January, 27, 2007
By Joe Kosack
Wildlife Conservation Education Specialist
Harrisburg, PA - The Pennsylvania Game Commission is partnering with the
National Aviary, Carnegie Museum of Natural History and Lafayette College
to evaluate how eastern golden eagles migrate through Pennsylvania, and
identify areas of potential conflict that migrating eagles face from the
developing wind energy program in the Commonwealth.
The possible increase of wind power on Appalachian ridges may threaten
golden eagles as they travel their historic migratory corridor that follows
these mountains through Pennsylvania to reach their nesting grounds in
eastern Canada or wintering grounds in the southern reaches of the mountain
chain. Since all known eastern golden eagle migratory routes track over the
Appalachian Mountains, possibly along or in close proximity to ridges
targeted for wind power development, the Game Commission must ensure the
well-being of this state and federally-protected species - as well as other
wildlife - as this growing industry sites turbines between the state's
Allegheny Front and Blue or Kittatinny Ridge.
For more than two decades, the eastern golden eagle has been recognized as
a geographically and genetically isolated population. That influenced its
ranking as a "Pennsylvania vulnerable" species in the state Wildlife Action
Plan adopted by the Game Commission and ratified by the U.S. Fish &
Wildlife Service in 2006. It is not, however, a state or
federally-endangered species.
"The recent increase in wind energy development projects in Pennsylvania
has raised several important wildlife conservation concerns, one of which
is the potential impacts to raptors which would be further pronounced
during their migrations through Pennsylvania," explained Bill Capouillez,
Game Commission Bureau of Wildlife Habitat Management director. "This
initiative will help address that immediate concern and in conjunction with
the Commission's efforts through a voluntary cooperative agreement with
wind energy developers, we hope to address the remaining issues related to
potential wildlife impacts. Turbine locations should ultimately be the
product of a thorough wildlife impact analysis, of which migrations of
golden eagles is only one part that needs to be taken into consideration."
"The Game Commission does not oppose harnessing wind power as an
alternative energy source. It offers substantial environmental benefits
over burning fossil fuels, reducing America's dependency on foreign oil,
and hopefully making electricity more affordable for Pennsylvanians. We
recognize that harnessing wind power is part of this state's and America's
future. It is the world's fastest-growing energy industry. Nonetheless, the
agency must ascertain what risks - both local and national - to wildlife
that instate wind turbines pose, especially since impacts have been
documented instate and elsewhere. It is our constitutional responsibility
and a matter of public trust to safeguard wildlife."
This golden eagle study will mark the second research project sanctioned by
the Game Commission to analyze the potential impact wind turbines create
for some wildlife species. The first was started in 2006 when the Board of
Game Commissioners approved a $153,000 State Wildlife Grant project to
monitor the pre-construction and post-construction mortality of bats and
birds at the proposed Penobscot Mountain Wind Farm in Luzerne County. A
planned 36-turbine wind farm on the Pocono Plateau presented the
opportunity to develop much needed pre-construction protocols and
assessments of bat activity, measure site-specific changes in bat activity
caused by wind farm development, and to correlate biological and
environmental variables to the wildlife impacts.
The $25,000 State Wildlife Grant subsidizes the $177,989 eastern golden
eagle telemetry study, largely funded by the National Aviary and Carnegie
Museum of Natural History. Officially titled, "Assessing conservation needs
of eastern golden eagles in Pennsylvania," the study will be headed by Dr.
Todd Katzner, the National Aviary's director of conservation and field
research. The project will chart the migration patterns of eastern golden
eagles using transmitters attached to free-flying eagles - as well as
individuals counting migrating eagles on ridge-tops. Researchers will trap,
fit and release golden eagles with a 70-gram, solar-powered transmitter
that will record their movements through GPS technology and send the
information to a satellite that will, in turn, route the information to
researchers.
"Using the Argos satellite system, these transmitters, once fitted on an
eagle's back, will send 10 to 15 GPS locations daily," explained Katzner.
"The data will be used to generate maps showing the specific route eagles
take as they migrate through Pennsylvania. In addition, we'll synthesize
data and observations to further understanding of eagle habitat use along
migration routes."
The study also will be used to corroborate whether eagle flight behavior is
influenced by changes in land topography and weather patterns.
"We're trying to get a better handle on how flight elevations and routes
used by migrating eagles are influenced by topography and meteorology,"
Katzner said. "The information is crucial to understanding the correlation
of eagle movements, landscape features and weather, and should help us
determine if differently constructed wind turbines expose eagles to greater
risk or provide increased protection. We are currently operating in an
information void."
This past November, two golden eagles were captured near Central City and
fitted with transmitters to verify the feasibility of this telemetry
project. To date, the birds have been transmitting signals and their
movements can be viewed at www.aviary.org/csrv/eaglePA.php. Under the SWG
project up to four more eastern golden eagles will be equipped with
backpack transmitters to provide movement information.
Field observations indicate that golden eagles migrating north to nesting
areas in spring remain between the Allegheny Front and Kittatinny Ridge as
they pass through the Commonwealth. "Their biannual passage through this
30- to 60-mile corridor provides Pennsylvania a chance to play a leading
role ensuring the future eastern golden eagles," Katzner said. "We must
determine if threats to their preferred habitat in this corridor will
impact the population's stability in any way. This Pennsylvania pass
creates a bottleneck for the population to pass through en route to
breeding and wintering grounds, where the population is more broadly
dispersed."
Golden eagles, which are found in mountainous areas throughout the world,
are mostly seen instate during their spring and fall migrations. About the
same size as a bald eagle, and sporting a wingspan that can exceed seven
feet, they soar more than they flap while flying, and lack the distinctive
white head that defines a mature bald eagle. Golden eagles primarily prey
on medium-sized mammals.
Golden eagles are identified in Pennsylvania's new Wildlife Action Plan as
a species that may be threatened by the development of ridge-top wind
turbine farms or clusters. "Careful attention should be made to proper
siting of turbines away from major migration pathways to minimize the risks
of collision," the Plan noted. "Thorough pre- and post-construction studies
are necessary to document the effect of wind turbines on golden eagles and
other migrating raptors."
Dan Brauning, Game Commission Wildlife Diversity Section supervisor, said,
"The National Aviary's and Carnegie Museum of Natural History's
contributions to this project have created a unique opportunity to explore
a relatively uncharted conservation concern. Help from two other
long-standing conservation partners, Penn State University and Hawk
Mountain Sanctuary, will round out this research effort. The Game
Commission, the state's growing wind energy industry and Pennsylvanians
surely will benefit from this research. But the biggest winners will be
golden eagles.
"What this all boils down to is Pennsylvania's ridge and valley province
plays an important role in the development of wind power and as a migratory
corridor for eastern golden eagles," explained Brauning. "That could mean
the future of this small population of eagles hinges on our ability to make
responsible and informed decisions concerning the development of wind farms
in this region," he noted. "But the project may also conclude there won't
be a problem for eagles. Right now, eastern golden eagle numbers are stable
or rising. We'd prefer to see them stay that way."
Created in 1895 as an independent state agency, the Game Commission is
responsible for conserving and managing all wild birds and mammals in the
Commonwealth, establishing hunting seasons and bag limits, enforcing
hunting and trapping laws, and managing habitat on the 1.4 million acres of
State Game Lands it has purchased over the years with hunting and furtaking
license dollars to safeguard wildlife habitat. The agency also conducts
numerous wildlife conservation programs for schools, civic organizations
and sportsmen's clubs.
The Game Commission does not receive any general state taxpayer dollars for
its annual operating budget. The agency is funded by license sales
revenues; the state's share of the federal Pittman-Robertson program, which
is an excise tax collected through the sale of sporting arms and
ammunition; and monies from the sale of oil, gas, coal, timber and minerals
derived from State Game Lands.
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