OPHO site had the second 

 highest trapping success, with deer mice comprising 50 per- 

 cent of the total catch. The THPL/OPHO habitat type is pres- 

 ent along portions of the tailing slurry pipeline route. 



Capper's red-backed mouse was the second most commonly 

 captured species, comprising 2 8 percent of the total catch. 

 It was the most commonly captured species at the following 

 locations: upper mill site during both the spring and fall, 

 the lower mill site during the spring and the ABLA/MEFE 

 site (trapped only during fall) . Trapping success at the 

 THPL/OPHO habitat type site revealed it to be as important 

 as each of the previously mentioned sites although it was 

 second to the deer mouse in numbers captured. A single 

 heather vole was captured at the upper mill site during the 

 spring trapping period. Masked shrews and vagrant shrews 

 were captured at all eight trapping locations. More masked 

 shrews were captured than vagrant shrews although this may 

 have been a factor of trap susceptbility or trap location. 

 Similar to the other four species captured in trap lines, 

 shrews were more likely to be captured during fall than the 

 spring. The greatest number of shrews were captured at the 

 upper and lower ore milling sites. In general, greater num- 

 bers of small mammals were captured at moist sites than at 

 dry sites. 



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