Raptors and wind energy: methodology

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Raptors and wind energy
methodology
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First, a few facts about raptors

• raptors are wide-ranging, area- sensitive
  predators that, except for some vultures, tend
  to be widely spaced most of the year
• exceptions to this include during migration
  when large numbers of raptors concentrate along
  leading lines and diversion lines

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Schematics of leading lines and diversion lines
creating narrow-front migration
Leading-line migration concentration
Diversion-line migration concentration
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Now, a few facts about raptors in Pennsylvania

• the Kittatinny Ridge in eastern Pennsylvania is
  an important leading-line corridor that is
  regularly used by 16 species of raptors,
  including Bald Eagles, Golden Eagles, and
  Peregrine Falcons

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An example of concentrated movement along a
leading line
The Kittatinny Ridge
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The view to the east from Hawk Mountains North
Lookout along the 300-mile long leading line of
the Kittatinny Ridge
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A summary of the flightalong the Kittatinny

• 16 species of birds of prey are regular migrants
  on the ridge
• about 20,000 migrants are counted at individual
  watchsites along this leading line during
  outbound migration each autumn
• many of the migrants thermal soar and slope soar
  on the ridge while migrating
• slope soaring and gliding along the ridge is
  more common in October-December than earlier
  in the autumn
• slope soaring and gliding migrants often pass at
  tree-top level

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Autumn hawkwatching on the Kittatinny

• 80,000 people visit Hawk Mountain Sanctuary each
  autumn
• tens of thousands visit other watchsites along
  the Kittatinny in autumn
• most of these people come to see the wide-open
  vistas, colorful autumn leaves, and Pennsylvania
  countryside, as well as the migrating birds of
  prey

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(The Atlas of Pennsylvania, Temple Univ. Press,
1989)
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And now a couple of facts about Hawk Mountain
Sanctuary

• Hawk Mountain Sanctuary is the oldest and
  largest member-based raptor conservation
  organization in the world
• published our first paper on raptor migration
• in 1934
• visited our first wind-energy facility in 1995
• served as NAS representative on the avian
  subcommittee of the National Wind Coordinating
  Committee beginning in 1996

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A couple of facts about Hawk Mountain
Sanctuary cont

• member of the review team for Studying wind
  energy/bird interactions a guidance document
  published by NWCC in 1999
• published first global atlas of raptor
  migration in 2000
• published a summary of the ecology and
  conservation of migrating raptors in 2006

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At Hawk Mountain we know a few things about
raptors, particularly migrating raptors
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The RAPTOR WATCH directory has been used as a
reference for siting wind-energy facilities by

• conservationists in Bulgaria, Mexico, and the
  United States
• the wind-energy industry in Nicaragua
• the UN sponsored Convention on Migratory
  Species
• The World Bank

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Studies of wind power-bird interactions continue
to grow as the number of operational turbines
increases. Two major themes appear to be
emerging from these studies. First, older
turbines kill more raptors than newer turbines.
And second, regardless of the type of turbine,
improperly sited and inappropriately managed wind
farms can and almost certainly will cause
problems for raptors, including migratory
species. cont
Next, some facts about wind power and raptors
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Key factors in reducing the potential impact of
wind farms include (1) situating them away from
high-density raptor populations and known
migration corridors and bottlenecks, (2) avoiding
sites that will displace existing populations
from important nesting and feeding areas, and (3)
using on-off cycles to reduce the likelihood of
collisions during periods of peak raptor
migration (Percival 2005).
-- Bildstein 2006
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Finally, the methods used in assessing and
reducing wind power-raptor interactions

• pre-construction suitability
• assessment and screening (EIV)
• post-construction surveillance
• post-construction risk reduction,
• including land management,
• turbine stoppage, and turbine
• removal

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An example of concentrated movement along a
diversion line
Strait of Gibraltar
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The end of the diversion line A nine-mile
crossing to Morocco for more than 400,000 soaring
migrants
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A flock of migrating Griffon Vultures at the
Strait of Gibraltar
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(No Transcript)
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Some of the more than 700 wind turbines at the
site
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Some are in the flat lands peripheral to the
main flight
others are in more hilly areas along the main
flight line.
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Strait of Gibraltar
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Mortality approximated 0.03 raptors per turbine
annually in a wind-energy facility with 66
turbines, or one Griffon Vulture and one
Short-toed Snake Eagle killed in 14 months of
study.
De Lucas, et al. 2004. The effect of wind farms
on birds in a migration point the Strait of
Gibraltar. Biodivers. Conservation. 13395-407
The authors concluded that the wind-energy
facility in question was of low risk, most
likely because migrants in the area were
flying well above the height of the blades.
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Strait of Gibraltar
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Mortality approximated 0.12 vultures and 0.14
kestrels per turbine annually in two
wind-energy facilities with a total of 250
turbines, or 30 vultures and 36 kestrels killed
annually.
Barrios and Rodriguez. 2004. Behavioural and
environmental correlates of soaring-bird
mortality at on-shore wind turbines. J. Appl.
Ecol. 4172-81.
Because most of the collisions occurred at a
small number of turbines and during predictable
wind conditions, the authors recommended
suspending operations of specific turbines during
high-risk situations.
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Covering a cow carcass
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(No Transcript)
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Griffon Vulture
Griffon Vulture
Eurasian Kestrel
Black Kite
Short-toed Snake Eagle
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All of this leads us to conclude that the most
important methodological approach involved in
reducing the extent of raptor-wind turbine
interactions is the first one mentioned on the
very first page of the Executive Summary of the
National Wind Coordinating Committees 1999
Guidance Document
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To wit,produce a body of information
adequate to

• assess the suitability of a proposed wind plant
  site with regard to birds of concern
• assess the potential effects of a wind plant on
  birds of concern
• evaluate the potential effects of wind energy
  technology on birds

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The NWCC was formed in 1994 as a collaborative
endeavor composed of representatives from diverse
sectors including electric utilities and their
support organizations, state utility
commissions, state legislators, consumer
advocates, wind equipment suppliers and
developers, green power marketers, environmental
organizations, and state and federal agencies.
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Simply put, pre-construction evaluation is the
critical methodological approach, and
suitability assessment is the place to start.
We need to decide where in Pennsylvania it is
suitable to construct wind plants and where it is
not. Based on what we already know about the
Kittatinny Ridge and its migratory raptors, the
ridge is not a suitable site for wind plants.
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For more information on Hawk Mountains position
on raptors and wind power go to
www.hawkmountain.org raptor conservation
principles in raptor conservationWind
power and raptors their interactions and ways to
reduce them.
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Hawk Mountain Sanctuary founder Rosalie Barrow
Edge (1877-1962)
The time to save a species is while it is
still common.
-- Framing the birds of prey, Emergency
Conservation Committee, Pamphlet No. 5, 1929