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Potential Mexican Spotted Owl Habitat and Use for the Hitch Rack Ranch Project <br /> Although the Project area occurs within designated critical habitat for the MSO and occurs within <br /> important transitional habitat for wildlife, the Project occurs within a general area that has experienced <br /> significant residential growth over the last 25 years. Residential growth, among other activities <br /> (residences, buildings, and roads), have been identified as potential threats to the MSO (USFWS 1995). <br /> This development has likely resulted in both direct(surface disturbance) and indirect(increased noise <br /> and human presence, artificial lighting, etc.) effects that can contribute to reduced habitat quality and <br /> increased habitat fragmentation. Based on the location of the Project and existing disturbance in the <br /> Project vicinity, the Project would incrementally increase surface disturbance and habitat fragmentation <br /> effects to potential habitat used by transient, dispersing, and wintering MSOs. However, it is unlikely that <br /> the Project would result in adverse effects to the MSO. <br /> Relative to mine-related activities in relation to known breeding MSOs within the Project region, MSOs at <br /> a site located approximately 1.3 miles up canyon of an active rock quarry and approximately 1.9 miles <br /> west of another active rock quarry have produced young over multiple years dating back to the early <br /> 1990's. Interestingly, this site also experienced an extremely high level of site fidelity. In fact, a male MSO <br /> that was banded on site in 1994 was relocated at the same site during multiple years, most recently in <br /> 2016. Likewise, an active MSO site occurs along a popular County Road Scenic Byway through a major <br /> canyon system has been active with MSO pairs for decades. Studies suggest that spotted owls may show <br /> some level of habituation to human activities where noise and distance was measured (Delaney et al. <br /> 1999; Johnson and Reynolds 2002). Consequently, there may be a level of human-related activity that <br /> can be tolerated or habituated by MSOs. <br /> Summary <br /> Based on the habitat model that was produced for the Project, suitable breeding habitat may be a limiting <br /> factor for the MSO population within the Project region. As discussed above, no breeding habitat occurs <br /> within the Project area. The closest potential breeding habitat occurs approximate 0.4 miles west of the <br /> Project area. Project area use by MSOs, if it occurs, would be limited to roosting and foraging activities by <br /> transient, dispersing, and wintering individual MSOs, as evidenced by radio-telemetry data in the Project <br /> vicinity (Johnson 1997). <br /> Based on data between 1992 and 1996, MSOs have been tracked from their higher elevation breeding <br /> habitats consisting of narrow steep-walled rocky canyons dominated by mixed conifer forests, to lower <br /> elevation canyons or drainages with a north-to-south orientation during late fall, winter, and early spring, <br /> and return to their previous summer sites (Johnson 1997). Consequently, overall habitat quality for the <br /> MSO in Colorado could be associated with a combination of narrow, steep-walled rocky canyon with <br /> mixed conifer and shallower, less-defined canyons or drainages with a southern aspect at lower <br /> elevations for wintering (Johnson 1997). As suggested above, suitable breeding habitat appears to be a <br /> limiting factor to MSO population growth in the study area, while inter-seasonal habitat(e.g., winter <br /> habitat) appears to be more abundant. If this is the case, then the Project is unlikely to have an adverse <br /> effect on MSOs as the Project occurs in inter-seasonal habitat given the amount potential inter-seasonal <br /> habitat within the study area as compared to the amount of potential breeding habitat in the study area. <br /> Over the last 25 years, significant residential development along the U.S. Highway 115 corridor has <br /> resulted in increased habitat fragmentation and human presence, which has contributed to a reduction in <br /> overall habitat quality for wildlife, including MSOs in the study area. Based on the location of the Project <br /> area and level of existing disturbance through the development of residential communities and road <br /> systems, the Project would result in an incremental increase in the overall habitat fragmentation effects to <br /> the study area, particularly within winter and inter-seasonal habitats for the MSO. <br /> September 2017 6 <br />