4.4.8

management tactics include eXpanding highway structures across pr�existing drainages to facilitate wildlife
movement and tunneling through ridges instead of making cuts (Ruediger 2000). To effectively implement
these techniques, coordination between experts on these techniques and NPS would be necessary to
determine the best location and rype of structures.
Mitigation Technigues
GSMNP is committed to mitigation of impacts that can not be avoided or minimized, as part of its ongoing
Park policies. It will not be possible to avoid and/or minimize all impacts to black bears or their habitat by
the selection of a partial-build ar build alternative. Mitigation of impacts that cannot be avoided ar
minimized may include funding for habitat restoration and enhancement within GSMNP; however, the sites
where mitigation could occur are limited.
4.4.7.3 Impairment Evaluation
Impairment (as defined by NPS policy) of black bears in GSMNP and along the AT would not occur under
the No-Action Alternative, Monetary Settlement Alternative, Laurel Branch Picnic Area, and the Partial-
Build Alternative to Bushnell. The Northern Shore Corridor is not likely to impair black bears in GSMNP or
along the AT based on the information obtained to date. Due to the magnitude of this alternative, it is likely
that additional NEPA documentation would be required to address sit�specific impacts not currently known,
to determine detailed avoidance, minimization, and mitigation measures as they relate to final design, and to
re-evaluate the impairment determination related to black bears.
4.4.8 Migratory Birds
4.4.8.1 Methodology for Assessing Impacts
Migratory bird species that winter and breed in the project study area are critical components of ecosystems
within GSMNP. Assessment of impacts to migratory birds and their habitats is required by law prior to any
action, as directed by Executive Order 13186 and the Migratory Bird Treaty Act (MBTA). Secondly, these
impacts are outlined due to the importance of migratory birds to biodiversiry, ecosystem functions and to
human monitoring of environmental conditions. Impacts of each of the alternatives on migratory birds were
assessed using current, scientific literature regarding impacts of human activity on migratory birds and bird
habitats and consultation with experts in the field of avian ecology. Additional details are provided in
Appendix N.
Type
Type describes whether a possible impact would benefit (be beneficial to) or harm (be adverse to) migratory
bird populations.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-224
North Shore Road Final Environmental Impact Statement

Context
The context of an irr�pact can be sit�specific, local, or regional. Sit�specific is defined as the area within
the construction footprint; local as the area within 2 mi (3.2 km) of the construction footprint or the northern
shore of Fontana Lake (whichever is less); and regional as the area bounded by the northern shore of Fontana
Lake, the North CarolinalTennessee state line, Twenrymile Ridge to the west, and Noland Creek to the east.
Duration
Short-term impacts are those that would occur for less than 1 year, typically as an episodic or temporary
event. Long-term effects occur as a result of construction activities at a specific location throughout the life
of construction (this is assumed to be between 1 year and 15 years), but the impact is more than that of a
temporary event. Permanent impacts are considered to be anything that persists throughout the construction
period.
Intensity
Intensity is the degree to which resources would be affected and is categorized as no/negligible, minor,
moderate, or major. The intensity definitions for migratory birds were based on consideration of a wide
range of factors including the diversity of species included in this topic, the breadth of breeding area
requirements, direct loss of habitat and indirect modifications to the remaining bisected habitat, avoidance
behaviors due to noise and traffic, nest predation, and changes to the habitat quality.
NTMBs discussed in this section utilize different habitats and have different breeding territory sizes based
upon species-specific breeding behavior, interspecific competition, and various factars related to habitat
quality. Roads and other facilities can modify the surrounding foraging habitat making it less suitable for
invertebrates in leaf litter, a main source of food for some birds (Haske112000). Changes in animal behavior
have been noted in areas adjoining roads. Human disturbance and road noise can lead to animal avoidance
behavior (Clevenger and Waltho 2000; Trombulak and Frissel 2000). In woodlands, the density of birds can
be reduced up to several hundred meters away from roads and it is assumed that noise (Reijnen et al. 1987)
or reduced food supply (Ortega and Capen 1999) are the causes of this avoidance distance. Potential habitat
modifications considered include factors such as potential changes in the introduction of invasive exotic
species which can lead to changes in forest habitat and nest predation/competition.
The following intensity definitions apply to migratory birds found within or adjacent to the construction
footprint of the proposed project. The construction footprint includes the proposed area of pavement, the
adjoining cut and fill slopes, and the surrounding construction access buffer. There is no scientific literature
available that provides a scale to define or rank the severity of impacts from a project. Therefore, the
following intensity definitions are based on best professional judgment of what is reasonable considering the
complex interactions of the factors noted.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-225
North Shore Road Final Environmental Impact Statement

No/Negligible
The project impacts would affect less than 25 ac (l0 ha) of migratory bird habitat.
Minor
The project would impact between 25 ac (10 ha) and 100 ac (40.5 ha) of migratory bird habitat.
Moderate
The project would impact between l 00 ac (40.5 ha) and 200 ac (81 ha) of migratory bird habitat.
Major
The project would impact more than 200 ac (81 ha) of migratory bird habitat.
4.4.8.2 Summary of Impacts
Construction alternatives involving a construction footprint may negatively affect migratory birds via three
mechanisms: habitat loss, habitat fragmentation/edge effect, and noise. However, the respective magnitudes
of these effects would vary with the size of any construction footprint. For all alternatives that would
involve construction, those with larger construction footprints would likely result in greater negative effects
to migratory birds. There are also secondary impacts such as invasion of exotic species. These impacts are
summarized in this section and described in more detail in Appendix N.
Habitat Loss
Habitat loss is a leading cause of migratory bird declines (Askins et al. 1990; Robbins et al. 1989). In the
project study corridors, forest-dwelling bird habitat loss would occur due to deforestation in the construction
footprint if any partial-build or build alternative were selected. These activities would decrease the available
nesting and foraging habitat for breeding birds, as well as species that winter in the project study area.
Studies have shown the interiar farest-dwelling birds are lower in relative abundance adjacent to roads where
as edge-dwelling birds have higher relative abundance adjacent to roads (Ortega and Capen 2002; Ortega
and Capen 1999; Rich et al. 1994).
Habitat Fragmentation and Edge Effect
Migratory birds not only suffer from direct losses in habitat, but also from the negative impacts of this
habitat loss on the qualiry of remaining patches of habitat in the landscape. As small parcels of habitat are
removed from the perimeter and/or the interior portions of once larger habitat patches, many habitat edges
are formed throughout the landscape. In fact, the type and position of a newly created edge in a habitat patch
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-226
North Shore Road Final Environmental Impact Statement

can produce a variety of results in terms of amount of remaining habitat and amount of edge. Specifically,
creating habitat edges can pose a suite of detrimental impacts to migratory birds, especially interior forest-
dwelling species. These impacts include increased nest predation (Wilcove 1985; Forsyth and Smith 1973),
increased nest parasitism (Brittingham and Temple 1983), possible changes in vegetation structure and
increased competition with species that prefer mare fragmented habitats (Zannette et al. 2000; Askins et al.
1990). Forest-dwelling birds forced to nest nearer edges are more prone to nest failure due to predation.
Boulet and Darveau (2000) found that nest predation along forest edges resulting from roads was greater
than edges caused by logging roads, rivers or lakes.
Habitat edges resulting from roads attract nest parasites such as the brown-headed cowbird (Molothrus ater).
Brown-headed cowbirds are known for their especially high success in parasitizing migratory bird nests
(Askins et al. ] 990; Brittingham and Temple 1983) and decreasing these species' reproductive success rates
(Brittingham and Temple 1983). In fact, brown-headed cowbirds have been found to invade not only habitat
edges, but even the narrowest of corridors resulting from roads, especially when mowed grass is present
(Rich et al. 1994). The partial-build and build alternatives would increase the amount of edge habitat near
forest openings, and may thereby attract brown-headed cowbirds to these previously interior forest openings.
Cowbirds have been found to infiltrate several hundred meters into farests to parasitize migratory bird nests
(Brittingham and Temple 1983). As a result, cowbirds may not only negatively impact the nesting migratory
birds adjacent to the construction footprint and newly accessible forest openings, but also those breeding in
forests well outside the construction footprint. However, in heavily forested landscapes similar to the project
study corridors several studies have found no increase on nest predation (Ortega and Capen 2002; Hartley
and Hunter l 998).
When edges are created within forests, forest interior migratory birds are forced to compete with many edge-
dwelling species that tend to be more aggressive. 1'hese species may outcompete forest-dwelling migratory
birds for food (Zannette et al. 2000). Construction may also lead to outbreaks in exotic plant populations
(Forman and Hersperger 1996; Trombulak and Frisse12000). When native plant communities are replaced
with assemblages of invasive, exotic plant species, it is often accompanied by a decrease in insect
abundance, and thus less valuable forage for breeding migratory birds. (See Section 4.4.9 for more
information on the impacts of invasive exotic species.)
Noise
Studies have shown that car traffic and not the presence of a road is the main cause of decreased bird
breeding activity near roads (Rheindt 2003; Reijnen et al. 1995; Reijnen and Foppen 1994; Ferris ] 979).
Therefore, noise is the likely cause of disturbance to migratory bird populations (Forman and Hersperger
1996) by disrupting vocal communication required for mate selection, mate location, foraging
communication, predator detection and avoidance, and parent-nestling/fledgling communications. Wintering
birds may be affected in terms of foraging and predator location/avoidance. Soundscape impacts are
discussed in Section 4.3.5.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-227
North Shore Road Final Environmental Impact Statement

4.4.8.2.1 No-Action
The No-Action Altemative would involve no construction or alteration to the natural environment. For this
reason, no impacts to migratory birds or their habitats would be expected.
4.4.8.2.2 Monetary Settlement
The Monetary Settlement Alternative would not impact migratory birds within GSMNP.
4.4.8.2.3 Laurel Branch Picnic Area
This alternative would have the smallest construction footprint which would be approximately 9.0 ac (3.6
ha). Impacts to migratory birds via habitat loss due to construction are considered adverse, negligible, sit�
specific, and permanent. Adverse, negligible, local, and permanent impacts were characterized for habitat
fragmentation and facility-related soundscape impacts.
4.4.8.2.4 Partial-Build Alternative to Bushnell (Primitive and Principal Park Roads)
Possible impacts for this alternative include migratory bird habitat loss, habitat fragmentation, and noise
disturbance. Impacts due to direct habitat loss would be adverse, minor, site-specific, and permanent.
Indirect impacts of habitat fragmentation and noise intrusion would be adverse, minor, local and permanent.
These estimated impacts do not differ between the Principal Park Road and Primitive Park Road. The
Primitive Park Road would result in a construction footprint of approximately 99.4 ac (40.2 ha). Tbe
construction footprint resulting from the Principal Park Road would be approximately 7.0 ac (2.8 ha)
smaller. This reduction in acreage could result in decreased noise and habitat fragmentation.
Southern Option at Forney Creek Embayment (Primitive and Principal Park Roads)
This option, using the Primitive Park Road, would impact approximately 9.5 fewer ac (3.8 ha) than the
baseline Partial-Build Alternative to Bushnell. The Principal Park Road of this option would impact
approximately 15.6 fewer ac (63 ha) than the baseline Partial-Build Alternative to Bushnell. With either
road type, less noise and habitat fragmentation would result from using the Southern Option at Forney Creek
Embayment.
4.4.8.2.5 Northern Shore Corridor (Primitive and Principal Park Roads)
The Primitive Park Road would impact approximately 400.6 ac (162.2 ha) of migratory bird habitat within
the construction footprint. The Principal Park Road would impact approximately 8.4 fewer ac (3.4 ha) of
habitat. Impacts do not differ between the Primitive and Principal Park Roads in type, context, duration, or
intensiry. Potential impacts due to habitat loss would be adverse, major, sit�specific, and permanent.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-228
North Shore Road Final Environmental Impact Statement

Indirect impacts from noise generated by construction activities and facility operations, habitat
fragmentation, and edge effects would be adverse, major, local, and permanent.
Southern Option at Forney Creek Embayment (Primitive and Principal Park Roads)
The construction footprint of the Primitive Park Road would impact 9.5 fewer ac (3.8 ha) of migratory bird
habitat than would the baseline Northern Shore Corridor. The Principal Park Road would impact
approximately l 5.9 fewer ac (6.4 ha) in comparison with the baseline Northern Shore Option. In either case,
the Northern Shore Corridor with Southem Option at Forney Creek Embayment would provide a small
decrease in the construction footprint, noise intrusion, and possible negative effects of habitat fragmentation
relative to the baseline Northern Shore Corridor.
Southern Option at Hazel Creek and Eagle Creek Embayments (Primitive and Principal Park Roads)
The construction footprint under this option for the Primitive Park Road would impact approximately 25.4
fewer ac (10.3 ha) of habitat than would the baseline Northern Shore Corridor. The Principal Park Road
would result in approximately a 37.1-ac (15.0-ha) reduction in the construction footprint. These options may
result in less noise intrusion and habitat fragmentation than with the baseline Northern Shore Corridor.
Southern Option Crossing Fontana Dam (Primitive and Principal PaNk Roads)
Construction of this option using the Primitive Park Road would impact approximately 20.7 fewer ac
(8.4 ha) of migratory bird habitat than the baseline Northern Shore Corridor. The Principal Park Road under
this option would affect approximately 21.2 fewer ac (8.6 ha) than the baseline Northern Shore Corridor. In
both options, decreases in noise and habitat fragmentation may accompany the smaller construction
footprint.
4.4.8.2.6 Cumulative Impacts
Migratory birds dominate the avifauna of the Great Smoky Mountains, making up 80 percent of the breeding
bird community (MacArthur 1972) and include the greatest area of relatively undisturbed forests in the
eastern U.S. (Davis 1993). However, migratory birds are currently displaying their steepest declines in the
southern Appalachians, where 42 percent of forest-breeding species are declining (Franzreb and Rosenberg
1997). The Great Smoky Mountains harbor "source" populations of many migratory species (Farnsworth
and Simmons 1999). Source populations are those that reproduce at rates which exceed the number of
deaths in a population of a species. Therefore, these populations may be seen as creating a surplus of
migratory birds that then may disperse outside the project study area and even beyond the Great Smoky
Mountains. For this region, detriment to populations of migratory birds in GSMNP may have impacts on
migratory bird abundance that could ripple outward into other regions of the eastern United States.
Furthermore, if such declines in migratory bird abundance take place, it could also lead to negative effects on
biodiversity and food web structures within and outside GSMNP.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-229
North Shore Road Final Environmental Impact Statement

Some of the projects listed in Section 4.1.2 have affected or have the potential to affect migratory birds in the
study area. In the past, areas of histarically forested landscapes have been reduced by commercial and
residential development. Ongoing and future projects (including NCDOT STIP projects, construction on the
Ravensford site, and the completion of Foothills Parkway) would also result in habitat loss and
fragmentation. Private development, although greatly limited in the study area due to the amount of
publicly-owned land, would also affect migratory bird habitat in the study area.
Possible cumulative effects from selection of the partial-build or build alternatives to migratory birds may
result in decreased local migratory bird abundance, decreased local biodiversity, altered food webs, and
possible contributory impacts on regional avifaunal diversity. When added to those projects it is possible that
the major impacts resulting from the Northern Shore Corridor could constitute cumulative impacts to the
migratory bird habitat in the region. These cumulative effects have occurred and will continue to occur in
the foreseeable future as a result of landscape modification. Mitigation to protect, enhance, and restore
sensitive habitats would minimize the potential cumulative effects on the region's migratory bird habitat.
4.4.8.3 Options to Address Potential Impacts
NPS would employ a sequence of avoiding adverse impacts to inigratory birds to the extent practicable,
minimizing impacts that could not be avoided, and compensating for unavoidable adverse impacts.
However, it will not be possible to avoid or mitigate for all impacts to migratory birds.
Avoidance Technigues
There are no avoidance techniques that would completely avoid impacts to migratory birds by selection of
the partial-build or build alternatives.
Minimization Techniques
Few methods are available for minimizing the negative impacts of possible construction. The direct threats
to migratory birds via habitat loss, habitat fragmentation, and noise may be reduced by reducing the size of a
construction footprint or the construction time span. Predation to bird nests may be reduced by minimizing
litter on construction sites and around tourist areas post-construction, if construction occurs. As construction
activities may provide habitat and foraging pathways for nest predators, reducing the amounts of refuse
associated with disturbed areas may reduce initial populations of these arganisms. This minimization
technique may be most effectively attempted via education.
Mitigation Techniques
GSMNP is committed to initigation of impacts as part of its ongoing Park policies; however, mitigation
opportunities for impacts to migratory bird within GSMNP are limited. Mitigation of impacts that cannot be
avoided ar minimized may include funding for habitat creation and restoration, rare species management,
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-230
North Shore Road Final Environmental Impact Statement

and the establishment of interpretive programs related to interactions between tbe natural environment and
development. Since opportunities within the Park to restore migratory bird habitat are limited, GSMNP will
seelc cooperative opportunities with established conservation trusts to restore fragmented landscapes adjacent
to the park boundaries.
4.4.8.4 Impairment Evaluation
Impairment (as defined by NPS policy) of migratory birds in GSMNP and along tbe AT would not occur
under the No-Action Alternative, Monetary Settlement Alternative, Laurel Branch Picnic Area, and the
Partial-Build Altemative to Bushnell. Tl�e Northern Shore Corridor is not likely to impair migratory birds in
GSMNP or along the AT based on the information obtained to date. Due to the magnitude of this
alternative, it is likely that additional NEPA documentation would be required to address site-specific
impacts not currently known, to determine detailed avoidance, minimization, and mitigation measures as
they relate to final design, and to r�evaluate the impairment determination related to migratory birds.
4.4.9 Invasive Exotics
4.4.9.1 Methodology for Assessing Impacts
Analysis of impacts by invasive exotics on floral and faunal communities within the project study corridars
utilizes the length of the road to determine potential impacts. Approximate length of impact was calculated
using ArcGIS. Impacts were also assessed based on known locations of invasive exotic species occurring
within the proposed construction footprints. These known locations are based on data provided by GSMNP,
INHS, and 2004 field surveys. (See Section 3.�.9.1 and Appendix N for more information on these surveys.)
Type
Impact rypes are either beneficial or adverse. Beneficial impacts would have a positive effect to existing
floral and faunal communities. Adverse impacts would have a negative effect on existing floral and faunal
communities.
Duration
Short-term impacts are those that would occur for less than 1 year, typically as an episodic or temporary
event. Long-term effects occur as a result of construction activities at a specific location throughout the life
of construction (this is assumed to be between 1 year and 15 years), but the impact is more than that of a
temporary event. Permanent impacts are considered to be anything that persists throughout the construction
period.
Clarification of the term "baseline" for this project:
The Partial-Build Alternative to Bushnell and the Northern Shore Corridor include a baseline route, as well as options to that route.
Baseline routes and options are detailed in Section 2.5 and shown on Figure 2-8. Baseline routes have been compared to existing
conditions. Impact analyses for the options are shown as a difference from the associated baseline route.
Environmental Consequences — 4-231
North Shore Road Final Environmental Impact Statement