Effects of wind farms on raptors: A systematic review of the current knowledge and the potential solutions to mitigate negative impacts

Abstract

Wind farms are a clean and efficient source of renewable energy. However, they cause negative impacts on raptors. Here, we present a review of the existing scientific literature on the effects of wind farms on raptors' ecology with a particular interest in the potential solutions. After collecting 216 studies, we found a consensus in the literature that raptors exhibit avoidance behaviors, and that the abundance of raptors decreases after wind farm installation, although it might recover over time. The position of wind farms on mountaintop ridges poses a particular danger to large soaring raptors, as they rely on orographic uplift to gain altitude. Adult mortality significantly affects population dynamics, particularly in endangered species, but young inexperienced individuals show a higher collision risk. The combination of different methods including field monitoring, GPS telemetry and systematic search for carcasses is an adequate approach to further investigate the problem and solutions. Shutdowns on demand, the installation of deterrents, turbine micro‐sitting and the repowering of wind farms have been suggested as potential solutions, although results are contradictory and case‐specific. Furthermore, it is essential to report the potential occurrence of conflicts of interest in scientific papers, as they can influence the interpretation of the results. Finally, from a future perspective, it is crucial to assess the effectiveness of solutions to mitigate the negative effects of wind farms to promote raptor conservation. This becomes increasingly relevant in the context of renewable energy development and increasing energy demand worldwide.

Full text

REVIEW
Effects of wind farms on raptors: A systematic review of
the current knowledge and the potential solutions to
mitigate negative impacts
I. Estell
es-Domingo &P.L

opez-L
opez
Movement Ecology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, C/ Catedr
atico Jos
e Beltran 2,
Paterna, Valencia, 46980, Spain
Keywords
bird collisions; conservation; environmental
impact assessment; mitigation; renewable
energies; wind farm; wind energy; raptors.
Correspondence
Irene Estell
es-Domingo, Movement Ecology
Lab, Cavanilles Institute of Biodiversity and
Evolutionary Biology, University of Valencia,
C/ Catedratico Jose Beltran 2, Paterna,
Valencia, 46980, Spain.
Email: irene.estelles@uv.es
Editor: Iain Gordon
Associate Editor: Zhongqiu Li
Received 13 March 2024; accepted 23
August 2024
doi:10.1111/acv.12988
Abstract
Wind farms are a clean and efficient source of renewable energy. However, they
cause negative impacts on raptors. Here, we present a review of the existing scien-
tific literature on the effects of wind farms on raptors’ecology with a particular
interest in the potential solutions. After collecting 216 studies, we found a consen-
sus in the literature that raptors exhibit avoidance behaviors, and that the abun-
dance of raptors decreases after wind farm installation, although it might recover
over time. The position of wind farms on mountaintop ridges poses a particular
danger to large soaring raptors, as they rely on orographic uplift to gain altitude.
Adult mortality significantly affects population dynamics, particularly in endangered
species, but young inexperienced individuals show a higher collision risk. The
combination of different methods including field monitoring, GPS telemetry and
systematic search for carcasses is an adequate approach to further investigate the
problem and solutions. Shutdowns on demand, the installation of deterrents, turbine
micro-sitting and the repowering of wind farms have been suggested as potential
solutions, although results are contradictory and case-specific. Furthermore, it is
essential to report the potential occurrence of conflicts of interest in scientific
papers, as they can influence the interpretation of the results. Finally, from a future
perspective, it is crucial to assess the effectiveness of solutions to mitigate the neg-
ative effects of wind farms to promote raptor conservation. This becomes increas-
ingly relevant in the context of renewable energy development and increasing
energy demand worldwide.
Introduction
The development of renewable energies has constituted a
significant paradigm shift in addressing the escalating global
energy demand. Renewable energies offer an alternative
solution to fossil fuel energy sources and their polluting
emissions, which are increasingly contributing to climate
change (Sawin et al., 2018). Electric power generation
through wind energy stands out as the technology that has
experienced the most substantial global expansion in recent
decades, owing to its capacity for efficient and cost-
effective energy production without emissions (Kumar
et al., 2016). For this reason, it is perceived as a favorable
environmental alternative (Allison et al., 2017). However,
there is a growing concern regarding the negative impacts
that wind farms can generate on both biodiversity and the
landscape (e.g. Kunz et al., 2007; Smallwood &
Thelander, 2008; Bailey et al., 2010; Schuster, Bulling, &
Koeppel, 2015). Among these impacts, wildlife mortality
due to collision with turbine blades, habitat fragmentation,
habitat degradation and habitat loss, as well as mortality
resulting from collisions and electrocutions with associated
electrical transmission infrastructures in the form of power
lines (Drewitt & Langston, 2006) are prominent. The spe-
cies most directly affected by wind farms are birds and
bats, primarily due to their high vulnerability to collisions
(Osborn et al., 2000). Specifically, there is broad consensus
in the scientific literature that soaring birds, and particularly
raptors, are the most vulnerable avian group to wind farm
collisions (e.g. Hunt, 2002; Barrios & Rodriguez, 2004;
Drewitt & Langston, 2006; Madders & Whitfield, 2006;de
Lucas et al., 2008; Lanzone et al., 2012). This vulnerability
stems from the fact that even small mortality rates can have
severe effects on long-lived species that typically exhibit
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of Lon-
don. 1
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any
medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Animal Conservation. Print ISSN 1367-9430

low rates of reproduction and slow development, as is often
the case with raptors (Linder et al., 2022).
The vulnerability of raptors can vary depending on mor-
phology, home range behavior, flight type and habitat use
within their living environments (Dohm et al., 2019). Addi-
tionally, the degree of vulnerability also depends on the type
of technology used in wind farm construction, the arrange-
ment of wind turbines, rotor height and blade size (Ster
ze &
Pogacnik, 2008; McClure et al., 2021b). The habitat type in
which wind farms are situated, the prevailing weather condi-
tions and the local topography are also significant factors to
consider when assessing the risk of raptor collisions (Watson
et al., 2018). Although there is an extensive body of litera-
ture on the actual and potential impacts of wind farms on
raptors, the disparity in methodologies and technologies
employed for analyzing animal behavior in relation to wind
turbines results in substantial variation in study outcomes,
both within and among geographical regions (Sheppard
et al., 2015; Chabot & Slater, 2018). New remote tracking
technologies, notably GPS/GSM tracking, play a pivotal role
in the assessment of impacts (Kikuchi et al., 2019). How-
ever, there is substantial variation among device types and
data processing methods (L
opez-L
opez, 2016). Therefore,
despite the growing concern over the potential combined
impacts of all the previously mentioned factors on raptors,
there is a lack of consensus studies that synthesize the pri-
mary findings regarding the effects wind farms can have on
birds in general, and raptors in particular. This is because
most results from published works tend to be context-
dependent, influenced by the specific spatial and temporal
conditions in which they were conducted (Katzner
et al., 2019). This is primarily due to the variability in
behavioral responses among species, the types of environ-
ments studied, the technology used for tracking in each
country and the specific biogeographic region in which wind
farms are located (Watson et al., 2018; Dohm et al., 2019;
Battisti et al., 2020).
Amidst the backdrop of the rapidly increasing global
energy demand and the ongoing energy transition, it is cru-
cial to comprehend the effects of wind farms on the most
vulnerable species (Fernandez-Bellon et al., 2019). Since
raptors constitute a diverse group of species and many of
them are conservation flagship species, their protection can
benefit numerous other species, serving as umbrella species
(Bose et al., 2020). The pursuit of global solutions and,
above all, the verification of the effectiveness of these solu-
tions are fundamental in reducing and reversing the impact
caused by wind farms on wildlife (Donazar et al., 2016). For
this reason, it is essential to gather as much as possible
information, consolidate consensus findings and investigate
discrepancies in results when searching for and implementing
solutions (Martinez et al., 2010). This approach allows for
progress in taking measures that truly provide efficient
solutions.
In this review, we have compiled and analyzed the pub-
lished literature on the impacts of wind farms on raptors
worldwide. Unlike previous works (e.g. Kikuchi, 2008; Wat-
son et al., 2018; Fernandez-Bellon et al., 2019; Conkling
et al., 2021), we have not only summarized the effects of
wind farm construction on birds but have also collected,
integrated and analyzed the solutions proposed by various
authors and their long-term effectiveness. To accomplish this,
we have organized available information based on the taxo-
nomic order of the studied raptors, size, flight type, diet, the
impacts they experience, their effects, observed behavior and
the methods employed to obtain information. This study syn-
thesizes all available information to date, consolidates con-
sensus findings from the literature and highlights
discrepancies among different studies to emphasize areas that
should continue to be investigated. Additionally, this study
underscores the importance of seeking solutions and verify-
ing their effectiveness to mitigate impacts on the most vul-
nerable species and promote their conservation on a global
scale.
Materials and methods
To gather the available literature on the impact of wind
farms on raptors, we conducted a search in the Google
Scholar and Scopus databases, spanning records up to June
2024. The parameters used for the search were as follows:
Title OR Abstract OR Keywords =(‘Wind farm’OR
‘Wind-farm’OR ‘Windfarm’OR ‘Wind turbine’OR
‘Wind-turbine’OR ‘Wind farms’OR ‘Wind power’OR
‘Wind-power’OR ‘windmill’) AND (‘Raptor’OR ‘Raptors’
OR ‘Rapt*’OR ‘Soaring bird’OR ‘Soaring-bird’OR ‘Soar-
ing birds’OR ‘Bird of prey’OR ‘Eagle’OR ‘Vulture’OR
‘Kite’OR ‘Harrier’OR ‘Condor’OR ‘Falcon’OR ‘Owl’).
This comprehensive search employed the primary terms
used to investigate the effects of wind farm installation on
raptors (Table 1). It is important to note that the search was
limited exclusively to scientific articles published in English
and in journals included in the Science Citation Index (SCI).
Works published as ‘gray literature’such as technical reports,
environmental impact studies, reports and assessments for
public administrations and environmental authorities, under-
graduate or master’s theses, as well as presentations at spe-
cific national and international conferences on the subject,
were not included in this review due to the lack of a peer
review scrutiny.
For the analysis of information, we incorporated the type
of methodology used for data acquisition (Table 2). Addi-
tionally, we classified the raptors by taxonomic order, size,
diet, and flight type.
For each article, we recorded the study period (i.e. start
and end dates) as well as the publication year to assess
changes in publications over time. Additionally, we added
information about the country and continent where each arti-
cle was conducted to evaluate the possible existence of geo-
graphic biases in the publications. Lastly, we noted whether
the published studies had declared conflicts of interest, or if
they had not.
For the data analysis, we used the R software (version
4.3.3) and R-Studio (version 2023.12.1 +402). Each of the
parameters was divided into categories (Tables 1and 2).
Subsequently, we conducted a systematic comparison by
2Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

calculating the number of articles per category and the per-
centage they represented of the total for that category. To
represent the geographic distribution of the data obtained, we
used QGIS version 3.16.
Results
After data filtering, we obtained a total of 216 scientific articles
specifically addressing the impact of wind farms on raptors.
Table 1 Variables included in this work to categorize the effects of the installation of wind farms on raptors
Term or variable Definition
Type of wind
farm
Classification of wind farms based on the following categories
1Onshore (wind farms located on land)
2Offshore (wind farms located at sea)
Study
characteristics
Classification of articles based on whether they studied a single species (monospecific) or multiple species (multispecific)
Topic Classification of articles based on the information they aimed to obtain, subcategorized as
1Predictions: Articles that used predictive models to study future scenarios for raptors due to the presence of wind
farms
2Risk Zones: Articles whose primary purpose was to study areas with a high risk of collision for raptors
3Mortality Detection: Articles primarily focused on studying raptors that died as a result of collisions with wind farms
4Consequences: Actions related to wind farms that generate a range of impacts on raptors, without specifying their
duration over time
5Long-term Consequences: Actions related to wind farms that have prolonged impacts on raptors, specifically extend-
ing beyond a period of 6.5 years (being this the lowest value employed by the analyzed papers)
6Solutions: Articles that studied potential solutions to reduce the impact of wind farms
7Efficacy of Solutions: Articles that sought to determine the effectiveness of implemented solutions
Adverse effects Negative impacts on raptors in the literature, categorized in this present study as
1Behavior: Alterations in a species’ behavior as a consequence of the presence of a wind farm. Subcategorized in this
study as avoidance (alteration of flight path or altitude to avoid potential collisions with wind turbines), or non-
avoidance. Following May et al.(2015) classification, we studied avoidance at different scales: macro-avoidance (terri-
tory abandonment or avoidance of specific areas [i.e. disuse]), meso-avoidance (avoidance of specific turbines) and
micro-avoidance (last-minute changes in flight directions and altitudes)
2Mortality: Number of raptors that die as a result of collisions with wind farms. Subcategorized as: increase, decrease
(articles considering the application of solutions that aid in reducing collisions), local extinction (articles considering an
increase in mortality that could lead to species extinction in the long term), risk zones (articles documenting raptor
mortality within zones determined as high risk under specific conditions) and no effects (articles not reporting
mortality)
3Home Range: Areas used by raptors for their daily activities. Subcategorized as: increase, decrease, risk zones (arti-
cles that analyzed home ranges within what they considered collision risk zones) and no effects
4Population Trend: Viability of a population over time, considering the number of individuals, reproduction rate,
emigration/immigration rate and annual mortality rate. Subcategorized as: increase (articles reporting positive popula-
tion trends), decrease (articles reporting negative population trends) and no effects
5Abundance: Difference in the total number of birds counted before and after the installation of wind farms. Subcate-
gorized as: increase (articles reporting an increase in the number of observed birds within a wind farm after installa-
tion), decrease (articles reporting a decrease in the number of birds after wind farm installation), risk zones (studies
on raptor abundance within what they considered collision risk zones) and no effects (articles not reporting changes
in the local abundance of species)
Size Large raptor: Wingspan >2m
Medium-sized raptor: Wingspan between 1 and 2 m
Small raptor: Wingspan <1m
Diet Classification of the dietary type of each raptor based on the most common food source. Studies involving the examination
of more than one raptor have been categorized as ‘More than one’
1Strict scavengers
2Strict predators
3Opportunistic predators that occasionally scavenge
Flight type Categorization of articles based on the flight type of the studied species considering that these are the flights they
predominantly undertake (Ferguson-Lees & Christie, 2001), acknowledging that they are not exclusive and may employ
other types of flights under specific circumstances, categorized as:
1Flapping: Flight involving the rapid motion of wings for propulsion
2Soaring: Flight primarily relies on thermal and orographic wind currents for movement without the need for wing
flapping
3Flapping and Soaring: A combination of both flapping and soaring flight types
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 3
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

The majority of the articles focused on species from the Order
Accipitriformes (n=123) and were conducted in onshore
wind farms (n=202). Raptors with a combination of wing
flapping and soaring flight were the most studied (n=162).
Studies that simultaneously included raptor species of all sizes
were the most abundant (i.e. multi-species studies) (n=68).
The most commonly employed method for data collection was
local monitoring (n=72). The most frequently observed
adverse effects and consequences were the study of risk zones
within raptor foraging areas (n=62) and increased mortality
(n=48), respectively. Interestingly, there is a scarcity of arti-
cles specifically addressing the impact of wind farms on Strigi-
formes with mono-specific studies (n=6) (e.g. Smallwood
et al., 2007;L

opez-Peinado et al., 2020).
Main topics of interest: Geographical and
temporal distribution
Most of the articles were published in Europe (49.5%) and
America (33.3%) specifically in North America and South-
western Europe with the United States and Spain having the
highest number of publications, at 68 and 34 respectively
(Fig. 1). While in Europe, Asia and Oceania (37.4%, 37.5%,
50.0% respectively), the articles primarily focused on study-
ing the consequences of wind farms, in America and Africa,
they mostly centered on studying risk zones for raptors
(26.0% and 36.4%, respectively). In articles where the study
area included more than one continent, the consequences of
wind farms on raptors were predominantly analyzed (58.3%)
(Fig. 2).
The number of articles analyzing the overall impact of
wind farms on raptors has increased over time. Specifically,
the study of the specific effects of wind farms on raptors has
generated greater interest over the years (from 0.9% of arti-
cles in 2004 to 9.7% in 2022). There has also been an
increased interest in studying collision risk zones around
wind turbines (from 1.6% in 2002 to 6.5% in 2022).
Although virtually all aspects of scientific paper production
have increased tremendously over the past years
(Evans, 2013), this increase is likely facilitated by the expan-
sion of built wind turbines and thus potential study areas
facilitating such studies.
Table 2 Classification of methodologies used for the analysis of the effects of wind farms on raptors
Method Description References
Database
literature
Processing of information obtained from pre-existing
databases or scientific papers before the onset of the study
For example, Smallwood (2013); Loss, Will, & Marra (2015);
Hunt & Watson (2016); Allison et al.(2017); Law and
Fuller (2018)
Local monitoring Establishment of fixed observation points and/or linear
transects designed for the purpose of quantifying the
number of birds traversing wind energy facilities
For example, Hilgerloh, Michalik, and Raddatz (2011);
Dohm et al.(2019); McClure et al.(2021a); Cervantes,
Martins, and Simmons (2022)
Wind farm
revision
Searching for raptor carcasses in the vicinity of wind turbines
to estimate mortality resulting from collisions
For example, Smallwood, Rugge, & Morrison (2009);
Smallwood et al.(2010); Huso et al.(2015); DeVault
et al.(2017); Katzner et al.(2017)
Cameras Placement of visible light and infrared video cameras on the
rotors of wind turbines to collect information about birds
that engage in flights near the installations
Murai et al.(2015); Therkildsen et al.(2021); McClure
et al.(2021c); Linder et al.(2022)
GPS/GSM Electronic devices powered by internal batteries or small solar
panels, which facilitate the determination of the bird’s
location. These devices employ various data transmission
methods, including utilization of the mobile phone network,
the Argos system, or local data retrieval in the field through
the deployment of a reception base station
For example, Miller (2012); Rushworth and Krueger (2014);
Reid et al.(2015); Sur et al.(2018)
Radio-tracking Very High Frequency (VHF) radio devices that enable the
determination of individual locations through in situ
triangulation
For example, Hunt et al.(1999); Hunt (2002); Kolar (2013);
Kolar and Bechard (2016)
Radar A method enabling the acquisition of information regarding
birds passing in close proximity to wind farms through the
identification of signals based on radar pulses
Baisner et al.(2010); Villegas-Patraca, Cabrera-Cruz, &
Herrera-Alsina (2014); Cabrera-Cruz and
Villegas-Patraca (2016); Skov et al.(2016)
Visual marks or
tags
Individual identification technique that enables the
determination of the origin of raptors through the
placement of distinctive elements (typically on the tarsus or
wings). This method also allows the inference of population
size using capture, mark and recapture methods, among
others. Mark-recapture studies were used to estimate
survival rates of wind farm exposure
For example, Martinez-Abrain et al.(2012); Sanz-Aguilar,
De Pablo, and Antonio Donazar (2015)
Combination of
methodologies
Utilization of multiple of the aforementioned methodologies
within a single study
For example, Schaub (2012); Bay et al.(2016); Dohm
et al.(2020); Santos, Marques, and May (2020); Duriez
et al.(2022)
4Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

Figure 1 Geographic distribution of research papers that investigated the effects of wind farms on raptors across the world.
Figure 2 Percentage of research papers that investigated the effects of wind farms on raptors across the world, by topic and continent (see
text for details).
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 5
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

Methods used for data collection
Articles employing local monitoring as a data collection
method increased over time. Despite being the most widely
used technology, the method that has experienced the most
substantial growth from 2010 onwards has been the use of
GPS/GSM transmitters (from 2.3% in 2012 to 20.5% in
2022). To the best of our knowledge, radio-tracking was the
first methodology used for the specific case of our study
(Hunt et al., 1999), but in the latest decade, it has fallen out
of use due to the rise of GPS/GSM transmitters. UV light
was used in a single article to observe if raptors avoided
wind farms (Hunt, McClure, & Allison, 2015).
The use of cameras for raptor detection and subsequent
image processing for identification is a new methodology.
Although it has been proposed for other porpoises such as
techniques for counting and estimating bird-wind turbine col-
lisions (Desholm et al., 2006), it was employed for studying
the impact of wind turbines on raptors in 2015 (Murai
et al., 2015) and has continued to be implemented in the last
decade (13 articles in 9 years). The two least employed
methods have been reading raptor visual marks or tags and
radar, with only two (i.e. Martinez-Abrain et al., 2012;
Sanz-Aguilar et al., 2015) and four articles (i.e. Baisner
et al., 2010; Villegas-Patraca et al., 2014; Cabrera-Cruz &
Villegas-Patraca, 2016; Skov et al., 2016), respectively. The
combination of multiple techniques has increased in the last
two decades (from 5.3% in 2004 to 15.8% in 2022).
Regarding the type of wind farms, the majority of articles
focused on the impact of onshore wind farms (93.5%), while
offshore wind farms accounted for a minimal percentage of
the total (3.7%). Those articles that considered both types of
farms were a minority (2.8%). Most data collection methods
were employed in onshore wind farms. However, it is worth
noting that in the case of radar, most of the articles were
conducted in offshore wind farms (75.0%).
Adverse effects on raptors
Raptor mortality was the most studied adverse effect over
time (30.6%), followed by changes in home range area
(30.1%) and changes in behavior (25.4%). However, varia-
tions in abundance (8.3%) and alterations in population
trends (5.6%) have been studied since the late 1990s to the
present but to a lesser extent.
All considered adverse effects in this review were studied
in onshore wind farms. However, in Offshore areas, all nega-
tive effects were reported except for changes in population
trends, although to a lesser extent than in the case of
Onshore areas. In articles that simultaneously studied the
effects in onshore and offshore wind farms, alterations in
behavior (50.0%) and home range (50.0%) were considered.
All adverse effects have been studied for species of the
order Accipitriformes. For Strigiformes, changes in behavior,
abundance (16.7% each), home range and mortality (33.3%
each) were studied. In the case of Falconiformes, the effect
on mortality and home range (40.0% each) and variations in
population trends (20.0%) were studied. All effects were
studied in studies that considered more than one order.
Regarding the study of flight types in relation to different
effects, the majority of papers report the effects of raptors
with flapping and soaring flight types together (75.1%). For
species with flapping flight, articles primarily focused on
analyzing changes in raptor behavior (36.7%). In papers that
exclusively studied soaring raptors, the effects on mortality
were predominantly examined (45.8%) (Fig. 3).
Figure 3 Number of research papers in relation to the adverse effects investigated categorized by flight type.
6Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

Consequences of adverse effects
From the analysis of adverse effects and their consequences,
the following results were obtained:
Abundance
In 72,2% (n=13) of the articles that studied bird abundance
before and after the installation of wind farms, a decrease in
the number of birds after installation was observed. The
declines in abundance were studied in both strict scavenger
species (7,7%) and strict predator species (23,1%), as well as
opportunistic species alike (38,5%). In multi-species studies,
declines in abundance were also reported (30,8%). All these
articles were published in Europe, America and in those arti-
cles in which more than one continent was considered and
reported a decrease in population sizes of Aquila chrysaetos,
Circus cyaneus, Neophron percnopterus, Milvus milvus, Cir-
cus aeruginosus, Accipiter nisus, Accipiter gentilis, Pernis
apivorus, Buteo buteo, Buteo lagopus, Pandion haliaetus,
Falco tinnunculus, Falco columbarius, Falco subbute, Cir-
caetus gallicus and Gyps fulvus (e.g. Watson & Whit-
field, 2002; Campedelli et al., 2014; Olea & Mateo-
Tomas, 2014). In 11,1% of the articles (n=2), an increase
in abundances was reported. After 8 years since the installa-
tion of wind farms, increases in the abundances of popula-
tions of Cathartes aura, Buteo jamaicensis, Accipiter sp,
have been reported using local monitoring in the United
States (Dohm et al., 2019). In Europe, an increase in abun-
dances has also been reported using local monitoring after
6.5 years of wind farm installation for Aquila fasciata,
Aquila chrysaetos, Circaetus gallicus, Gyps fulvus and Bubo
(Farfan et al., 2017). The diet of the abovementioned species
ranges from strict scavengers to strict predators and opportu-
nistic feeders. Two articles were classified as ‘no negative
effect’because they proposed solutions to mitigate the
impacts of wind farms (11,1%) (Schindler et al., 2015; Law
& Fuller, 2018). The remaining 5,6% corresponds to a single
article in which bird abundance was analyzed before and
after the installation of the wind farm within what the
authors considered a collision risk zone (Telleria, 2009).
However, in a previous review, it was reported that some of
the results provided by articles studying raptor abundances
before and after wind farm installations were not adequately
conducted (e.g. incomplete studies, lack of standardization,
or absence of detection probability estimates). This under-
scores the importance of conducting comprehensive studies
that observe long-term variations in abundances (Conkling
et al., 2021).
Home range
In the vast majority of articles that studied space use (95.4%,
n=62), collision risk zones were defined (i.e. spaces within
the home range area that could imply a collision risk for rap-
tors). An increase in home range area was observed in Nisaetus
nipalensis (Asia) during various phases of wind farm construc-
tion (Nishibayashi, Kitamura, & Yoshizaki, 2022). There was
one article that studied the effectiveness of solutions concern-
ing the study of home range area and how wind farms’pres-
ence affected it. This article was categorized as having ‘no
negative impact’(Sur et al., 2018). Reductions in home range
were observed in Bubo bubo (Husby & Pearson, 2022) due to
the proximity of wind farms to nesting sites (41% reduction in
the territories of individuals whose nests were located in closer
proximity to the wind farms). In addition, a decrease was
observed also in the home range areas of Haliaeetus albicilla in
nests located farther from wind farms, whereas the home range
areas increased in nests situated closer (May et al., 2013).
Mortality, reproduction and population trends
Overall, 72.7% of the papers reported an increase in mortality
(n=48). In those studies where measures were implemented
to reduce mortality, a decrease in mortality was observed
(10.6%, n=7). The decrease in mortality was studied by com-
paring the number of collisions before and after the implemen-
tation of the solution. Among the solutions implemented in the
studies, notable interventions included on-demand stopping
(tested for vultures in Europe [de Lucas et al., 2012a; Ferrer
et al., 2022]), the removal of attractants such as food (tested in
a species of Falco in Europe [Pescador, Gomez Ramirez, &
Peris, 2019]), or the development of risk maps (tested in Aquila
verreauxii in Africa [Murgatroyd, Bouten, & Amar, 2021]).
Out of all the articles 7.6% (n=5) predicted the long-term
local extinction of the studied species as a result of the presence
of wind farms; 7.6% (n=5) did not observe any negative
effects; and in 1.5% (n=1), mortality associated with collision
risk zones was observed (i.e. an article that established collision
risk zones and studied mortality within them). Interestingly,
there was a paper whose primary focus was on the impact on
reproduction, and it asserted that a decrease in birth rates
occurred after the installation of wind farms (Balotari-Chiebao
et al., 2016).
Finally, 75.0% (n=9) of the articles reported a decrease in
population trends and 8.3% (n=1) did not observe negative
effects on population trends. All articles that documented a
decline in population trends did so for species characterized by
a long lifespan: Aquila chrysaetos (Hunt et al., 1999), Neo-
phron percnopterus, Gyps fulvus (Garcia-Ripolles & Lopez-
Lopez, 2011) and Haliaeetus albicilla (Dahl, 2014). These
observations were primarily conducted through field observa-
tions, although one of the articles employed radio-tracking
methods (Hunt et al., 1999). The findings from these studies
suggested that the decline in population primarily stemmed
from adult mortality. With regard to those articles that reported
an increase in population trends (16.7%), they correspond to
two studies in which long-term research was conducted follow-
ing the installation of wind farms, observing recoveries in pop-
ulation trends over time (Farfan et al., 2017; Farf
an
et al., 2023).
Behavior
In 74.6% of the articles reporting changes in raptor behavior
as a consequence of the presence of wind farms, avoidance
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 7
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

behavior was observed. However, in 12.7% of the studies,
avoidance behaviors were not observed and in 12.7%, no
negative effects were observed. From the articles that
reported avoidance as a consequence of wind farm presence,
9.8% reported increases in flight heights. There was a higher
number of articles in which avoidance behaviors were
reported (n=41) compared to those in which they were not
observed (n=7). Furthermore, 34.1% of the articles docu-
mented avoidance behaviors in small raptors, 29.4%
in small, medium and large raptors studied together, 9.7% in
large raptors, 14.6% in medium-sized raptors, 7.3% in
medium and large-size raptors and 4.9% in small and
medium-sized raptors studied together (Fig. 4). Of the arti-
cles reporting avoidance behaviors, 56.1% were limited to
the order Accipitriformes, 41.4% observed it in those where
more than one order was analyzed and 2.4% in the order
Strigiformes. Avoidance was neither detected nor absent in
raptors of the order Falconiformes in the papers analyzed in
this study. Of the articles that reported avoidance behavior,
75.7% were in species with flight types that combine soaring
with flapping flight, 24.4% observed it in flapping raptors.
None of the articles studied recorded the absence or presence
of avoidance in soaring raptors.
Furthermore, adhering to various types of avoidance
(May, 2015) it was determined that 9 papers reported macro-
avoidance, 12 meso-avoidance and 20 micro-avoidance.
Among the papers that examined macro-avoidance, 22.2%
was observed in opportunistic raptors, 22.2% in strict preda-
tors and the remaining 55.6% were studied in multispecific
papers (diet not analyzed). In the case of meso-avoidance,
16.7% was observed in opportunistic raptors, 33.3% in strict
predators and the remaining 50.0% was studied in multispe-
cific papers (diet not analyzed). In the case of micro-
avoidance, 35.0% was observed in opportunistic raptors,
25.0% in strict predators and the remaining 40.0% was stud-
ied in multispecific papers (diet not analyzed).
Solutions
In addition to the search for solutions, it is crucial to be
acquainted with tools that facilitate the identification or
effectiveness assessment of these solutions. We have com-
piled those used in the literature reviewed (Table 3).
Following the hierarchy employed by Allison
et al.(2017), we have classified various solutions and useful
applications for solution implementation based on: (i) avoid-
ance of the situation causing a negative impact and (ii) mini-
mization of the generated impact.
There are various solutions for the avoidance or minimiza-
tion of the impact of wind farms on raptors (Table 4).
Discussion
Raptors are one of the groups of birds most vulnerable to the
presence of wind farms (Desholm, 2009; Wulff, Butler, & Bal-
lard, 2016; May et al., 2021; Balotari-Chiebao, Valkama, &
Byholm, 2021), although the degree of impact and vulnerability
can vary depending on species (Smallwood et al., 2009;
Hernandez-Pliego et al., 2015; Schuster et al., 2015; Dohm
et al., 2019), habitats (Barrios & Rodriguez, 2004; Schuster
Table 3 Applications that can serve as a guide for the implementation of solutions to avoid negative effects of wind farms on raptors
Mitigation
hierarchy
Proposed
application Description Applications References
Avoid Habitat
suitability
models
Models that examine the best and
worst areas for wind farm installation
based on raptor habitat use
1Modifying the planning of wind
farm installation
2Reducing the number of turbines
in it
For example, Murgatroyd
et al.(2021); Ng et al.(2022)
Minimize BACI
studies
Studies in which a Before and After
Control Impact (BACI) approach is
employed. In these studies,
information is compared before and
after the installation of the wind
farm and between control and
experimental sites
1To gain a comprehensive under-
standing of raptor habitat utiliza-
tion and behavioral changes
occurring after the installation of
wind farms
2To assess the effectiveness of
models predicting the impact of
wind farms and to calibrate them
Garvin et al.(2011); Dahl
et al.(2012); Campedelli
et al.(2014); May et al.(2020);
Conkling et al.(2021);
Therkildsen et al.(2021)
Figure 4 Number of papers reporting avoidance or lack of avoid-
ance behavior in relation to raptors’ size.
8Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

et al., 2015; Watson et al., 2018) and the different technologies
used by each wind farm (Hunt, 2002; Kikuchi, 2008; Ster
ze &
Pogacnik, 2008; Schuster et al., 2015). Despite the variability
in reported results in the scientific literature, there are common
patterns in how birds interact with wind turbines. This allows
for the determination of general aspects of knowledge acquired
over time about the impact of wind farms on raptors and the
establishment of some minimum consensuses (Watson
et al., 2018).
Geographical and temporal variation
The study of mortality caused by wind farms has been
extensively investigated over time. Variations in behavior
and raptor foraging areas have also been widely studied. As
these are the most visible impacts that can be observed fol-
lowing the installation of wind farms, these aspects have
been extensively reported in the scientific literature.
Because onshore wind farms are predominant worldwide,
they have been studied more over time (e.g. Hunt
et al., 1999; de Lucas et al., 2008; Monti et al., 2023).
However, the number of studies focusing on the impacts of
offshore wind farms on raptors is much smaller. This could
be attributed to the fact that the majority of raptors do not
frequent marine areas, thus fewer efforts are invested in
understanding the impacts of offshore windfarms. Further-
more, there are logistical difficulties of research the impacts
of windfarms at sea (Schuster et al., 2015).
Among all the groups of raptors studied, the papers focus-
ing on Accipitriformes have predominated over time (e.g.
Murgatroyd et al., 2021). This may be because it is the larg-
est group of raptors and likely includes more vulnerable spe-
cies (Thaxter et al., 2017). The concern about understanding
the effects and consequences of wind farms on Accipitri-
formes has led to a larger number of articles, and this num-
ber has remained relatively constant over time. The number
Table 4 Proposed solutions in the literature that could be applied to avoid negative effects of wind farms on raptors
Mitigation
hierarchy
Proposed
Solution Description Applications References
Avoid Turbine
micro-siting
Alteration of turbine distribution based
on the risk predicted by habitat
suitability models
1Removal of turbines on the most fre-
quently used mountain ridges by soar-
ing raptors
2Avoidance of nesting areas
3Avoidance of areas that are heavily
used or where more food is available
Allison et al.(2017);
Pescador et al.(2019)
Minimize Repowering Reduction in the number of wind
turbines and an increase in the rotor
height of those that are retained
Reduction in collision risk due to the taller
rotors of the new wind turbines. At least
for species that fly at low height (e.g.
harriers). (High cost)
Hunt and Hunt (2006);
Smallwood &
Karas (2009);
Schaub (2012)
Minimize Shut down on
demand of
specific
turbines
Allows for the shutdown of those wind
turbines over which a raptor is
predicted to fly at a collision-risk
altitude
Allows for the reduction of mortality
among the most vulnerable raptors with
only a minimal decrease in energy
production (only a 0.07% reduction). Its
effectiveness has been demonstrated
Smallwood
et al.(2009); de Lucas,
Ferrer, and
Janss (2012b); Ferrer
et al.(2022)
Minimize Elimination of
attractants
Removal of elements that may attract
raptors to wind farms
1Removal of food sources
2Reduction of perches near the wind
farm
3Removal of carcasses near the wind
farm
Allison et al.(2017);
Pescador et al.(2019)
Minimize Installation of
repellents to
reduce
collision
probability
Placement of devices in the middle to
deter raptors
1Painting the wind turbine blades to
make them more visible. Contradic-
tory results among studies
2Installation of UV lights to create
visual disturbances. This measure has
not been effective for the studied
species
3Generation of annoying sounds. The
installation of these elements has not
been shown to reduce collisions
Barrientos et al.(2011);
May et al.(2013);
Hunt et al.(2015);
Allison et al.(2017)
Minimize Nest removal Removal of unoccupied nests by raptors
before the breeding season begins or
the disabling of areas where new nests
could be established
Preventing raptors from nesting within
wind farm facilities. There is controversy
regarding its effectiveness and ethical
considerations associated with such
measures
Hunt and
Watson (2016); Allison
et al.(2017)
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 9
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

of species studied in each research varied widely depending
on the type of information desired and the methodology used
to obtain that information (Dohm et al., 2019). Thus,
single-species and multi-species studies have been published
extensively over time.
The continents where the most research has been published
over time are America and Europe. This could be because these
are two continents with a large expansion of these infrastruc-
tures (Allison et al., 2017; Farfan et al., 2017) and congregate
the countries with high economic income per capita. Therefore,
they devote efforts to studying the impacts of wind farms on
the most vulnerable species. The absence of articles from many
Eastern countries such as Russia or China, and Southern
nations, predominantly across the African continent, suggests a
potential loss of scientific information, probably due to publica-
tions in non-English-languages (Konno et al., 2020; Amano
et al., 2021). Although there are few articles published in
Africa, there has been an increase in the number of articles on
the continent in recent years (Reid et al., 2015; Cervantes
et al., 2022). This may be driven by the increasing number of
these infrastructures on the continent (McClure et al., 2021c),
despite existing economic disparities worldwide.
There is variation in the number of publications across dif-
ferent continents, but the information reported in some of them
is comparable because the concern about the impact of wind
farms on raptors is shared worldwide. Despite the considerable
variation in habitats, species and technologies used, much of
the published information can be grouped and shared to sim-
plify and facilitate future research. Furthermore, many of the
findings contributed by researchers can be applied to different
species inhabiting various parts of the world, thereby reducing
the preparation and work time for future investigations.
Methods of data acquisition
The prevalence of local monitoring in most articles can be
attributed to its cost-effectiveness, allowing for the collection
of data on the number of birds crossing a wind farm, their
altitude and flight direction. However, this methodology
heavily relies on the observation skills and perception of
field personnel, making it inherently variable (Madders &
Whitfield, 2006; Douglas et al., 2012). Additionally, with
larger wind farms, the detection of species through visual
observations becomes more complex (Sur et al., 2018). Local
monitoring is also a technique that varies depending on the
field effort. Studies have shown that its efficiency improves
in surveys where researchers spend the entire day in the field
conducting observations (Chabot & Slater, 2018). Despite
being the most commonly used methodology, there may be a
vast array of different questions and different techniques to
address them. Therefore, standardizing protocols can be a
difficult task, making result comparisons challenging.
On the other hand, the use of GPS/GSM provides a viable
alternative for detecting birds that pass close to wind farms, as
it reduces the subjectivity associated with sampling effort and
the experience of personnel (Kikuchi et al., 2019). Further-
more, it can facilitate early hazard detection (Watson
et al., 2018). However, GPS/GSM data collection requires large
sample sizes to draw conclusive information, which may not
always be feasible for some species (L
opez-L
opez, 2016). The
papers examined in this study that utilized GPS/GSM for data
collection were able to analyze variations in behavior (e.g.,
changes in altitude, flight directions, or avoidance behavior)
with a drastically reduced margin of error (e.g. Katzner
et al., 2012; Sheppard et al., 2015; Mojica, Watts, & Tur-
rin, 2016). Numerous applications exist, such as selectively
stopping wind turbines when a GPS-equipped raptor enters a
wind farm’s area (Sheppard et al., 2015), early collision pre-
vention (Watson et al., 2018), or even calibration of other
methods to ensure they are being conducted correctly (Sur
et al., 2018). Radio-tracking is a similar methodology to GPS/
GSM but is less precise as it requires triangulation of bird posi-
tions, necessitates fieldwork to locate marked raptors, and also
relies on large sample sizes (L
opez-L
opez, 2016). For these
reasons, coupled with the availability of increasingly light-
weight, smaller and cheaper transmitters, it is a technology that
is practically obsolete, at least for raptors (though not for other
animal groups like bats) (Gottwald et al., 2019). There is cur-
rently a new network, the Motus Wildlife Tracking System, that
employs automated radio telemetry. This system is designed to
study the movements of small flying animals, such as small
birds. This new tool utilizes a single frequency at receiver sta-
tions across a wide geographic scale (Crewe et al., 2017; Grif-
finet al., 2020). Furthermore, it enables continuous and
simultaneous tracking by multiple researchers. The develop-
ment and implementation of this new technology can provide
extensive information regarding the impact of wind farms on
smaller raptors across a large spatial scale, allowing for the
simultaneous study of various species.
For the calculation of bird mortality, carcass searches are
the most commonly used methodology (e.g. Smallwood &
Thelander, 2008; Smallwood & Karas, 2009). However, to
obtain an accurate estimate of mortality, it is necessary to
study the carcass disappearance rate (i.e. to estimate birds
that have died but were not found due to scavenger activity)
(Wilson, Hulka, & Bennun, 2022). In this methodology,
there is also a lot of variation depending on the effort of the
researcher and the type of carcass used (Smallwood, 2013;
DeVault et al., 2017). Raptors are the carcasses that persist
the longest, so some studies suggest that using other birds as
carcasses to calculate the disappearance rate may alter the
actual mortality rate (Smallwood et al., 2010; Hallingstad
et al., 2018; Wilson et al., 2022). Furthermore, the absence
of carcasses does not correlate with the absence of collisions,
so some authors developed equations that allow estimating
the number of collided birds based on the probability that
these birds are within the study area (Huso et al., 2015).
Radar, due to its high economic cost and logistical difficul-
ties, is the least used methodology. This technology is based on
the use of electromagnetic waves to determine the type of rap-
tor, its position and its speed (Schekler et al., 2023), which
enables observations of birds that are not easily visible to the
naked eye (e.g., migratory movements or nighttime bird dis-
placements). However, deep learning methods are required to
distinguish between the different elements it detects and elimi-
nate radar echoes that limit species differentiation (Schekler
10 Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

et al., 2023). In some cases, direct field observations are also
needed to calibrate the information obtained (Panuccio, Gha-
fouri, & Nourani, 2018).
The use of cameras triggered by the passage of birds near
wind turbines allows for the determination of the number of
birds crossing, and in some cases, the distinction between
species and ages (Murai et al., 2015). Software based on
artificial intelligence is employed to discern between the spe-
cies present in the images (McClure et al., 2021c). However,
the range of photography is not very extensive, so it may
not capture all species passing near wind turbines. Addition-
ally, these identification programs have certain associated
errors, requiring machine learning supervision (McClure,
Martinson, & Allison, 2018).
The use of visual marks or tags for the calculation of sur-
vival estimates in raptors has the drawback that it requires
reading the marks to confirm the presence of an individual in a
specific location, depending strictly on the researcher’s effort
and detection ability. While other methodologies can provide
information such as speed, flight direction, or altitude, reading
bands only allow the study of the presence or absence of an
individual in a specific location without additional information
about its origin (Strandberg, Klaassen, & Thorup, 2009).
The combination of methodologies for conducting studies
that can be comparable and replicable in other research is
crucial for obtaining results that can help reduce the impacts
of these infrastructures on raptors (Smallwood, 2013).
Establishing global consensus on potential negative effects
and their causes allows for a detailed examination of possi-
ble solutions to be implemented. Moreover, and most impor-
tantly, thanks to all the studies conducted to date, we can
proceed to develop effective measures to reduce negative
impacts and promote the conservation of raptors.
Lack of consensus on behavior and
population dynamics
Given the abundance of studies aiming to ascertain the
impacts of wind farms on raptors worldwide, there are vari-
ous aspects for which sufficient consensus is still lacking.
With regard to annual variations, there is variation in the
number of collisions depending on the season due to changes
in the behavior and abundance of raptors at different times of
the year (Barrios & Rodriguez, 2004; Carrete et al., 2012).
Peaks in mortality have been reported during months of migra-
tory activity (Barrios & Rodriguez, 2004; Smallwood
et al., 2007). However, there is a lack of consensus on whether
migratory raptors are the most affected (Kikuchi, 2008)orifit
is the local ones (Katzner et al., 2012; Schuster et al., 2015).
Yet, there is also a lack of consensus as to whether rap-
tors are differentially affected by gender and age factors.
Some studies have concluded that there are more young indi-
viduals in the vicinity of wind farms (Dahl, 2014), and they
exhibit lower avoidance behaviors (Watson et al., 2018). We
have only found one article that addresses the difference
between males and females concerning the risk of collision
(Heuck et al., 2020). In this article, it is mentioned that no
differences were found between the age of individuals of
Haliaeetus albicilla, but there were differences between
sexes. Males were more prone to collisions than females.
Perhaps this can be explained by the effort exerted by males
during the breeding season in the search for food.
Different studies argue that the reduction in the abundance
of raptors in a specific area due to the presence of wind
farms is temporary (Farfan et al., 2017; Dohm et al., 2019)
and can recover over time. These abundances were observed
following the long-term study of wind farms before and after
their installation (8 and 6.5 years, respectively). While the
first one has been debated due to the methodologies
employed (Santos et al., 2020), the results suggest the recov-
ery of some species in the study area. The diet of the stud-
ied species is highly varied and does not seem to be the
likely cause of their recovery. Nonetheless, there is no con-
sensus on this matter, as only two articles assert a recovery
of abundance, and one of them has been widely criticized. It
would be interesting to conduct further studies on this topic
to analyze whether raptors can indeed acclimate and recover
their abundance after extended periods of time.
Although not all studies report avoidance behavior, most
confirm that raptors are capable of detecting the presence of
a wind turbine and try to avoid it, regardless of the species
or its size (Villegas-Patraca et al., 2014; Cabrera-Cruz &
Villegas-Patraca, 2016). However, it should be noted that
certain species, such as vultures, are less likely to detect
wind turbines due to their predominantly downward vision
in search of carcasses, making them more vulnerable to col-
lision (Martin, Portugal, & Murn, 2012). Avoidances have
been observed in studies involving direct field observations
as well as those using GPS/GSM technology. In the latter,
precise changes in flight altitudes were observed following
the detection of wind farms, which indicates the presence of
avoidance behaviors (Johnston, Bradley, & Otter, 2014; Lin-
der et al., 2022). Moreover, changes in flight direction (John-
ston et al., 2014), displacement to other habitats (Marques
et al., 2020), or even shifts in nest locations (Dahl
et al., 2012) have also been reported. Among the various
types of avoidance (macro-avoidance, meso-avoidance and
micro-avoidance), there does not seem to be a relationship
with the diet. This may also be attributed to the fact that the
majority of articles were multispecies, and the diet could not
be analyzed individually for each species covered in them.
Recognizing areas of non-consensus is crucial for advancing
research on the effects of wind farms on raptors in a scientifi-
cally formal context. It underscores the dynamic and complex
nature of ecological interactions, emphasizing the need for
comprehensive investigations that consider various factors. By
acknowledging gaps in consensus, researchers can identify
specific aspects requiring further exploration, directing atten-
tion to critical areas where knowledge is limited.
Consensus on behavior and population
dynamics
Soaring raptors make use of orographic lift in the absence of
ascending thermal currents (e.g., in winter and during twi-
light hours) to ascend during their flights. Therefore, some
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 11
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

of the most dangerous wind farms are those with turbines
located on mountain ridges (Barrios & Rodriguez, 2004;
Katzner et al., 2012; Miller et al., 2014; Schuster
et al., 2015; Singh et al., 2016; Peron et al., 2017; Poessel
et al., 2018a). Additionally, soaring raptors, being large
birds, have less maneuverability in flight and tend to follow
routes that minimize energy expenditure. They follow pre-
vailing wind currents, which are also utilized by wind farms
to generate energy. In this regard, some studies demonstrate
a direct relationship between the distribution of dominant
wind currents and the distribution of mortality in Gyps fulvus
in wind farms (de Lucas et al., 2012b). Moreover, regardless
of size and flight type, in situations with adverse weather
conditions (i.e. strong winds or low visibility), raptors
engage in more high-risk flights (i.e. flight at rotor height)
(Johnston et al., 2014).
Regarding home range, articles reporting an increase have
observed it due to disturbance caused by different phases of
wind farm construction. This disturbance has led to a dis-
placement of the studied species towards areas farther from
the wind farm (Nishibayashi et al., 2022). In the case of
decreases, they have been observed in two different species:
Bubo bubo and Haliaateus albicilla (May et al., 2013;
Husby & Pearson, 2022). Both species decreased their forag-
ing areas as they were forced to move to other locations,
altering their movement patterns due to the disturbance from
the presence of wind farms.
Wind farms cause habitat degradation and habitat loss for
raptors due to flight disturbance (e.g., noise or reflections)
and the barrier effect (Balotari-Chiebao et al., 2021; Fern
a-
ndez-Bellon, 2020; Jacobsen, Jensen, & Blew, 2019). The
barrier effect limits their access and, as a result, leads to
avoidance behavior (Schuster et al., 2015). Additionally,
wind farms are often located in areas that are ideal for prey
hunting. Consequently, hunting grounds become disabled and
raptors must search for food elsewhere, resulting in a loss of
habitats used by raptors for their vital functions (Watson
et al., 2018).
In papers that studied the effect of wind farms on the
population dynamics of raptors, it was found that in species
with low individual density (i.e. threatened species), even
though the probability of collision is lower, wind farm
impacts affect population growth. This is because even a
slight increase in adult mortality can lead to local extinction
of a species in the short term, especially in long-lived spe-
cies (Jongejans et al., 2020). Other studies report that despite
the local mortality caused by wind farms, the persistence of
some species depends on the balance between population
mortality and the rate of immigration of new individuals
(Hunt et al., 1999; Martinez-Abrain et al., 2012; Katzner
et al., 2016; Watson et al., 2018). The articles examining
population trends observed a decline attributable to wind
farms (e.g. Hunt et al., 1999).
The breeding performance of some raptors can be affected
by the installation of wind farms. This is because nest site
selection and reproductive success depend largely on the
proximity of wind farms (Martinez et al., 2010; Kolar, 2013;
Balotari-Chiebao et al., 2016). For example, some raptors
avoid nesting within a 500 m radius of wind farms
(Pearce-Higgins et al., 2009), while in others, there are
reports of a lack of breeding individuals in the vicinity of
wind farms due to noise pollution, which could hinder prey
detection, especially in nocturnal raptors (L
opez-Peinado
et al., 2020).
There is a consensus that local raptor abundance does not
correlate with higher mortality (e.g. Ferrer et al., 2012; Hull
et al., 2013; Martin et al., 2018). The study of abundances
could be used as a method to determine where to install a
wind farm (Carrete et al., 2012) or to compare large-scale
raptor groups and similar species, but not for calculating col-
lision probability (Watson et al., 2018). Furthermore, there is
consensus regarding the use of sensitivity maps to identify
high-risk zones for wind farm installation. Some of the stud-
ied factors include the following: the presence of raptors fly-
ing at risk height (Vignali et al., 2022), wind resources in
raptor frequented areas (Miller et al., 2014; Balotari-Chiebao
et al., 2018), the abundance of raptors vulnerable to colli-
sions, proximity to breeding or feeding grounds (Perci-
val, 2005) and steep slopes (Singh et al., 2016; Poessel
et al., 2018b).
Solutions and conflicts of interest
A set of consensus management measures can be formulated
based on the information derived from research investigating
the impacts of wind farm on raptors. These measures are
essential for predicting and mitigating adverse effects effec-
tively in the long term, irrespective of the local or geo-
graphical context. Habitat suitability models have been
widely employed in the literature reviewed. These models
facilitate the creation of areas that are safer for raptors and
the identification of zones where installation should be
avoided. By utilizing these models, solutions such as relo-
cating specific turbines or siting wind farms in different
locations than originally planned can be implemented. It is
crucial to test these models to assess their accuracy in repre-
senting the reality of the studied species and to determine
their true utility.
Before-After-Control-Impact (BACI) designs are valuable
tools for evaluating the effectiveness of implemented solu-
tions or identifying potential solutions to be implemented.
Such tools can be essential for studying population trends of
species and understanding how these trends vary as a result
of the presence of wind farms (Dahl et al., 2012; Conkling
et al., 2021).
There are various solutions for the avoidance or minimiza-
tion of the impact of wind farms on raptors. Among the pro-
posed solutions aimed at avoiding impacts, turbine
micro-siting stands out. By utilizing sensitivity maps to iden-
tify high-risk zones, modifying the placement of the most
hazardous wind turbines can contribute to reducing mortality
for numerous vulnerable species (Bay et al., 2016). Regard-
ing solutions aimed at minimizing negative effects, repower-
ing has been also implemented. Although it may be
controversial, this solution allows for a reduction in the num-
ber of turbines and an increase in rotor height, thereby
12 Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

reducing the collision risk for species with lower flight pat-
terns (Smallwood & Karas, 2009). However, it could still
pose a risk to species with higher flight patterns. Emergency
shutdowns, or stop-on-demand systems, are also noteworthy.
These systems enable the wind farm to stop if a target spe-
cies approaches. This approach can be implemented on a
long-term basis, such as during specific seasons when the
study species is in the vicinity of the wind farm. Addition-
ally, it can be adaptive, involving manual or automatic obser-
vation of a specific species approaching particular wind
turbines. This solution has been implemented and has proven
to be effective (de Lucas et al., 2012b). Another proposed
and tested solution is the removal of attractants. The elimina-
tion of potential food sources or perches has proven effective
in reducing the number of collisions (Allison et al., 2017).
However, this practice in the long term could lead to the dis-
placement and abandonment of territories.
The installation of repellents has a very similar application
to the previously discussed solution. Auditory and visual
repellents have been installed on turbines in some wind
farms to make these elements more noticeable. One of the
main challenges with these elements is the diversity in the
vision and hearing abilities of each species. Acoustic repel-
lents could be effective, but since hearing ability varies
widely among species (nocturnal raptors are much more sen-
sitive to sounds than diurnal ones), they should be tailored
to species at higher risk (May et al., 2015). However, this
also poses a disadvantage, as they may work for some spe-
cies but not be effective for others. Visual repellents have
also been implemented, such as painting turbine blades black
(May et al., 2020), but we have not found any articles dem-
onstrating their effectiveness in raptors apart from the article
proposing it as a solution.
The removal of nests is also a proposed solution to pre-
vent the presence of raptors, especially young individuals,
near wind farms (Hunt & Watson, 2016). However, while
this practice may be effective, it can also lead to the aban-
donment of territories and the displacement of species.
The implementation of evaluation schemes to assess the
management measures is crucial to determine whether they
should be modified or retained (Allison et al., 2017; May
et al., 2021).
Another important challenge to address is the existence of
conflicts of interest. The disclosure of conflicts of interest
aims to reveal whether a private company has an interest in
publishing specific information that may favor its interests.
Interestingly, none of the examined papers included in our
review declared conflicts of interest. It is advisable to explain
and specify the possibility of their existence, as the data
could be misinterpreted or information could be masked
(Boutron et al., 2019). One potential solution for conducting
studies supported by renewable energy industries could
involve establishing a contract between the environmental
consultants or researchers and the company, stipulating that
the publication of results would always be honest, even if it
might potentially harm the contracting company. This con-
tract could be appended to further scientific papers to dem-
onstrate a genuine absence of conflicts of interest.
Future perspectives
Thanks to the compilation and sharing of existing consen-
suses published in scientific articles, we can focus more
efforts on aspects where sufficient knowledge is still lacking
or where a consensus has not yet been reached. Some possi-
ble lines of future research could include:
1 Verification of the effectiveness of proposed solutions,
including the effectiveness of deterrents for raptors, as
well as corrective measures over the 30-year lifespan of
wind turbines, and developing efficient compensatory mea-
sures tailored to the most vulnerable species in the study
area.
2 Calibration of predictive models using Before and After
Control Impact (BACI) techniques. Comparing conditions
before and after wind farm installation and between con-
trol and experimental sites to correct possible model errors
could enhance and complement existing information. Fur-
thermore, standardization of this approach is necessary for
cross-taxon comparisons.
3 Development of techniques to determine the number of
collisions occurring in offshore wind farms and gain a
deeper understanding of the impacts these types of farms
have on raptors.
Conclusions
Raptors are the bird group most vulnerable to the presence
of wind farms in their habitat. As a consequence, numerous
papers aim to clarify the most relevant impacts on raptors
and how these impacts could be reduced. Given the existing
knowledge and the results reported in the literature, it is evi-
dent that, despite variations among species, habitats and
types of wind farms, there is enough information to reach
the following consensus:
1 The reviewed articles report that wind farms have a nega-
tive impact on the population dynamics of raptors.
2 The combination of different methods for obtaining infor-
mation provides the possibility of obtaining comprehensive
and reliable data. An adequate combination could involve
using GPS/GSM for obtaining precise locations of vulner-
able species, along with direct field observations to esti-
mate bird abundances, and carcass searches to determine
mortality rates.
3 Most papers agree that raptor abundance decreases after
the installation of wind farms. In some cases, over time,
abundances might recover to levels similar to those before
wind farm installation.
4 The potential risk areas for raptors around wind farms
have been extensively studied. The home ranges decrease
as wind farms are farther from their territories and
increase when they are closer, according to the examined
articles.
5 After the installation of wind farms, increases in mortality
and declines in population trends have been reported. Fur-
thermore, the mortality of adult individuals drastically
affects population dynamics, especially in endangered
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 13
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

species. Nevertheless, using local abundances to calculate
mortality risk is not a reliable method, as there is no cor-
relation between pre-wind farm installation abundance and
collision risk.
6 There are more papers reporting avoidance behaviors of
raptors in relation to wind farms than studies that do not
report avoidance. However, there are various forms of
avoidance that are explored in diverse ways. Hence, there
still exist numerous knowledge gaps concerning this topic.
7 The presence of thermal updrafts and orographic uplift is
crucial for large raptors to gain altitude during flight.
Therefore, wind farms located on mountain ridges are
more dangerous for these species than those located in flat
areas. This negative effect is especially pronounced in
adverse weather conditions.
8 Although none of the articles reported conflicts of interest,
it would be essential to honestly declare the potential exis-
tence of conflicts, as the interpretation of results could
interfere with the particular interests of an electric sector
company.
9 Presenting solutions and, fundamentally, verifying their
effectiveness is crucial to mitigate the negative effects of
wind farms and promote raptor conservation. This is espe-
cially important in the context of the increasing installed
capacity of new wind farms due to growing energy
demand and the global decarbonization process in progress
worldwide.
Acknowledgments
We extend our sincerest gratitude to all scientists whose prior
work laid the foundation upon which our research is built. We
would like to thank three anonymous reviewers who provided
valuable insights on an early version of this paper. This paper
was conducted under the project ‘Synergistic effects and impact
of solar and wind power renewable energies on the spatial ecol-
ogy of large vertebrates tracked by high resolution GPS/GSM
telemetry’(reference: TED2021-131653A-I00) funded by the
Spanish Ministry of Science and Innovation (MCIN/AEI/
10.13039/501100011033) and European Union ‘NextGenera-
tionEU’/PRT funds.
Authors’ contributions
I.E.-D. and P.L.-L. conceived the idea. I.E.-D.: analyzed the
data and wrote the first draft of the paper. P.L.-L.: provided
the materials and revised the paper.
References
Allison, T.D., Cochrane, J.F., Lonsdorf, E. & Sanders-Reed, C.
(2017). A review of options for mitigating take of golden
eagles at wind energy facilities. J. Raptor Res. 51, 319–333.
Amano, T., Berdejo-Espinola, V., Christie, A.P., Willott, K.,
Akasaka, M., B
aldi, A., Berthinussen, A. et al. (2021).
Tapping into non-English-language science for the
conservation of global biodiversity. PLoS Biol. 19,
e3001296.
Bailey, H., Senior, B., Simmons, D., Rusin, J., Picken, G. &
Thompson, P.M. (2010). Assessing underwater noise levels
during pile-driving at an offshore windfarm and its potential
effects on marine mammals. Mar. Pollut. Bull. 60, 888–897.
Baisner, A.J., Andersen, J.L., Findsen, A., Granath, S.W.Y.,
Madsen, K.O. & Desholm, M. (2010). Minimizing collision
risk between migrating raptors and marine wind farms:
development of a spatial planning tool. Environ. Manag. 46,
801–808.
Balotari-Chiebao, F., Brommer, J.E., Niinimaki, T. &
Laaksonen, T. (2016). Proximity to wind-power plants
reduces the breeding success of the white-tailed eagle.
Anim. Conserv. 19, 265–272.
Balotari-Chiebao, F., Brommer, J.E., Saurola, P., Ijas, A. &
Laaksonen, T. (2018). Assessing space use by pre-breeding
white-tailed eagles in the context of wind-energy development
in Finland. Landsc. Urban Plan. 177, 251–258.
Balotari-Chiebao, F., Valkama, J. & Byholm, P. (2021).
Assessing the vulnerabilityof breeding bird populations to
onshore wind-energy developments in Finland. Ornis Fenn.
98,59–73.
Barrientos, R., Alonso, J.C., Ponce, C. & Palacin, C. (2011).
Meta-analysis of the effectiveness of marked wire in
reducing avian collisions with power lines. Conserv. Biol.
25, 893–903.
Barrios, L. & Rodriguez, A. (2004). Behavioural and
environmental correlates of soaring-bird mortality at
on-shore wind turbines. J. Appl. Ecol. 41,72–81.
Battisti, C., Ferri, V., Luiselli, L. & Amori, G. (2020).
Introducing ecological uncertainty in risk sensitivity indices:
the case of wind farm impact on birds. Zool. Ecol. 30,11–
16.
Bay, K., Nasman, K., Erickson, W., Taylor, K. & Kosciuch,
K. (2016). Predicting eagle fatalities at wind facilities. J.
Wildl. Manag. 80, 1000–1010.
Bose, A., Duerr, T., Klenke, R.A. & Henle, K. (2020).
Assessing the spatial distribution of avian collision risks at
wind turbine structures in Brandenburg, Germany. Conserv.
Sci. Pract. 2, e199.
Boutron, I., Page, M.J., Higgins, J.P., Altman, D.G., Lundh,
A., Hr
objartsson, A. & Group, on behalf of the C. B. M.
(2019). Considering bias and conflicts of interest among the
included studies. In Cochrane handbook for systematic
reviews of interventions: 177–204. The Cochrane
Collaboration, John Wiley & Sons, Ltd.
Cabrera-Cruz, S.A. & Villegas-Patraca, R. (2016). Response of
migrating raptors to an increasing number of wind farms. J.
Appl. Ecol. 53, 1667–1675.
Campedelli, T., Londi, G., Cutini, S., Sorace, A. &
Florenzano, G.T. (2014). Raptor displacement due to the
construction of a wind farm: preliminary results after the
first 2 years since the construction. Ethol. Ecol. Evol. 26,
376–391.
Carrete, M., Sanchez-Zapata, J.A., Benitez, J.R., Lobon, M.,
Montoya, F. & Donazar, J.A. (2012). Mortality at
14 Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

wind-farms is positively related to large-scale distribution
and aggregation in griffon vultures. Biol. Conserv. 145,
102–108.
Cervantes, F., Martins, M. & Simmons, R.E. (2022).
Population viability assessment of an endangered raptor
using detection/non-detection data reveals susceptibility to
anthropogenic impacts. R. Soc. Open Sci.,9.
Chabot, E. & Slater, S. (2018). Evaluation of wind-energy
survey protocols for migrating eagle detection. Wildl. Soc.
Bull. 42, 587–596.
Conkling, T., Loss, S., Diffendorfer, J., Duerr, A. & Katzner,
T. (2021). Limitations, lack of standardization, and
recommended best practices in studies of renewable energy
effects on birds and bats. Conserv. Biol. 35,64–76.
Crewe, T., Taylor, P., Mackenzie, S., Lepage, D., Aubry, Y.,
Crysler, Z., Finney, G., Francis, C., Guglielmo, C.,
Hamilton, D., Holberton, R., Loring, P., Mitchell, G.,
Norris, R., Paquet, J., Ronconi, R., Smetzer, J., Smith, P.,
Welch, L. & Woodworth, B. (2017). The Motus wildlife
tracking system: a collaborative research network to enhance
the understanding of wildlife movement. Avian Conserv.
Ecol. 18,8.
Dahl, E.L. (2014). Population dynamics in white-tailed eagle at
an on-shore wind farm area in coastal Norway (Doctoral
thesis). Norges teknisk-naturvitenskapelige universitet,
Fakultet for naturvitenskap og teknologi, Institutt for biologi.
Dahl, E.L., Bevanger, K., Nyg

ard, T., Røskaft, E. & Stokke,
B.G. (2012). Reduced breeding success in white-tailed
eagles at Smøla windfarm, western Norway, is caused by
mortality and displacement. Biol. Conserv. 145,79–85.
Desholm, M. (2009). Avian sensitivity to mortality: prioritising
migratory bird species for assessment at proposed wind
farms. J. Environ. Manag. 90, 2672–2679.
Desholm, M., Fox, A., Beasley, P. & Kahlert, J. (2006).
Remote techniques for counting and estimating the number
of bird-wind turbine collisions at sea: a review. Ibis 148,
76–89.
DeVault, T.L., Seamans, T.W., Linnell, K.E., Sparks, D.W. &
Beasley, J.C. (2017). Scavenger removal of bird carcasses at
simulated wind turbines: does carcass type matter?
Ecosphere 8(11).
Dohm, R., Jennelle, C.S., Garvin, J.C. & Drake, D. (2019). A
long-term assessment of raptor displacement at a wind farm.
Front. Ecol. Environ. 17, 433–438.
Dohm, R., Jennelle, C.S., Garvin, J.C. & Drake, D. (2020).
Documented raptor displacement at a wind farm. Front.
Ecol. Environ. 18, 122–123.
Donazar, J.A., Cortes-Avizanda, A., Fargallo, J.A., Margalida,
A., Moleon, M., Morales-Reyes, Z., Moreno-Opo, R.,
Perez-Garcia, J.M., Sanchez-Zapata, J.A., Zuberogoitia, I. &
Serrano, D. (2016). Roles of raptors in a changing world:
from flagships to providers key ecosystem services. Ardeola
63, 181–234.
Douglas, D.J.T., Follestad, A., Langston, R.H.W. &
Pearce-Higgins, J.W. (2012). Modelled sensitivity of avian
collision rate at wind turbines varies with number of hours
of flight activity input data. Ibis 154, 858–861.
Drewitt, A.L. & Langston, R.H.W. (2006). Assessing the
impacts of wind farms on birds. Ibis 148,29–42.
Duriez, O., Pilard, P., Saulnier, N., Boudarel, P. & Besnard, A.
(2022). Windfarm collisions in medium-sized raptors: even
increasing populations can suffer strong demographic
impacts. Anim. Conserv. 26, 264–275.
Evans, J.A. (2013). Future Science. Science 342,44–45.
Farfan, M.A., Duarte, J., Real, R., Munoz, A.R., Fa, J.E. &
Vargas, J.M. (2017). Differential recovery of habitat use by
birds after wind farm installation: a multi-year comparison.
Environ. Impact Assess. Rev. 64,8–15.
Farf
an, M.

A., D
ıaz-Ruiz, F., Duarte, J., Mart
ın-Taboada, A. &
Mu~
noz, A.-R. (2023). Wind farms and griffon vultures:
evidence that under certain conditions history is not-always
turbulent. Glob. Ecol. Conserv. 48, e02728.
Ferguson-Lees, J. & Christie, D.A. (2001). Raptors of the
world. Houghton Mifflin Harcourt.
Fern
andez-Bellon, D. (2020). Limited accessibility and bias in
wildlife-wind energy knowledge: a bilingual systematic
review of a globally distributed bird group. Sci. Total
Environ. 737, 140238.
Fernandez-Bellon, D., Wilson, M.W., Irwin, S. & O’Halloran,
J. (2019). Effects of development of wind energy and
associated changes in land use on bird densities in upland
areas. Conserv. Biol. 33, 413–422.
Ferrer, M., de Lucas, M., Janss, G.F.E., Casado, E., Munoz,
A.R., Bechard, M.J. & Calabuig, C.P. (2012). Weak
relationship between risk assessment studies and recorded
mortality in wind farms. J. Appl. Ecol. 49,38–46.
Ferrer, M., Alloing, A., Baumbush, R. & Morandini, V.
(2022). Significant decline of griffon vulture collision
mortality in wind farms during 13-year of a selective
turbine stopping protocol. Glob. Ecol. Conserv. 38, e02203.
Garcia-Ripolles, C. & Lopez-Lopez, P. (2011). Integrating
effects of supplementary feeding, poisoning, pollutant
ingestion and wind farms of two vulture species in Spain
using a population viability analysis. J. Ornithol. 152, 879–
888.
Garvin, J.C., Jennelle, C.S., Drake, D. & Grodsky, S.M.
(2011). Response of raptors to a windfarm. J. Appl. Ecol.
48, 199–209.
Gottwald, J., Zeidler, R., Friess, N., Ludwig, M., Reudenbach,
C. & Nauss, T. (2019). Introduction of an automatic and
open-source radio-tracking system for small animals.
Methods Ecol. Evol. 10, 2163–2172.
Griffin, A.S., Brown, C., Woodworth, B.K., Ballard, G.-A.,
Blanch, S., Campbell, H.A., Crewe, T.L., Hansbro, P.M.,
Herbert, C.A., Hosking, T., Hoye, B.J., Law, B., Leigh, K.,
Machovsky-Capuska, G.E., Rasmussen, T., McDonald, P.G.,
Roderick, M., Slade, C., Mackenzie, S.A. & Taylor, P.D.
(2020). A large-scale automated radio telemetry network for
monitoring movements of terrestrial wildlife in Australia.
Aust. Zool. 40, 379–391.
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 15
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

Hallingstad, E.C., Rabie, P.A., Telander, A.C., Roppe, J.A. &
Nagy, L.R. (2018). Developing an efficient protocol for
monitoring eagle fatalities at wind energy facilities. PLoS
One. 13, e0208700.
Hernandez-Pliego, J., de Lucas, M., Munoz, A.-R. & Ferrer,
M. (2015). Effects of wind farms on Montagu’s harrier
(Circus pygargus) in southern Spain. Biol. Conserv. 191,
452–458.
Heuck, C., Herrmann, C., Wendt, J., Krone, O., Brandl, R. &
Albrecht, J. (2020). Sex -but not age-biased wind turbine
collision mortality in the white-tailed eagle Haliaeetus
albicilla. J. Ornithol. 161, 753–757.
Hilgerloh, G., Michalik, A. & Raddatz, B. (2011). Autumn
migration of soaring birds through the Gebel El Zeit
important bird area (IBA), Egypt, threatened by wind farm
projects. Bird Conserv. Int. 21, 365–375.
Hull, C.L., Stark, E.M., Peruzzo, S. & Sims, C.C. (2013).
Avian collisions at two wind farms in Tasmania, Australia:
taxonomic and ecological characteristics of colliders versus
non-colliders. NZ J. Zool. 40,47–62.
Hunt, W.G. (2002). Golden eagles in a perilous landscape:
predicting the effects of mitigation for wind turbine blade
strike mortality. Sacramento, CA: Public Interest Energy
Res. Calif. Energy Comm.
Hunt, W.G. & Hunt, T. (2006). The trend of golden eagle
territory occupancy in the vicinity of the Altamont pass
wind resource area: 2005 survey. Boise, Idaho: California
Energy Commission, PIER Energy-Related Environmental
Research.
Hunt, W.G. & Watson, J.W. (2016). Addressing the factors
that juxtapose raptors and wind turbines. J. Raptor Res. 50,
92–96.
Hunt, W.G., Jackman, R.E., Hunt, T.L., Driscoll, D.E. & Culp,
L. (1999). A population study of golden eagles in the
Altamont pass wind resource area: population trend analysis,
1994–1997. NREL/SR-500-26092, 12148.
Hunt, W.G., McClure, C.J.W. & Allison, T.D. (2015). Do
raptors react to ultraviolet light? J. Raptor Res. 49, 342.
Husby, M. & Pearson, M. (2022). Wind farms and power
lines have negative effects on territory occupancy in
Eurasian eagle owls (Bubo bubo). Animals 12.
Huso, M.M.P., Dalthorp, D., Dail, D. & Madsen, L. (2015).
Estimating wind-turbine-caused bird and bat fatality when
zero carcasses are observed. Ecol. Appl. 25, 1213–1225.
Jacobsen, E., Jensen, F. & Blew, J. (2019). Avoidance
behaviour of migrating raptors approaching an offshore
wind farm. In Wind energy and wildlife impacts:43–50.
Cham: Springer.
Johnston, N.N., Bradley, J.E. & Otter, K.A. (2014). Increased
flight altitudes among migrating golden eagles suggest
turbine avoidance at a Rocky Mountain wind installation.
PLoS One. 9, e93030.
Jongejans, E., van der Jeugd, H., Dutch Raptor Group,
Verboom, J., Schotman, A., Buij, R. & Schippers, P. (2020).
Data from: Mortality limits used in wind energy impact
assessment underestimate impacts of wind farms on bird
populations [Data set]. Ecology & Evolution. Zenodo.
https://doi.org/10.5281/zenodo.3760516
Katzner, T.E., Brandes, D., Miller, T., Lanzone, M.,
Maisonneuve, C., Tremblay, J.A., Mulvihill, R. & Merovich,
G.T., Jr. (2012). Topography drives migratory flight altitude
of golden eagles: implications for on-shore wind energy
development. J. Appl. Ecol. 49, 1178–1186.
Katzner, T.E., Bragin, E.A., Bragin, A.E., McGrady, M.,
Miller, T.A. & Bildstein, K.L. (2016). Unusual clockwise
loop migration lengthens travel distances and increases
potential risks for a central Asian, long distance, trans-
equatorial migrant, the red-footed falcon Falco vespertinus.
Bird Study 63, 406–412.
Katzner, T.E., Nelson, D.M., Braham, M.A., Doyle, J.M.,
Fernandez, N.B., Duerr, A.E., Bloom, P.H., Fitzpatrick,
M.C., Miller, T.A., Culver, R.C.E., Braswell, L. &
DeWoody, J.A. (2017). Golden eagle fatalities and the
continental-scale consequences of local wind-energy
generation. Conserv. Biol. 31, 406–415.
Katzner, T.E., Nelson, D.M., Diffendorfer, J.E., Duerr, A.E.,
Campbell, C.J., Leslie, D., Vander Zanden, H.B., Yee, J.L.,
Sur, M., Huso, M.M.P., Braham, M.A., Morrison, M.L.,
Loss, S.R., Poessel, S.A., Conkling, T.J. & Miller, T.A.
(2019). Wind energy: an ecological challenge. Science 366,
1206–1207.
Kikuchi, R. (2008). Adverse impacts of wind power
generation on collision behaviour of birds and anti-predator
behaviour of squirrels. J. Nat. Conserv. 16,44–55.
Kikuchi, D.M., Nakahara, T., Kitamura, W. & Yamaguchi,
N.M. (2019). Estimating potential costs of cumulative
barrier effects on migrating raptors: a case study using
global positioning system tracking in Japan. In Wind energy
and wildlife impacts. Bispo, R., Bernardino, J., Coelho, H.
& Lino Costa, J. (Eds). Cham: Springer. https://doi.org/10.
1007/978-3-030-05520-2_4
Kolar, P.S. (2013). Impacts of wind energy development on
breeding Buteo hawks in the Columbia plateau ecoregion.
Theses Diss, Boise, ID: Boise State Univ.
Kolar, P.S. & Bechard, M.J. (2016). Wind energy, nest
success, and post-fledging survival of Buteo hawks. J.
Wildl. Manag. 80, 1242–1255.
Konno, K., Akasaka, M., Koshida, C., Katayama, N., Osada,
N., Spake, R. & Amano, T. (2020). Ignoring non-English-
language studies may bias ecological meta-analyses. Ecol.
Evol. 10, 6373–6384.
Kumar, Y., Ringenberg, J., Depuru, S.S., Devabhaktuni, V.K.,
Lee, J.W., Nikolaidis, E., Andersen, B. & Afjeh, A. (2016).
Wind energy: trends and enabling technologies. Renew. Sust.
Energ. Rev. 53, 209–224.
Kunz, T.H., Arnett, E.B., Cooper, B.M., Erickson, W.P.,
Larkin, R.P., Mabee, T., Morrison, M.L., Strickland, M.D.
& Szewczak, J.M. (2007). Assessing impacts of wind-
energy development on nocturnally active birds and bats: a
guidance document. J. Wildl. Manag. 71, 2449–2486.
16 Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

Lanzone, M.J., Miller, T.A., Turk, P., Brandes, D., Halverson,
C., Maisonneuve, C., Tremblay, J., Cooper, J., O’Malley,
K., Brooks, R.P. & Katzner, T. (2012). Flight responses by
a migratory soaring raptor to changing meteorological
conditions. Biol. Lett. 8, 710–713.
Law, P.R. & Fuller, M. (2018). Evaluating anthropogenic
landscape alterations as wildlife hazards, with wind farms as
an example. Ecol. Indic. 94, 380–385.
Linder, A.C., Lyhne, H., Laubek, B., Bruhn, D. & Pertoldi, C.
(2022). Quantifying raptors’flight behavior to assess
collision risk and avoidance behavior to wind turbines.
Symmetry 14, 2245.
L
opez-L
opez, P. (2016). Individual-based tracking systems in
ornithology: welcome to the era of big data. Ardeola 63,5–
34.
L
opez-Peinado, A., Lis, A., Perona, A.M. & Lopez-Lopez, P.
(2020). Habitat preferences of the tawny owl (Strix aluco)
in a special conservancy area of eastern Spain. J. Raptor
Res. 54, 402–413.
Loss, S.R., Will, T. & Marra, P.P. (2015). Direct mortality of
birds from anthropogenic causes. Annu. Rev. Ecol. Evol.
Syst. 46,99–120.
de Lucas, M., Janss, G.F.E., Whitfield, D.P. & Ferrer, M.
(2008). Collision fatality of raptors in wind farms does not
depend on raptor abundance. J. Appl. Ecol. 45, 1695–1703.
de Lucas, M., Ferrer, M., Bechard, M.J. & Munoz, A.R.
(2012a). Griffon vulture mortality at wind farms in southern
Spain: distribution of fatalities and active mitigation
measures. Biol. Conserv. 147, 184–189.
de Lucas, M., Ferrer, M. & Janss, G.F.E. (2012b). Using wind
tunnels to predict bird mortality in wind farms: the case of
griffon vultures. PLoS One 7, e48092.
Madders, M. & Whitfield, D.P. (2006). Upland raptors and the
assessment of wind farm impacts. Ibis 148,43–56.
Marques, A.T., Santos, C.D., Hanssen, F., Munoz, A.-R.,
Onrubia, A., Wikelski, M., Moreira, F., Palmeirim, J.M. &
Silva, J.P. (2020). Wind turbines cause functional habitat
loss for migratory soaring birds. J. Anim. Ecol. 89,93–103.
Martin, G.R., Portugal, S.J. & Murn, C.P. (2012). Visual
fields, foraging and collision vulnerability in gyps vultures.
Ibis 154, 626–631.
Martin, B., Perez-Bacalu, C., Onrubia, A., De Lucas, M. &
Ferrer, M. (2018). Impact of wind farms on soaring bird
populations at a migratory bottleneck. Eur. J. Wildl. Res. 64.
Martinez, J.E., Calvo, J.F., Martinez, J.A., Zuberogoitia, I.,
Cerezo, E., Manrique, J., Gomez, G.J., Nevado, J.C.,
Sanchez, M., Sanchez, R., Bayo, J., Pallares, A., Gonzalez,
C., Gomez, J.M., Perez, P. & Motos, J. (2010). Potential
impact of wind farms on territories of large eagles in
southeastern Spain. Biodivers. Conserv. 19, 3757–3767.
Martinez-Abrain, A., Tavecchia, G., Regan, H.M., Jimenez, J.,
Surroca, M. & Oro, D. (2012). Effects of wind farms and
food scarcity on a large scavenging bird species following
an epidemic of bovine spongiform encephalopathy. J. Appl.
Ecol. 49, 109–117.
May, R. (2015). A unifying framework for the underlying
mechanisms of avian avoidance of wind turbines. Biol.
Conserv. 190, 179–187.
May, R., Nygard, T., Dahl, E.L. & Bevanger, K. (2013).
Habitat utilization in white-tailed eagles (Haliaeetus
albicilla) and the displacement impact of the Smola wind-
power plant. Wildl. Soc. Bull. 37,75–83.
May, R., Reitan, O., Bevanger, K., Lorentsen, S.-H. &
Nyg

ard, T. (2015). Mitigating wind-turbine induced avian
mortality: sensory, aerodynamic and cognitive constraints
and options. Renew. Sust. Energ. Rev. 42, 170–181.
May, R., Nygard, T., Falkdalen, U., Astrom, J., Hamre, O. &
Stokke, B.G. (2020). Paint it black: efficacy of increased
wind turbine rotor blade visibility to reduce avian fatalities.
Ecol. Evol. 10, 8927–8935.
May, R., Jackson, C.R., Middel, H., Stokke, B.G. & Verones,
F. (2021). Life-cycle impacts of wind energy development
on bird diversity in Norway. Environ. Impact Assess. Rev.
90, 106635.
McClure, C.J.W., Martinson, L. & Allison, T.D. (2018).
Automated monitoring for birds in flight: proof of concept
with eagles at a wind power facility. Biol. Conserv. 224,
26–33.
McClure, C.J., Dunn, L., McCabe, J.D., Rolek, B.W., Botha,
A., Virani, M.Z., Buij, R. & Katzner, T.E. (2021). Flight
altitudes of raptors in southern Africa highlight vulnerability
of threatened species to wind turbines. Front. Ecol. Evol. 9,
667384.
McClure, C.J.W., Rolek, B.W., Braham, M.A., Miller, T.A.,
Duerr, A.E., McCabe, J.D., Dunn, L. & Katzner, T.E.
(2021b). Eagles enter rotor-swept zones of wind turbines at
rates that vary per turbine. Ecol. Evol. 11, 11267–11274.
McClure, C.J.W., Rolek, B.W., Dunn, L., McCabe, J.D.,
Martinson, L. & Katzner, T. (2021c). Eagle fatalities are
reduced by automated curtailment of wind turbines. J. Appl.
Ecol. 58, 446–452.
Miller, D.A.W. (2012). General methods for sensitivity
analysis of equilibrium dynamics in patch occupancy
models. Ecology 93, 1204–1213.
Miller, T.A., Brooks, R.P., Lanzone, M., Brandes, D., Cooper,
J., O’Malley, K., Maisonneuve, C., Tremblay, J., Duerr, A.
& Katzner, T. (2014). Assessing risk to birds from industrial
wind energy development via paired resource selection
models. Conserv. Biol. 28, 745–755.
Mojica, E.K., Watts, B.D. & Turrin, C.L. (2016). Utilization
probability map for migrating bald eagles in Northeastern
North America: a tool for siting wind energy facilities and
other flight hazards. PLoS One 11, e0157807.
Monti, F., Serroni, P., Rotondaro, F., Sangiuliano, A., Sforzi, A.,
Opramolla, G., Pascazi, A., Spacca, S., La Civita, F. &
Posillico, M. (2023). Survival of a small reintroduced griffon
vulture population in the Apennines: insights from global
positioning system tracking. Avian Biol. Res. 16,3–13.
Murai, Y., Takeda, Y., Kumeno, H. & Okamoto, Y. (2015).
Optical bird detection and species identification for
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 17
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors

prevention of bird strikes in wind farms. In Presented at the
ICOPE 2015 - International Conference on Power
Engineering.
Murgatroyd, M., Bouten, W. & Amar, A. (2021). A predictive
model for improving placement of wind turbines to
minimise collision risk potential for a large soaring raptor.
J. Appl. Ecol. 58, 857–868.
Ng, J.W., Wellicome, T.I., Leston, L.F.V. & Bayne, E.M.
(2022). Home-range habitat selection by ferruginous hawks
in western Canada: implications for wind-energy conflicts.
Avian Conserv. Ecol. 17.
Nishibayashi, N., Kitamura, W. & Yoshizaki, S. (2022).
Comparison of the home ranges of mountain hawk-eagles
during different phases of wind farm construction. Ornithol.
Sci. 21,63–70.
Olea, P.P. & Mateo-Tomas, P. (2014). Living in risky
landscapes: delineating management units in multithreat
environments for effective species conservation. J. Appl.
Ecol. 51,42–52.
Osborn, R.G., Higgins, K.F., Usgaard, R.E., Dieter, C.D. &
Neiger, R.D. (2000). Bird mortality associated with wind
turbines at the Buffalo ridge wind resource area, Minnesota.
Am. Midl. Nat. 143,41–52.
Panuccio, M., Ghafouri, B. & Nourani, E. (2018). Is the slope
between the Alborz mountains and Caspian Sea in northern
Iran a bottleneck for migrating raptors? J. Raptor Res. 52,
530–533.
Pearce-Higgins, J.W., Stephen, L., Langston, R.H.W.,
Bainbridge, I.P. & Bullman, R. (2009). The distribution of
breeding birds around upland wind farms. J. Appl. Ecol. 46,
1323–1331.
Percival, S.M. (2005). Birds and windfarms: what are the real
issues? Br. Birds. 98, 194–204.
Peron, G., Fleming, C.H., Duriez, O., Fluhr, J., Itty, C.,
Lambertucci, S., Safi, K., Shepard, E.L.C. & Calabrese,
J.M. (2017). The energy landscape predicts flight height and
wind turbine collision hazard in three species of large
soaring raptor. J. Appl. Ecol. 54, 1895–1906.
Pescador, M., Gomez Ramirez, J.I. & Peris, S.J. (2019).
Effectiveness of a mitigation measure for the lesser kestrel
(Falco nawnanni) in wind farms in Spain. J. Environ.
Manag. 231, 919–925.
Poessel, S.A., Bragin, E.A., Sharpe, P.B., Garcelon, D.K.,
Bartoszuk, K. & Katzner, T.E. (2018a). Movements and
landscape use of eastern Imperial eagles Aquila heliaca in
Central Asia. Bird Study 65, 208–218.
Poessel, S.A., Brandt, J., Mendenhall, L., Braham, M.A.,
Lanzone, M.J., McGann, A.J. & Katzner, T.E. (2018b).
Flight response to spatial and temporal correlates informs
risk from wind turbines to the California condor. Condor.
120, 330–342.
Reid, T., Kr€
uger, S., Whitfield, D.P. & Amar, A. (2015).
Using spatial analyses of bearded vulture movements in
southern Africa to inform wind turbine placement. J. Appl.
Ecol. 52, 881–892.
Rushworth, I. & Krueger, S. (2014). Wind farms threaten
southern Africa’s cliff-nesting vultures. Ostrich 85,13–23.
Santos, C.D., Marques, A.T. & May, R. (2020). Recovery of
raptors from displacement by wind farms - a response.
Front. Ecol. Environ. 18, 121–122.
Sanz-Aguilar, A., De Pablo, F. & Antonio Donazar, J. (2015).
Age-dependent survival of Island vs. mainland populations
of two avian scavengers: delving into migration costs.
Oecologia 179, 405–414.
Sawin, J.L., Sverrisson, F., Rutovitz, J., Dwyer, S., Teske, S.,
Murdock, H.E., Adib, R. et al. (2018). Renewables 2018 -
Global status report a comprehensive annual overview of
the state of renewable energy advancing the global
renewable energy transition - Highlights of the REN21
renewables 2018 global status report in perspective (No.
978-3-9818911-3-3), France.
Schaub, M. (2012). Spatial distribution of wind turbines is
crucial for the survival of red kite populations. Biol.
Conserv. 155,111–118.
Schekler, I., Nave, T., Shimshoni, I. & Sapir, N. (2023).
Automatic detection of migrating soaring bird flocks using
weather radars by deep learning. Methods Ecol. Evol. 14,
2084–2094.
Schindler, S., Poirazidis, K., Ruiz, C., Scandolara, C.,
C
arcamo, B., Eastham, C. & Catsadorakis, G. (2015). At
the crossroads from Asia to Europe: spring migration of
raptors and black storks in Dadia National Park (Greece). J.
Nat. Hist. 49, 285–300.
Schuster, E., Bulling, L. & Koeppel, J. (2015). Consolidating
the state of knowledge: a Synoptical review of wind
energy’s wildlife effects. Environ. Manag. 56, 300–331.
Sheppard, J.K., McGann, A., Lanzone, M. & Swaisgood, R.R.
(2015). An autonomous GPS geofence alert system to curtail
avian fatalities at wind farms. Anim. Biotelemetry. 3, 43.
Singh, N.J., Moss, E., Hipkiss, T., Ecke, F., Dettki, H.,
Sandstrom, P., Bloom, P., Kidd, J., Thomas, S. & Hornfeldt,
B. (2016). Habitat selection by adult golden eagles Aquila
chrysaetos during the breeding season and implications for
wind farm establishment. Bird Study 63, 233–240.
Skov, H., Desholm, M., Heinanen, S., Kahlert, J.A., Laubek,
B., Jensen, N.E., Zydelis, R. & Jensen, B.P. (2016). Patterns
of migrating soaring migrants indicate attraction to marine
wind farms. Biol. Lett.,12, 12.
Smallwood, K.S. (2013). Comparing bird and bat fatality-rate
estimates among north American wind-energy projects.
Wildl. Soc. Bull. 37,19–33.
Smallwood, K.S. & Karas, B. (2009). Avian and bat fatality
rates at old-generation and repowered wind turbines in
California. J. Wildl. Manag. 73, 1062–1071.
Smallwood, K.S. & Thelander, C. (2008). Bird mortality in
the Altamont pass wind resource area, California. J. Wildl.
Manag. 72, 215–223.
Smallwood, K.S., Thelander, C.G., Morrison, M.L. & Rugge,
L.M. (2007). Burrowing owl mortality in the Altamont pass
wind resource area. J. Wildl. Manag. 71, 1513–1524.
18 Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London.
Review of effects of wind farms on raptors I. Estell
es-Domingo and P. L
opez-L
opez

Smallwood, K.S., Rugge, L. & Morrison, M.L. (2009).
Influence of behavior on bird mortality in wind energy
developments. J. Wildl. Manag. 73, 1082–1098.
Smallwood, K.S., Bell, D.A., Snyder, S.A. & Didonato, J.E.
(2010). Novel scavenger removal trials increase wind
turbine-caused avian fatality estimates. J. Wildl. Manag. 74,
1089–1097.
Ster
ze, J. & Pogacnik, M. (2008). The impacts of wind farms
on animal species. Acta Vet-Beogr. 58, 615–632.
Strandberg, R., Klaassen, R.H.G. & Thorup, K. (2009).
Spatio-temporal distribution of migrating raptors: a
comparison of ringing and satellite tracking. J. Avian Biol.
40, 500–510.
Sur, M., Belthoff, J.R., Bjerre, E.R., Millsap, B.A. & Katzner,
T. (2018). The utility of point count surveys to predict
wildlife interactions with wind energy facilities: an example
focused on golden eagles. Ecol. Indic. 88, 126–133.
Telleria, J. (2009). Wind power plants and the conservation of
birds and bats in Spain: a geographical assessment.
Biodivers. Conserv. 18, 1781–1791.
Thaxter, C.B., Buchanan, G.M., Carr, J., Butchart, S.H.M.,
Newbold, T., Green, R.E., Tobias, J.A., Foden, W.B.,
O’Brien, S. & Pearce-Higgins, J.W. (2017). Bird and bat
species’global vulnerability to collision mortality at wind
farms revealed through a trait-based assessment. Proc. R.
Soc. B Biol. Sci. 284, 20170829.
Therkildsen, O.R., Balsby, T.J.S., Kjeldsen, J.P., Nielsen, R.D.,
Bladt, J. & Fox, A.D. (2021). Changes in flight paths of
large-bodied birds after construction of large terrestrial wind
turbines. J. Environ. Manag. 290.
Vignali, S., Loercher, F., Hegglin, D., Arlettaz, R. &
Braunisch, V. (2022). A predictive flight-altitude model for
avoiding future conflicts between an emblematic raptor and
wind energy development in the Swiss Alps. R. Soc. Open
Sci.,9,2.
Villegas-Patraca, R., Cabrera-Cruz, S.A. & Herrera-Alsina, L.
(2014). Soaring migratory birds avoid wind farm in the
isthmus of Tehuantepec, Southern Mexico. PLoS One 9,
e92462.
Watson, J.W. & Whitfield, P. (2002). A conservation
framework for the Golden eagle (Aquila chrysaetos)in
Scotland. J. Raptor Res. 36,41–49.
Watson, R.T., Kolar, P.S., Ferrer, M., Nyg

ard, T., Johnston, N.,
Hunt, W.G., Smit-Robinson, H.A., Farmer, C.J., Huso, M. &
Katzner, T.E. (2018). Raptor interactions with wind energy:
case studies from around the world. J. Raptor Res. 52,1–18.
Wilson, D., Hulka, S. & Bennun, L. (2022). A review of
raptor carcass persistence trials and the practical
implications for fatality estimation at wind farms. PeerJ. 10.
Wulff, S.J., Butler, M.J. & Ballard, W.B. (2016). Assessment of
diurnal wind turbine collision risk for grassland birds on the
southern Great Plains. J. Fish Wildl. Manag. 7, 129–140.
Supporting information
Additional supporting information may be found online in
the Supporting Information section at the end of the article.
Data S1. Supporting Information.
Animal Conservation  (2024) – ª2024 The Author(s). Animal Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of
London. 19
I. Estell
es-Domingo and P. L
opez-L
opez Review of effects of wind farms on raptors