1st International Bat Research Online Symposium (IBROS):
Towards solving the wind energy-bat conflict

Tuesday, 2nd November 2021
08:45 - 17:30 (CET)

The global expansion of wind energy production represents an, as yet, unsolved green-green dilemma due to habitat degradation caused by the erection of turbines and the risk for bats of colliding with the rotating blades. Effective compensation and mitigation schemes are central for making so-called green energy production by wind turbines ecologically sustainable. We have invited a number of keynote speakers who will report on the wind energy-bat conflict from their country or continent, and present new scientific evidence on how to protect bats efficiently at wind turbines.

The online symposium is aimed at scientists, representatives of authorities, experts and representatives of wind energy companies. The event will be conducted in English.


08:45 - 09:00 Opening of the event
08:00 Opening of the lobby for registered participants
08:45 - 09:00 Christian Voigt (Leibniz Institute for Zoo and Wildlife Research, Germany):
Welcome + housekeeping
09:00 - 11:30 Keynote talks: Perspectives from Europe and Africa
09:00 - 09:30 Fiona Mathews (University of Sussex, UK):
Attraction of bats to wind turbines and its implications for planning policies
09:30 - 10:00 Christian Voigt (Leibniz Institute for Zoo and Wildlife Research, Germany):
Bat-wind turbine interactions studied by GPS tracking of common noctules (Nyctalus noctula)
10:00 - 10:03 Sponsor presentation: EcoObs
10:03 - 10:06 Sponsor presentation: Wildlife Acoustics
10:06 - 10:30 Coffee break
10:30 - 11:00 Christian Kerbiriou (National Museum of Natural History, France):
Challenges of mitigating wind energy impacts on bats
11:00 - 11:30 Kate MacEwan (Western Ecosystems Technology, Inc., US):
Bats and wind energy development in Africa – where are we at in our understanding?
11:30 - 13:15 Short presentations
11:30 - 11:45 Dai Fukui (University of Tokyo, Japan):
Current status of the bat-windfarm conflict in Japan and overview of an ongoing project
11:45 - 12:00 Joe Chun-Chia Huang (Formosa Natural History Information Ltd., Taiwan):
Wings over the oriental ocean: First report of bat activity in offshore wind farm candidate sites in Taiwan
12:00 - 12:15 Antje Seebens-Hoyer (NABU Mecklenburg-Vorpommern, Germany):
Bat migration over the German North and Baltic Sea
12:15 - 13:15 Breakout session: Workshop by Wildlife Acoustics:
Are you SMART about bats? A new detection system for windfarms
Lunch Break
13:15 - 15:45 Keynote talks: Perspectives from North and South America
13:15 - 13:45 Winifred Frick (Bat Conservation International, US):
Why evidence-based solutions are necessary but insufficient to resolve the threat of wind energy to bats in North America
13:45 - 14:15 Erin Baerwald (University of Northern British Columbia, Canada):
Landscape features associated with bat fatalities at wind energy facilities in North America
14:15 - 14:45 Enrico Bernard (Universidade Federal de Pernambuco, Brazil):
Large improvements are needed in the environmental assessment of bats and wind energy in Brazil
14:45 - 15:15 Armando Rodríguez-Durán (Inter American University, Puerto Rico):
Wind energy and bats in the Caribbean Basin: Navigating in the dark
15:15 - 15:18 Sponsor presentation: Titley Scientific
15:18 - 15:45 Coffee break
15:45 - 16:30 Short presentations
15:45 - 16:00 Jonathan Aronson (Camissa Sustainability Consulting, The Netherlands):
Current state of knowledge of wind energy impacts on bats in South Africa
16:00 - 16:15 Camille Leroux (National Museum of Natural History - Auddicé biodiversité, France):
Does wind turbine lighting determine wind turbine effects on habitat use by bats?
16:15 - 16:30 Xavier Puig-Montserrat (Natural Sciences Museum of Granollers, Spain):
Reference values of bat activity for environmental impact assessment
16:30 - 17:00 Poster presentations
16:30 - 16:36 Charlotte Roemer (National Museum of Natural History, France):
Bat migration routes in Europe: An acoustic venture
16:36 - 16:42 Emyo Fujioka (Doshisha University, Japan):
Nightly movement behavior of the birdlike noctule Nyctalus aviator, measured by GPS bio-logging
16:42 - 16:48 Marina Perceval Camps (Natural Science Museum of Granollers, Spain):
Knowledge gaps of the impact on fauna in the global deployment of wind energy
16:48 - 16:54 Sercan Alipek (Goethe University Frankfurt, Germany):
Development of a bat call to background discrimination and bat species classification system based on convolutional neural networks: Performance analysis with measurements from the wind energy test site WINSENT
16:54 - 17:00 Winfried Rampe (Verein Umwelt- und Naturschutz Hochsauerland e.V, Germany):
About bat monitoring to reduce the mortality at wind turbines
17:00 - 17:30 Discussion & Closing of the event
17:00 - 17:30 Discussion
17:30 Closing of the event


Keynote talks

Fiona Mathews (University of Sussex, UK)

Attraction of bats to wind turbines and its implications for planning policies

Fiona Mathews

University of Sussex, UK

Thousands of bats are killed by wind turbines annually. However, efforts to reduce the impacts by careful positioning of wind farms in the landscape have been less effective than hoped. This is partly because habitat suitability mapping is a course tool for identifying sites of highest risk, but also because bat behaviour may differ pre- and post-construction.  In the UK, we assessed bat activity at paired turbine and control locations at 23 wind farms. The research focussed on Pipistrellus species, which were by far the most abundant bats recorded at these sites. P. pipistrellus activity was 37% higher at turbines than at control locations, whereas P. pygmaeus activity was consistent with no attraction or repulsion by turbines. Given that more than 50% of bat fatalities in Europe are P. pipistrellus, these findings help explain why Environmental Impact Assessments conducted before the installation of turbines are poor predictors of actual fatality rates. In future, developments should not only avoid sites considered to be of high bat activity pre-construction, but there should be post-construction monitoring and operational mitigation, since the presence of turbines alters bat activity.

Christian Voigt (Leibniz Institute for Zoo and Wildlife Research, Germany)

Bat-wind turbine interactions studied by GPS tracking of common noctules (Nyctalus noctula)

Christian C. Voigt

Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin

Wind turbines are being erected on an increasing scale worldwide, with only minor efforts to mitigate the problem of bat fatalities and a poor understanding about factors driving bat mortality at turbines. Globally, there is by and large no clear commitment from governments to protect bats at wind turbines. Germany, with a total of about 30,000 onshore turbines (as of 2020), ranks third in the world in terms of the total number of turbines. Although carcasses were documented below wind turbines before the turn of the century, mitigation schemes such as curtailment were not implemented in Germany until around 2008. At that time, about 15,000 wind turbines were already in operation. These turbines have generated and still generate enormous losses of bats over the course of their guaranteed operation time of 20+ years. As of 2019, it is estimated that only 25% of onshore wind turbines in Germany operate under a mitigation scheme. In a recent study, we documented that mostly female and juvenile bats are killed at turbines. Indeed, juveniles were more likely to get killed by wind turbines than expected based on their frequency in the life population, highlighting that juveniles are particularly vulnerable at turbines. Since 2008, curtailments of turbine operation have been increasingly implemented, but efforts which place turbines in sensitive areas, such as forests or waterbodies, are also increasing. In Germany, Nyctalus noctula, the common noctule bat, has one of the highest fatality rates with turbines. Notably, populations of common noctules are declining in Germany. To better undstand, wind turbine-bat interactions, we analysed the spatial tracks of >70 bats equipped with GPS loggers at a coastal area dominated by farmland and at an inland area dominated by managed forests. We observed a highly variable response (attracted, neutral, avoidant) of common noctules towards turbines, with no sex differences. Bats were more likely to be encountered at wind turbines when turbines were located near foraging areas such as waterbodies and farmhouses. At our coastal site, the likelihood of common noctules being present at large turbines increased with proximity to roosts. At our inland site, the likelihood of common noctules being present at turbines was high when these were large or located in the periphery of wind parks. The current practice of erecting ever larger wind turbines in sensitive areas, i.e. close to daytime roosts and foraging areas, seems to be in conflict with the goal of protecting bats from colliding with wind turbines.

Christian Kerbiriou (National Museum of Natural History, France)

Challenges of mitigating wind energy impacts on bats

Christian Kerbiriou, Kévin Barré, Charlotte Roemer, Jeremy Froidevaux, Camille Leroux, Alejandro Sotillo, Yves Bas, Isabelle Le Viol, Julie Marmet, Jean François Julien

To limit the negative effects of project development on biodiversity, many countries adopt a mitigation hierarchy (avoidance, reduction and offsetting). Mitigation is intended to achieve a no net loss of biodiversity requiring a so-called ecological equivalence between biodiversity losses and biodiversity gains. Here we re-visited the different step of mitigation as part of the wind farm settlement and functioning, considering their impacts on bats. We focused on the limitations -mainly from the French case- and discussed solutions.

Despite some guidelines about the way to carry out environmental impact assessment and post-construction monitoring studies, we highlight the need to (i) improve data and metadata accessibility, and (ii) homogenize monitoring methods. Secondly, we underline the limits of the case-by-case approach advocated until now in France to efficiently mitigate impacts. Thirdly, we have examined how avoidance is currently addressed and how large-scale species distribution modelling could help a wind planning more biodiversity-friendly, raising questions about consideration scales and needed/available data. Fourthly, we investigated how reductions measures are so far implemented and documented. Finally, we sought to find how offset measures were implemented to compensate residual impacts and we are investigating their limits considering the maximum possible growth rate of bats.

We conclude that first of all, the avoidance is the key point to reconciling wind energy production and bats conservation.

Kate MacEwan (Western Ecosystems Technology, Inc. (WEST), US; before: Inkululeko Wildlife Services, South Africa)

Bats and wind energy development in Africa – where are we at in our understanding?

Kate L. MacEwan1, Caroline A. Lötter2,3, Eleanor J. Richardson3

1 Western EcoSystems Technology, Inc. 415 West 17th Street, Suite 200 Cheyenne, Wyoming 82001, US
2 Inkululeko Wildlife Services (Pty) Ltd. 710 Penge Street, Faerie Glen, Pretoria, Gauteng, 0043, South Africa
3 South African Bat Assessment Association, 52 Bowen Ave, Glenmore, Durban, 4001, South Africa

Since the late 1900s, wind energy has been produced on the African continent, starting in the north in countries like Egypt and Morocco, with the largest wind energy facility (365 turbines) on the continent going live in Kenya in 2019, and several projects having been developed further south since the early 2000s. In South Africa, it has been 14 years since the first pilot wind farm was commissioned, and there are well over 40 wind farms in various stages of development. Over 3.5 GW (24%) of the approximately 14.4 GW of wind energy capacity planned for South Africa by the year 2030 has already been commissioned. Across the continent, the wind energy capacity is already contributing approximately 20 GW to the electricity grid, and it is estimated to be at over 50 GW by 2025. However, despite decades of wind power in Africa, we understand very little about the interactions between African bats and wind turbines. Individual, site-specific operational monitoring studies (mostly unpublished) have been completed but, until now, there has been no coordinated collation of bat fatality data. We present here bat fatality data from operational wind farms in South Africa, and where available, bat fatality information from other African countries. We describe how lessons learned from South Africa and Global North countries, could inform the impact of wind turbines on bats in Africa, and lead to a more proactive approach to fatality minimization and adaptive management, whilst recognising the unique challenges and opportunities in different regions of Africa.

Winifred Frick (Bat Conservation International & University of California, US)

Why evidence-based solutions are necessary but insufficient to resolve the threat of wind energy to bats in North America

Winifred F. Frick

Bat Conservation International, 500 N Capitol of Texas Hwy, Austin, Texas, 78746, USA
Ecology and Evolutionary Biology, University of California, Santa Cruz, California 95060 USA

Mortality of bats at wind energy facilities has been recognized as a potential threat to bat populations for nearly two decades. Since the early 2000s, researchers have worked to identify which species are most at risk, to better characterize the spatial and temporal conditions associated with high mortality events, and to understand how, why, and when bats interact with turbines to better assess collision risk. Numerous replicated experimentally designed studies have measured the efficacy of turbine operational strategies to lower bat fatality rates in various contexts since the mid 2000s. Operational curtailment, the strategy that increases the wind speed at which turbine blades spin to generate energy, has now been widely shown to be effective at reducing bat fatalities in North America. A recent meta-analysis estimates that across different wind energy facilities and years, a 5.0 m/s cut-in speed reduces total bat fatalities by an average of 62% per year (54-69% CI) in North America. Concurrent with the evidence that curtailment works to reduce bat fatalities, modelling efforts have quantified the population-level risk to the hoary bat (Lasiurus cinereus), a long-distance migratory species that accounts for over a third of observed fatalities at wind energy facilities in North America. Modelling results indicate that current levels of wind energy build-out in the United States and Canada may have already caused substantial declines of hoary bats in North America. Risk of future decline and extinction may still be mediated with rapid adoption of measures to reduce bat fatalities by roughly half, a level achievable by curtailing turbines at lower wind speeds. Despite strong empirical evidence that curtailment reduces bat fatalities, there has been little incentive for wind industry to voluntarily adopt curtailment practices given that the practice reduces power generation and thus profit. Creative policy solutions that either impose regulatory measures or provide economic incentives are urgently needed to enable the wind energy industry to contribute renewable energy without negative impacts to biodiversity.

Erin Baerwald (University of Northern British Columbia, Canada)

Landscape features associated with bat fatalities at wind energy facilities in North America

Erin F. Baerwald

Department of Ecosystem Science and Management, University of Northern British Columbia, Prince George, BC, V2N 4Z9, Canada

Currently, fatalities at wind energy facilities are one of the greatest known sources of mortality for migratory bats in North America. Between 840,000 and 1.7 million bats were killed by wind turbines in the U.S. and Canada from 2000-2011 but fatalities across North America increase by several hundred thousand annually. Of these fatalities, approximately 72% are of three species of migratory tree-roosting bats: hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans). Recent analyses suggest that fatalities at wind energy facilities are negatively affecting populations of hoary bat and these three species are being considered for listing in Canada. To reduce the impacts of wind energy on bat populations, developers and operators can locate projects in “low fatality risk” areas, but this is challenging because habitat use by migratory tree-roosting species of bat is not well-understood. Intuitively, high-risk areas are within spaces that provide high quality habitat for bats (i.e., places with lots of trees and water) and/or concentrate migrating bats (e.g. riparian corridors or ridgelines), but these spaces are not well-defined. However, modelling based on fatality data og migratory tree-roosting bats from >50 wind energy facilities in Ontario, Canada suggest that fatality risk is correlated with habitat features such as distance to forest and proportion of water, cropland, and urban areas. The data also suggest that fatality rates are correlated more with habitat surrounding a facility (i.e. within a 25 km radius) than within a facility (i.e. within a 1 km or 5 km radius). Landscape features associated with increased fatality rates vary among species however, highlighting the need for species-specific management plans.

Enrico Bernard (Universidade Federal de Pernambuco, Brazil)

Large improvements are needed in the environmental assessment of bats and wind energy in Brazil

Enrico Bernard

Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Brazil

As of August 2021, Brazil has 726 wind farms and ~8,500 turbines producing 19 GW, setting the country as the 8th largest wind energy producer in the world. Wind power installed in the country will reach 25.5 GW by 2024 with an estimated investment of U$ 1.2 billion per year. Although important and necessary as an energy source, the environmental aspect of the wind energy production in Brazil needs improvements. Despite evidence of bat mortality in wind farms in Brazil, the knowledge about the impacts of wind turbines on bats in the country is still poor given the number of wind farms in operation and the magnitude of investments already made. Wind farms´ locations overlaps with potentially bats species-rich – but poorly studied – areas, stressing the need for correct environmental assessments. Regulations for the licensing of wind farms in Brazil are mostly state-determined, but heterogeneous, superficial and incomplete, especially for the assessment of impacts on bats. Few states require a detailed environmental impact assessment, with some accepting simple literature review data. There is an increase in the use of echolocation calls for bat species identification, but the frequent use of software for the unsupervised automatic species identification is producing questionable results on species richness and activity at the parks. The search for bat carcasses is poorly conducted, at unrealistic time intervals and without calibration for carcass removal, resulting in biased information on real bat mortality. Overall, the data produced during such assessments is kept private, with a lack of transparency in the process. Long-term site-specific monitoring must be mandatory, avoiding generalizations for environmental licensing purposes. Brazil is probably one of the most competitive countries in the world when it comes to renewable energies, but in order to be considered really green, the wind energy sector in Brazil must adopt higher environmental standards. In this process, environmental agencies must be seen as key stakeholders for a better regulatory system, complete and detailed environmental assessments are very necessary and, facing the booming of ESG standards, companies need to present concrete commitments to reduce the negative effects of their activities on bats.

Armando Rodríguez-Durán (Inter American University, Puerto Rico)

Wind Energy and Bats in the Caribbean Basin: Navigating in the Dark

Armando Rodríguez-Durán

Universidad Interamericana, Bayamón Puerto Rico

The 21st century’s increasing cost of fossil fuels and greater awareness of climate change catapulted the interest in renewable sources of energy. In 2008, the Caribbean Sustainable Energy Program was established with the assistance of the Organization of American States (OAS) and funded by the European Union. An OAS study in 2011 called Energy Policy and Sector Analysis in the Caribbean underlined the opportunities for renewable energy in some of the Lesser Antilles. The implementation of wind-energy projects in the region has been limited by low wind speeds and difficulties integrating renewable energy into existing energy grids., and promoted by exceedingly high cost of fossil fuels energy. Nevertheless, wind parks continue to develop throughout the region. Although renewable energy is a positive development, secretiveness in the analyses and lack of publication of the environmental assessments is a major problem in the region. In most jurisdictions, the companies managing the facilities oversee evaluating and reporting the environmental assessments to government agencies, and both sequester the information from the public. Based on data from Puerto Rico, tropical Mexico, and the Dominican Republic, it is evident that many bat species in the region are impacted by wind turbines, and understory foragers, some with very small foraging areas, are unexpected but common fatalities. Placing bat fatalities from wind parks in context remains a problem, because population data is lacking for virtually every species. This may be partially remedied through comparisons of fatalities at wind parks and other natural and anthropogenic agents causing bat deaths. Unlike temperate areas, year-round bat activity in the Neotropic complicates implementing typical mitigation strategies, although local studies suggest differences in the impact of turbines based on location. This information can only be verified with independent research, currently been limited by governments and investors. On at least some islands, greater reliance on photovoltaic energy seems to be occurring. The difficulties and potential approaches within the Caribbean basin are further described and analysed.



If you would like to participate in the symposium, please register at:

Regular registration fee: 60 Euro
Reduced registration fee: 40 Euro*

*The reduced rate applies to participants resident in and affiliated with organisations of non-high-income countries (see World Bank classification) and for students and NGO employees of any country. For verification, please send us an appropriate proof by email to batsymposium@izw-berlin.de.

Registration is open until 31st October 2021 midnight CET.

Abstract submission

The deadline for abstract submission has passed (15th September 2021).

All abstracts sent in by 15th September 2021 have been reviewed by the scientific committee. Authors have received notification, confirming whether their abstracts(s) have been accepted for presentation.

Event format & technical details

The online symposum will be delivered remotely with live lectures in Central European Time.

We will be using the video conferencing tool 'Webex meetings'. You will need a stable internet connection for your participation in our symposium.

We highly suggest using a laptop/PC instead of a smart device to best follow along. During the symposium, you will have the opportunity to ask questions and participate in the live discussion. For good audio transmission, we recommend the use of a headset to reduce background noise. If you do not have a microphone/headset, you may as well ask questions via the chat option.

Registered participants will receive the access link to the symposium a few days prior to the event.

In addition, the symposium will be recorded and will be available for registered participants for one week afterwards, yet without the opportunity of asking questions to the presenting authors.

Cancellation policy

If you have to cancel your registration, please send an email to batsymposium@izw-berlin.de. Please note that your cancellation is only valid after you received a confirmation of acceptance from us.

In case of cancellations until 31st October 2021, 80% of the registration fees will be refunded. After 31st October, no refund is possible.


We wish to thank the following supporters of the symposium:

We would be delighted to welcome also your company as sponsor of the 1st International Bat Research Online Symposium! Please have a look at our sponsoring opportunities and do not hesitate to contact us for further information. Any kind of sponsoring including your own ideas is welcome.


For organisational questions:

Josepha Prügel
Conference organisation/Leibniz-IZW Academy
Tel: +49(0)30 5168-127
E-Mail: batsymposium@izw-berlin.de

For topic-related questions:

PD Dr. Christian Voigt
Head of Department
Department of Evolutionary Ecology
Tel: +49(0)30 5168-511
E-Mail: voigt@izw-berlin.de


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