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coulee because of the possibility the area might hold unique species not found 

 in the other types. Exact locations of all small mammal trap lines appear in 

 Appendix Table 19. Each line consisted of 25 stations 10 m apart with 1 sunken 

 can pitfall (dia. 15.5 cm), 2 snap traps and 1 Sherman live trap at each station. 

 Snap traps and live traps were baited with a 50-50 mixture of peanut butter and 

 rolled oats. Pitfalls contained approximately 3 cm of water to drown the small 

 mammals captured. Trap lines, once set, were checked daily for a minimum of 5 

 consecutive days. Species, sex, standard body measurements, station number and 

 trap type were recorded for each specimen. Testes, ovaries, and the uterine 

 horns were examined macroscopically for evidence of reproductive activity. Snap 

 traps that had been sprung and live traps closed without captures were also 

 recorded. Traps were checked as early in the morning as possible to retrieve 

 specimens before decomposition became severe. All unidentifiable or unique 

 specimens were frozen for later identification. Study skins were prepared 

 and skulls were cleaned for representative specimens of all species captured. 

 Specimens were deposited in the Department's nongame mammal collection in Bozeman. 



Fall small mammal sampling was conducted during the last week of October using 

 methods similar to those employed by Matthews (1979). During the fall season 

 only one line was placed in each of the four major vegetation types. Each 

 line consisted of 25 stations 10 m apart with three snap traps and one Sherman 

 live trap per station. In addition one of the snap traps at every third station 

 (i.e. 1, 4, 7, 10...) was replaced with a Victor rat trap. Peanut butter and 

 rolled oats wereused for bait and fall trapping was terminated after three 

 consecutive days for each type. All specimens and data were handled in the same 

 manner as previously reported for the summer survey. 



The number of nonfunctional traps (snapped or closed without capture) was sub- 

 tracted from the total number of trap nights before calculation of the number 

 of captures per 100 trap nights. 



Other Wildlife Species 



All observations of nongame wildlife on the study area, whether direct or 

 indirect (tracks, scats, etc.), were recorded. For each observation, the 

 date, time, species, location, vegetation type, age, sex (if possible), total 

 number and activity were recorded. Wildlife identification was aided by 7 x 35x 

 binoculars, a 35x spotting scope, various field guides (Burt and Grossenheider 

 1964, Robbins et al. 1966, Stebbins 1966, Murie 1975), and cassette recordings 

 of bird songs. 



Unusual specimens of reptiles and amphibians encountered during travel of the 

 area were collected and preserved in a 10 percent Formalin solution for later 

 identification. 



Bats were collected using 1.3 cm mesh mist nets and a 20 ga. shotgun. Most 

 collecting occurred near water sources (stock tanks, ponds, etc.) at dusk. 

 Nets were left in place and checked regularly for a period of four hours. 

 Gunning terminated approximately one hour after sunset. For all bats collected, 

 the sex was determined and standard body measurements were recorded. Specimens 

 were then frozen for later identification. 



Other species of small mammals such as cottontail rabbits {Sytvilagus spp.) and 

 thirteen lined ground squirrels {Spermophilus trideGemlineatus) were collected 

 with a .22 caliber rifle for species identification and verification. 



