2008-09-29_PERMIT FILE - C1981019A (5)

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RULE 2 PERMITS observations and location of the transect are summarized in Table 2.04.11-8, Wildlife Transect Obser- vations and on the Wildlife Observations Map (Map 15). Rodent Studies The purpose of the rodent studies was to determine densities of rodents within the various habitat types on the site. From the data collected, the diversity, density, and the potential influence by rodents on the revegetation program were evaluated. Small mammals (rodents) were sampled using two methods.' First, two grids each 120 by 135 (72 traps) were set on two different locations on the site. Grid No. 1 was located in sagebrush-grass habitat type. The conditions at this site were conclusive to a large rodent population. Grid No. 2 was located. near -the revegetation study plot, the sagebrush-grass-serviceberry type of less quality. The grids were trapped for five consecutive night using oatmeal as bait in the traps. Rodents trapped were eartagged using Monell No. 1 tags for positive identification and released. Records of the species, age conditions, sex, trap location and capture - recapture were kept. From these data, species diversity and densities were calculated. This information is set forth in Exhibit 11, Wildlife Information. To supplement data collected from the grids, a 24 station trap transect was located adjacent to each of five browse transects. These transects were trapped for three consecutive nights, each spring and in the fall through the spring of 1976. The transects were designed only to give supplemental data on species diversity and relative abundance within the various habitat types. No absolute numbers or abundance were generated; only an indication of abundance was derived. In addition, 24-station trap transects were located in habitat improvement areas two and three. As with the other transects, these were trapped for three consecutive nights in the spring of 1976. These transects were conducted to collect data on small mammal response to the removal of cover in the habitat improvement areas. The rodent trapping grids were sampled during the fall of 1975 and spring of 1976. For the fall of 1975, grid 1 (in sage-grass habitat type) averaged 36.7 rodents/acre, 99% of which. were deer mice. Grid 2 (in sage grass -serviceberry habitat type) was in poor condition (shrubs were sprayed in the past to improve grazing) and produced an average of 25 rodents per acre. on grid 2, 96+% of the rodents captured were deer mice. During the spring of 1976, grid 1 produced an average of 25.4 rodents/acre, and grid 2 produced an average of 20 rodents/acre. Trapping success for grids 1 and 2 were 30% and 23%, respectively. Total numbers of rodents captured and density per acre were higher in the fall than in the spring. This is a function of post-reproduction versus pre-reproduction numbers. Data from the trapping transects located adjacent to the browse transects was collected only to determine rodent species diversity within the habitat types. Table 2.04.11-9, Rodent Species/Habitat Type, shows the habitat types and the species captured. The U.S. Fish and Wildlife Service also conducted a nine day small mammal sampling program in 1915. Five traps were used on a 5-acre grid in a mark-recapture effort for six days. After the 6th day, a transect line (20 stations, 3 traps per station) was used to sample the area for three days and nights. Results of the small mammal sampling are shown in Table 2.04.11-10, USFWS - Small Mammal Transects. Additional information concerning the USFWS sampling program is found in Exhibit 11, Wildlife Information. Data collected for 1975 and 1976 show that, (1) rodent densities on the site were high compared to those of other areas of the west; (2) total numbers of rodents were affected by condition of the habitat; (3) Rule 2 Permits 2.04.11-6 Revision Date: 6/23/08 Revision No.: MR-91