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Potential Mexican Spotted Owl Habitat and Use for the Hitch Rack Ranch Project <br /> steeper slopes indicate exposed rock outcrop formations that typically are present in MSO habitat within <br /> Colorado. <br /> Step 4—Assembly of Conifer Vegetation Coverage <br /> Mixed conifer is considered to be an important vegetation characteristic of MSO habitat in Colorado <br /> (Johnson 1997). Polygons of mixed conifer(i.e., Douglas-fir, white fir, ponderosa) stands were extracted <br /> from the Southwest ReGAP cover database for the study area. As an example, Figure 6 illustrates mixed <br /> conifer stands (identified as green-shaded areas) located along the prescribed drainage within the study <br /> area. <br /> Step 5— Identification of Perennial Streams <br /> MSO habitat in Colorado is located in narrow canyons, generally within 100 meters of a canyon bottom <br /> (i.e., streambed) (Johnson 1997). Consequently, perennial streams in the study area were used as an <br /> indirect method to locate canyon bottoms. GIS was then used to delineate a 100-meter(horizontal <br /> distance) buffer along either side of perennial streams, creating a 200-meter-wide corridor around <br /> streams. This corridor was used as a "spatial mask" (screening tool) in subsequent steps to preferentially <br /> identify narrow canyons. Figure 7 indicates the spatial mask along the sample area within the study area. <br /> Step 6—Screening Slope and Vegetation Using the 100-meter Spatial Mask <br /> Steep narrow canyons with mixed conifer provide breeding habitat(including nesting, roosting, and <br /> foraging habitat) and thermal cover for MSO in Colorado (Johnson 1997). In this step, slope (greater than <br /> 40 degrees) and mixed conifer attributes were combined into a single map and then clipped to include <br /> only those areas within 100 meters of perennial streams using the spatial mask. This process identifies <br /> and highlights the slope and vegetation patterns in narrow canyons only, excluding areas considered to <br /> be less suitable habitat for MSOs. Figure 8 shows a portion of the study area that has the appropriate <br /> slope, perennial stream, and vegetation characteristics. <br /> Step 7—Elevation Screening <br /> Breeding habitat(including nesting, roosting, and foraging habitat) for MSOs in Colorado occur at <br /> elevations between 6,500 and 8,500 feet amsl (Johnson 1997). Consequently, slope and mixed conifer <br /> maps were further clipped within the 100-meter mask to expose only the slope and mixed conifer patterns <br /> in narrow canyons between the elevations of 6,500 and 8,500 feet amsl. Figure 9 is an example of the <br /> potentially suitable MSO habitat identified by this modeling analysis. <br /> Step 8—Superimpose Potential Habitat on Topographic Maps <br /> Breeding habitat for MSOs in Colorado is characterized by a combination of attributes: steep slopes <br /> (greater than 40 degrees), narrow canyons, mixed conifer, and elevations between 6,500 and 8,500 feet <br /> amsl (Johnson 1997). The clipped 100-meter spatial mask area with slope and mixed conifer between <br /> 6,500 and 8,500 feet amsl was superimposed on a USA Topo Map to identify areas of potentially suitable <br /> habitat. Figure 10 illustrates an area of potentially suitable MSO breeding habitat superimposed upon a <br /> USA Topo Map. <br /> Step 9—Identify Potential Breeding Habitat <br /> Polygons of potential MSO breeding habitat were mapped on USA Topo Maps. Figure 11 identifies <br /> potentially suitable MSO breeding habitat in the study area. <br /> Results <br /> A total of six potential MSO breeding habitat areas, consisting of canyons or side drainages, were <br /> identified within the study area. These areas are presented in Table 1. The locations and extent of <br /> September 2017 4 <br />