Appendix F Detailed Cover Type Tables - USDA Rural Development

Bemidji – Grand Rapids
Biological Assessment and Evaluation
Direct & Indirect Effects
Construction of transmission line infrastructure requires the permanent removal of trees within the
ROW. To reduce to potential of disruption of breeding activities, construction in appropriate blackthroated
blue warbler habitat would occur outside the breeding season.
Human activity along the chosen route will be high during construction when compared to nearby areas
of unfragmented habitat. This may prevent black‐throated blue warblers from using suitable habitat
along the ROW, especially if individuals have a low tolerance for humans.
Deforestation and fragmentation have increased the available habitat and range of the brown headed
cowbird in North America, bringing it into contact with species which have had little experience with
parasitism (Hilty et al., 2006). Forest clearing within the final ROW may increase suitable brown headed
cowbird habitat by creating grassland and brushy habitats, which may be used by this species. Brown
headed cowbirds are not specifically adapted to forested landscapes, parasitism is higher near forest
edges (Robinson, Thompson et al., 1995). Therefore, areas with a high edge‐to‐patch ratio would be
expected to be more susceptible to cowbird parasitism (Hilty et al., 2006). Black‐throated blue warblers
are known to be infrequently parasitized by brown‐headed cowbirds (Birds in Forested Landscapes,
2009), so local populations may be subjected to a slight increase in the risk of parasitism.
Route 1 Alternative (Great Lakes Pipeline)
No CNF, DRM, or DNR observations of black‐throated blue warblers have been made within one mile of
Route 1. No observations of this species were made along this route during the EP surveys. While no
observations have been made, appropriate forested habitat for this species likely exists in large enough
of an area to support breeding along this route. Where this route crosses appropriate forest habitat, it
would be converted to grasslands, likely reducing the amount of appropriate habitat for black‐throated
blue warblers in the Study Area. The width of the disturbed corridor would increase from 60 feet
(typical, existing) to 185 feet (existing plus Project ROW), thereby increasing the potential for brown
headed cowbird predation.
No nests are known to exist within the route. Impacts to individuals and appropriate habitat areas will
be minimized by applying BMPs to construction activities. If an active nest is found during construction,
potential impacts and avoidance will be assessed and coordinated with the appropriate agencies.
Route 2 Alternative (US 2)
No CNF, DRM, or DNR recorded observations of this species were made within one mile of this route,
nor was it observed during the EP surveys. While no observations have been made along this route,
appropriate forested habitat for this species likely exists in large enough of an area to support breeding.
Where this route crosses appropriate forest habitat, it would be converted to grasslands, likely reducing
the amount of appropriate habitat for black‐throated blue warblers in the Study Area. The width of the
disturbed corridor would increase from 580 feet (typical, existing) to 800 feet (existing plus Project
ROW), thereby increasing the potential for brown headed cowbird predation.
No nests are known to exist within the route. Impacts to individuals and appropriate habitat areas will
be minimized by applying BMPs to construction activities. If an active nest is found during construction,
potential impacts and avoidance will be assessed and coordinated with the appropriate agencies.
Route 3 Alternative (Northern Route)
No CNF, DRM or DNR observations of black‐throated blue warblers have been made in the Route 3
vicinity. No observations of this species were made along Route 3 during the BGR surveys. While no
observations are present, it is likely that appropriate habitat exists in large enough of an area to support
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