Chapter 5 Threats
5.6 Transportation and Service Corridors
Threats associated with this category relate to roads, railroads, utility and service lines, shipping lanes, and flight paths, and to the vehicles that use them when conflict results in wildlife mortality (Salafsky et al . 2008) . Roads are significant features of most landscapes, covering about 1% of the United States and ecologically influencing an estimated 15-20% of the United States land area (Jochimsen et al. 2004) . Land-based transportation systems include highways and secondary road networks, logging and fire access roads, causeways and bridges, and railroads and rail yards. Utility and service corridors and rights-of-way include electrical and telephone lines, oil and gas pipelines, stormwater and sewer system lines. Coastal shipping lanes, intercoastal waterways (IWW), and canals for boat and ship transportation and utility lines are aquatic-oriented transportation and service corridors. Airport runways and flight paths between airports are another type of transportation corridor (Salafsky et al. 2008) . 5.6.1 Anticipated Impacts Potential impacts from transportation and service corridors on terrestrial wildlife species and their habitats are numerous. The characteristics of a road or service corridor will affect the degree to which it creates a barrier to species (Clark et al. 2010; Clevenger et al. 2003; Wiens 1997) . Corridors consist of impervious surfaces or vegetation that is mowed or otherwise maintained periodically. New corridors have the potential to convert diverse wildlife habitat (e.g., mixed hardwood forest) to habitats that support few or no species. Maintained corridors can also serve as pathways for the spread of invasive plant species. Habitat fragmentation is the most common impact to terrestrial environments, but there are other important impacts that can negatively impact wildlife (Clark et al. 2010; Forman and Alexander 1998) . The presence of roads increases the mortality of wildlife from vehicular collision, which can lead to changes in demographic and structural changes of populations (Clark et al. 2010; Mazerolle 2004; Row et al. 2007) . For small animals with limited dispersal capacity (e.g., some amphibians), roads and service corridors can create a barrier to gene flow, resulting ultimately in loss of diversity and decreased population fitness (Clark et al. 2010; Frankham et al. 2002) . The results of a study on the effects of roads on Timber Rattlesnakes demonstrated there was a significant effect on genetic structure and gene flow among populations (Clark et al. 2010) . Highways impact wildlife through avoidance, fragmentation, direct and indirect loss of habitat, and mortality (Ruediger 1996, 1998) . Conover et al. (1995) , extrapolating from a variety of sources across the United States, estimated 726,000 deer-vehicle collisions annually. Studies have also identified short-term negative impacts on Black Bears (Brody and Pelton 1989; Beringer et al. 1990) , Grizzly Bears (Mattson et al. 1987) , Gray Wolves (Paquet and Callaghan 1996) , and other carnivores (Gibeau and Heuer 1996) . NCWRC data indicate a minimum of 50 to 100 Black Bears are killed in central and northeastern North Carolina by automobiles yearly. Road mortality of amphibians and reptiles
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2025 NC Wildlife Action Plan
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