Wildlife and Wind Farms: Conflicts and Solutions Book Review

Wildlife and Wind Farms: Conflicts and Solutions
Book Review by Merlin Tuttle
1/8/18

 

Wildlife and Wind Farms, Conflicts and Solutions, Volume 2, provides a summary of current conflicts and solutions involving the rapid growth of wind farms and their impacts on wildlife. Chapters by leading experts cover topics from turbine siting and mortality monitoring to, statistical evaluations and mitigation.

This is the second of two volumes, both edited by M.R. Perrow. They are thorough and authoritative, an important resource for professionals concerned with wind energy impacts on wildlife. Unfortunately, this is a complex subject, and industry has been slow to adopt many of the remedies reported. Issues for birds and bats differ significantly and typically require different solutions. This review emphasizes those involving bats.

Ridgetop turbines in West Virginia.

Early investigations often failed to account for searcher detectability or scavenger removal rates when calculating wildlife fatalities at wind farms. Such problems were exacerbated by long intervals between searches, during which most corpses were removed by scavengers or arthropods. Small corpses can virtually disappear to human view in even a few inches of vegetation, and most of a night’s kill can be removed by scavengers within hours, depending on local circumstances. Trained dogs have performed far better than humans in searching for kills, but few are used. Fatality detection is complicated and often debated.

 

The impact of scavenger removal is difficult to accurately document. Depending on local scavenger faunas, removal rates can vary greatly. Scavengers may also take time to discover a new food source, causing removal rates to change from week to week or year to year.

 

A turbine-killed hoary bat in West Virginia is nearly invisible even though it has fallen in plain sight.
The same bat circled in red.

Especially in the case of bats, no one knows how many may be permanently injured without detection. It is generally agreed that, early morning searches, are best for detecting bat fatalities prior to scavenger removal, but how often should these searches be conducted, and how can they avoid biases?  Calculations of scavenger removal rates can be affected in many ways. What if scavengers learn to follow human scent trails to birds or bats intentionally placed as surrogates to measure scavenger removal? Also, how can we be sure that surrogate corpses are as attractive as fresh kills? Most surrogates are frozen prior to use. By becoming less attractive with age, scavenger removal could be significantly underestimated.

Statistical adjustments, predictive models, and invaluable insights to the most apparent biases are provided in this publication. However, some are extremely difficult to document. It is still impossible to accurately predict population-level impacts. Even if all other variables were accurately measured, knowledge of actual population size of impacted species rarely, if ever exists. As noted, estimates often fall short of reality, and losses may already be unsustainable in many cases.

 

The chapter on mitigating bat collisions is thorough and enlightening. It reports the apparent futility of predicting bat risks based on pre-construction sampling because turbines appear to attract bats.

 

Ed Arnett searching for bats beneath ridgetop turbines in Pennsylvania. Such terrain is impossile to accurately search without the assistance of a trained dog. However, dogs are seldom used, potentially leading to significant underestimation of bat fatality.

Operational mitigation strategies that could significantly reduce bat mortality were reported as early as 2011. By slightly raising turbine cut-in speeds (the wind speeds at which turbines are permitted to spin for power production) above those set by manufacturers, bat mortality reductions of 50 to 93% are documented in this publication. By 2013, a German study of multiple sites, in different geographic regions, reported fatality reduction of 83% by including algorithms, such as season, time, and temperature.

 

 

 

Due to non-disclosure by power companies, few studies have reported amounts of power lost through such mitigation, but available evidence suggests less than 1%. Unfortunately, few companies, especially outside of Europe, have been willing to incorporate even these simple operational changes.

 

The possible use of acoustic deterrents has long been considered as a means of reducing bat mortality. However, the high frequency signals required for bats attenuate rapidly in air, making them ineffective in covering the large areas required to protect bats at wind turbines. By strategic placement of multiple transmitters on turbines, one study reduced mortality by 64%, but no ultrasonic deterrents are yet available for affordable commercial use. Changing turbine color to reduce attractiveness to insect prey, and use of electromagnetic signals have been proposed but appear unlikely to prove adequate.

Jessica Kerns examines hoary, red, and tri-colored bats, the most frequently killed species on this West Virginia ridge top. A 2004 study conservatively estimated that this 44-turbine wind farm killed between 1,300 and 2,000 bats in a six-week period. Yet, fatality monitoring was discontinued, and no remedial action was taken.

Threshold numbers of bat fatalities, allowed prior to required mitigation, are frequently negotiated as part of the permitting process. However, in my experience in North America they are commonly exceeded with minimal or no remedial action taken.

 

Protection of key habitat, such as hibernation caves, may be useful for endangered species like Indiana myotis (Myotis sodalis), that seldom have been killed by turbines, but this is ineffective for migratory tree-dwelling species such as hoary (Lasiurus cinereus) and red (L. borealis) bats. Despite the absence of population estimates, trends can be regionally monitored at diverse locations not associated with wind farms. Mitigation planning should support systematic, standardized monitoring for such trends. These should be considered in future planning.

Brian Cooper using radar to monitror bat activity near ridgetp turbines in West Virginia.

 

In reviewing current policies, I see a need for far more attention being paid to frequent fatalities of originally abundant species, rather than focusing almost exclusively on only occasionally killed endangered species. We cannot afford to ignore loss of still abundant bats like the Brazilian free-tailed bat (Tadarida brasiliensis), that play key ecological roles, not to mention their invaluable benefits to agriculture. This species already faces thousands of turbines, and is one of the most vulnerable. Yet, there is no reliable long-term monitoring, either of fatality or population trends.

 

Major advances in methodology for reducing threats to bats are reported in this publication. Yet, as one of the pioneers in the search for solutions, I’m deeply disappointed to see how little implementation has occurred thus far. Scientists have made important discoveries. Nevertheless, already proven methods for mortality reduction far too often have been ignored by regulators and industry. Standardized regulations are urgently needed at national and international levels.

Jason Horn and Teresa Labriola, using three thermal imaging scopes trained on a single wind turbine to document bat interactions with turbines in West Virginia.

 

The current North American goal of reducing bat fatalities by 50% is inadequate. Without limiting the number of turbines that can be permitted, such goals offer unrealistic solutions, even if attained.

Though some companies should be applauded for their special efforts, there are few incentives for investing in wildlife. Many of the largest companies still ruthlessly ignore wildlife. However, by providing token financial support for solution-finding research, they lull an environmentally concerned public into complacency.

 

In my opinion, far more progress could be made if a fair-minded rating system were organized collaboratively by concerned industry and environmental representatives. Companies could be ranked according to their wildlife policies (i.e. cooperation in solution finding and the extent to which existing mitigation knowledge is implemented). They needn’t be perfect to rate higher than unconcerned competitors. Such information could be shared with green energy investment advisors, providing potentially strong incentives.

Get the book HERE!

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New Publication in Defense of Bats

Read Merlin’s article, Give Bats a Break, in the Spring 2017 edition of Issues in Science and Technology. This report is based on Merlin’s review of thousands of scientific papers and popular media stories. And it is the first to expose how sensational speculation is fostering bad science in a self-perpetuating cycle of misdirected public health funding that threatens the future of bats. This is an issue that we cannot ignore.

 

Chinese translation available HERE!

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Praise for Speaking Up for Neglected Bats – BAT FLASH

Praise for Speaking Up for Neglected Bats
By Merlin Tuttle
3/17/17

Many thanks to Anthropocene for their timely alert, Wind energy is tough on bats—but it doesn’t have to be that way, by Brandon Keim in their March 15, 2017 issue.

Over the past decade a growing number of peer-reviewed research publications have reported likely-to-be-unsustainable bat kills at wind turbines, also reporting that kills could be reduced by 44-90% by slightly delaying turbine cut-in speeds (the wind speeds at which turbines are activated to begin rotating to produce energy) during the bats’ fall migration.

Merlin Tuttle and Jessica Kern examine bats killed by wind turbines in West Virginia, where Merlin led early efforts to minimize bat kills.

The best available calculations indicate that by implementing these changes, annual power output would be reduced by less than 1%. Yet only a few companies have acted on even these economically feasible recommendations, despite repeated warnings that whole species could be threatened with extinction without prompt action. Keim raises the obvious question, “how people already know so much about solving the problem, yet do so little.” The answer seems obvious—Too many people still don’t know, and too many of us who do have remained silent for too long.

Please take a moment to thank author, Brandon Keim, and the editorial staff at Anthropocene for reminding readers that alarming and growing numbers of ecologically essential bats are being killed needlessly by carelessly operated wind turbines.

TAKE ACTION!

  • Choose any or all means of contact to reach out and send thanks in your own words.
    • Send a Contact Form to Anthropocene Magazine. Be sure to include the article, author and editors by name when you thank them for their much needed reporting on bats.
      • Lindsey Doermann, Founder, Senior Editor, Anthropocene Magazine
      • Kathryn Kohm, Founder, Editor-in-Chief, Anthropocene Magazine
      • Brandon Keim, author
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A hoary bat (Lasiurus cinereus) in Texas. These bats are long-distance migrators, some traveling all the way from Canada to Mexico and back each fall and spring. Large numbers are now being killed needlessly by careless production of wind energy.

 

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Book Review: Conservation and Ecology of Pennsylvania’s Bats

Book Review: Conservation and Ecology of Pennsylvania’s Bats
By Merlin Tuttle
3/16/17

Cal Butchkoski removing a big brown bat from a mist net during a Pennsylvania workshop.

Conservation and Ecology of Pennsylvania’s Bats, edited by C.M. Butchkoski, D.M. Reeder, G.G. Turner, and H.P. Whidden. 2017, is a publication of the Pennsylvania Academy of Science. Twenty-eight contributors cover a wide variety of conservation-relevant topics. It summarizes the key ecological and economic roles of bats and traces the history of bat research and conservation efforts in Pennsylvania, which has one of America’s finest records of conserving bats.

A Wind Energy Voluntary Cooperation Agreement is reported to have gained beneficial results. However, the environmental review process does not cover most of the state’s species. And at least one of the state’s largest companies has refused to participate. The potentially serious, yet inadequately documented wind energy impacts on bats remain as unresolved threats. (more…)

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