Alternative Energy Draft EA - NASA Visitor Center at Wallops Flight ...

Environmental Consequences
of magnitude) simply because their height (typically 150 meters [500 feet] and taller) is within
the preferred zone of migration, their guy wires create additional collision hazards and steadyburning
lights serve as an attractant (Kerlinger et al., 2009, in review).
The level of mortality documented for the WFF site is somewhat higher than the mortality rate
reported at other wind projects. The number of fatalities for the WFF 2008–2009 avian study was
conservatively estimated to be 28 fatalities per year at the guyed North Boresight Tower and 44
to 68 fatalities at the unguyed South Meteorological Tower. In a review of data from 30 wind
farms in North America, Kerlinger et al. (2009) reported a rate of approximately seven carcasses
per turbine per year for the eastern United States. These data aren’t entirely comparable to WFF
given differences in calculation of mortality rate (Kerlinger et al.’s rates are corrected for
scavenging and searcher efficiency; a conservative factor of four was used to determine fatality
rate in the WFF avian study). The lack of multi-bird fatality events (greater than three carcasses
per tower on a single evening) in the WFF avian study is, however, comparable to the data
reported by Kerlinger et al. (2009). Unlike communication towers for which a number of largescale
multi-bird mortality events have been documented, multi-bird mortality events at a single
wind turbine are rarely observed (four times in approximately 25,000 turbine searches at 30 wind
farms) (Kerlinger et al., 2009). These findings from Kerlinger et al.’s (2009) data review, in
combination with the WFF avian study findings, suggest that the probability of large scale
mortality events occurring at the WFF project would be low. So while there may be mortality at
the individual level for a variety of birds, there is sufficient evidence to conclude that population
level effects are very unlikely.
The mortality study component indicates that risk for collision with the proposed turbines is
based on each species’ population status. That is, risk may be highest for abundant and common
species and lowest for State or federally listed avian species. Most of the species of carcasses
recovered in the avian study are categorized by CNWR (USGS, 2006) as abundant or common
during most seasons of the year (migratory species may be “uncommon,” “occasional,” or “rare”
during some seasons. Abundant species are defined as “very numerous” and common species are
“likely to be seen or heard in suitable habitat.” Only one species (Marsh Wren – uncommon) was
categorized as uncommon, occasional, rare, or accidental.
NASA has been monitoring the post-construction wildlife studies that have been conducted by
the New Jersey Audubon Society at the Jersey Atlantic Wind, LLC/Atlantic County Utilities
Authority (ACUA) five-turbine project in Atlantic City, NJ (Photograph 5). This facility was
built in 2005 and post-construction monitoring of impacts on birds has been ongoing since
August 2007. The Atlantic Ocean coastal setting is similar to the Wallops Island environment
and supports similar avian species composition. These similarities provide an opportunity to
determine the type of impacts that might occur at the proposed WFF project site.
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