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Data on Environmental Variables.—Environmental data were taken on three different
<br /> forms. "General Description of Study Site" (one per site) organized data on each
<br /> weekly trapping period, data that apply to all six transects run during a particular week.
<br /> All study localities were plotted and labeled on the USGS County Series topographic
<br /> map, 'Boulder County, 1:50,000," on file with the senior author. "General Description of
<br /> Study Site" included the following data: name of study site (per Open Space tract
<br /> maps), location to 114 1/4 section (i. e., 40-acre parcel), elevation, USGS quadrangle,
<br /> directions for access; weather, day by day; general description of area, specifically
<br /> topography and drainage, general character of vegetation, degree and kind of
<br /> disturbance, and apparent threats of future disturbance.
<br /> One copy of the form, "General Description of Transect,"was completed for each 50-
<br /> trap transect; thus, a set of six such forms described and documented each weekly
<br /> study site. The purpose of this form was to record general information pertinent to all I
<br /> trap stations on a transect. The location of each transect was plotted and labeled (by
<br /> letter) on the appropriate USGS 7.5 minute quadrangle (1:24,000), on file with the
<br /> senior author. General description of each transect noted the name of the study site
<br /> and the letter (A through F) of the particular transect. Location of the transect relative to
<br /> other transects and or prominent landmarks on study site were noted to allow relocation
<br /> of the particular transect. Topography and drainage, topographic position, (ridge, upper
<br /> slope, mid-slope, lower slope, terrace, bottom, etc.), percent slope and aspect were
<br /> noted. Position in the riparian system (at confluence, or distance above or below,
<br /> meander, etc.) was described and the general appearance of the riparian system (total
<br /> length of continuous riparian vegetation, width of riparian system, etc.) was noted.
<br /> General description of vegetation included broad characterization of habitat, including
<br /> predominant forbs, grasses, shrubs, etc.). Disturbance and threats of disturbance were I
<br /> described at the level of the transect.
<br /> After experience at two study sites (Tracy Collins and VanVleet), data gathering by
<br /> station on each transect was restricted to even-numbered stations, to cut to a
<br /> reasonable amount the field time devoted to this purpose. Data per station were taken j
<br /> within a 1-m square PVC plastic frame situated with the trap at the center. A meter stick f
<br /> was dropped at random within the 1-m square. At each decimeter (10 cm) along the
<br /> meter stick, vegetation was scored in a matrix (by a simple check-mark or specific l
<br /> identification) as: bare ground, litter, grass, forb, shrub, or tree. In addition, for each 1-
<br /> m 2 trap station the following were recorded: maximum height of vegetation; distance I
<br /> from trap to the nearest shrub; distance from trap to the nearest tree; foliage diversity I
<br /> (number of hits or intersections by foliage of a vertical 2-m PVC pole held at the I
<br /> trapsite), and distance to water (standing or flowing). Further, the degree of light
<br /> exposure was noted as 'open," partial shade, or full shade (scored as 0, 1, and 2,
<br /> respectively) and soil was noted as clay, loam, or sand (scored as 1, 2, or 3,
<br /> respectively). A field for comments was included to allow general observations,
<br /> including clarification of entries elsewhere on the form.
<br /> Captures of small mammals were recorded on standardized data sheets that included
<br /> the following information: study site, transect, day (day 1, 2, 3 or 4 of work on that study I
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