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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-57 In addition to intensity, duration was evaluated in terms of short-term and long-term impacts. Impacts are considered short-term if they disturb vegetation or wildlife, but do not prevent the reestablishment of vegetation and wildlife communities to pre-impact structure and functionality within five years. Impacts to grasslands are frequently considered short-term because these communities typically recover more quickly than plant communities possessing a woody component (Olson et al. 2000; Lesica et al. 2005). Long-term impacts continue for an extended period of years. Due to their woody component, long-term impacts can be expected in sagebrush dominated areas. Another example of short-term versus long-term impact would be collision risk with construction vehicles—which would be a short-term impact in most cases (assuming population levels recover within a few years) versus the long-term impact of collision risk with the conductor lines—with the risk continuing for the duration of the Project. The main impacts to Sage-Grouse that could occur from construction, operation, and maintenance of the proposed Project include: 1) Habitat loss and degradation, including direct habitat loss at structures and access roads and indirect habitat loss or degradation in the surrounding landscape resulting from spread of invasive exotic weeds and fires. 2) Potential predation opportunities from avian and terrestrial predators; primarily from avian predators using the transmission structures as perches and nesting substrates. 3) Potential behavioral avoidance of infrastructure associated with the proposed Project. 4) Disturbance and displacement from temporary human presence during construction and maintenance activities. 5) Impairment of habitat connectivity between Sage-Grouse populations in Washington. 6) Direct mortality to Sage-Grouse through collisions with the transmission line conductor and structures, destruction of Sage-Grouse nests during construction, and collisions with construction and maintenance vehicles. Biological Disturbance Many species are sensitive to disturbance by the presence of humans, which can occur through construction activities and road access. Increased disturbance can result in reductions in productivity, increases in energy expenditures, or displacements in population (Bennett 1991; Mader 1984); however, the magnitude of impact to the species often depends on the specific disturbance. Examples of disturbance from transmission line presence are collision risk, and avoidance behavior. Disturbance from access roads includes human disturbance of breeding areas, nests, dens, and burrows. Potential disturbance to wildlife species associated with the proposed Project includes any activities, either short- or long-term, that would disrupt species. The increased stress on wildlife caused by the disturbance may result in decreased productivity (e.g., failed or abandoned nest), decreased survival (e.g., collision), or displacement (e.g., abandonment of previously occupied areas). The wildlife species that occur in different vegetation communities are described in Section 3.3 - Wildlife and Special Status Wildlife Species and Tables 3.3-3 and 3.3-7. Disruption from the proposed Project was analyzed by taking into account: 1) increased noise levels during construction; 2) increased noise levels from the energized transmission line; 3) increased vehicle traffic during construction and maintenance activities; 4) increased off-highway vehicle use and other recreational traffic because of increased access; and 5) the presence of structures and conductors (collision risk and perching opportunities).