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Preble's Meadow Jumping Mouse Habitat Assessment& Conservation Plan <br /> Two Rivers Parcels—Varra Companies <br /> Weld County, Colorado <br /> activity within areas determined to be potential Preble's habitat(generally stream and riparian habitats <br /> along the Colorado Front Range and southeastern Wyoming). Typically, Preble's occurs in low <br /> undergrowth consisting of grasses and forbs, open wet meadows, riparian corridors, or where tall <br /> shrubs and low trees provide adequate cover(Service 2004; Meaney and Clippinger 1995). Preble's <br /> occurs below 7,600 feet in elevation, generally in lowlands with medium to high moisture (Service 2004; <br /> Natural Heritage Program 1996) along permanent or intermittent streams (Ryon 1996). <br /> Trapping Methods <br /> Prior to conducting the 2017 field survey for Preble's, ERO remotely reviewed the survey area to <br /> determine the location and extent of any potential Preble's habitat. ERO biologists conducted a <br /> preliminary site visit in August 2017 to determine locations of suitable habitat within the survey area for <br /> setting traps. It was the intent of the entire survey to be overly inclusive in determining areas to be <br /> surveyed for the presence or absence of Preble's. <br /> ERO conducted the trapping survey using the methods outlined in the U.S. Fish and Wildlife Service's <br /> Preble's Meadow Jumping Mouse Survey Guidelines, revised April 2004(Service 2004). During the 2017 <br /> field survey, ERO placed live-traps beginning the afternoon of September 11 and collected traps on the <br /> morning of September 15, 2017. Trap points were placed approximately 10 meters apart along transect <br /> lines on the north and south sides of Little Thompson River and south side of the adjacent canal as well <br /> as the north side of the South Platte River. One trap was set at each point over a period of four nights. A <br /> total of 180 traps were checked each morning at sunrise, closed, and reopened each evening at dusk,for <br /> a total of 720 trap nights. Specific start and end locations of trap lines were determined based on <br /> availability of suitable habitat along the rivers and canal. The traps used were Sherman large folding and <br /> nonfolding aluminum and steel traps with galvanized treadles and doors. The traps were baited with <br /> Country Acres' Sweet Mix Plus (Omalene). <br /> All individuals captured were identified to genus and species, and age and sex were documented. <br /> Standard field procedures for small mammal trapping were used following the guidelines approved by <br /> the Animal Care and Use Committee of the American Society of Mammalogists (Sikes 2016). <br /> Survey Results <br /> Small mammal live-trapping was conducted over a period of four nights during September of 2017, <br /> resulting in a total of 720 trap nights. No Preble's were found during the 2017 field survey. Four <br /> different species of small mammals, with 177 individual mammals, were trapped on-site (Table 2). Deer <br /> mice (Peromyscus maniculatus)were the most common species trapped,followed by house mice (Mus <br /> musculus), meadow voles (Microtus pennsylvanicus), and prairie voles (Microtus ochrogaster). <br /> 5 <br /> ERO Resources Corporation <br />