--- Bat and Avian Species ---

When discussing the risks that wind turbines can pose for wildlife, it is necessary to access impacts on bat and (avian) species.  Because turbines stand so tall, flying species are the only ones that experience any significant impacts on their habitats.  Turbines can affect these species in a variety of ways, including causing direct collisions with turbine blades, disruption of migratory patterns, or injuries from the altered wind and air pressures.

 Not all of these alterations will result in fatalities.  However, any injury could be detrimental or an individual or a population.  Furthermore, threatened and endangered species are of a special concern, because even small increases in mortality can put these species at increased risk of eradication.  Due to the high concern for these species, a list of them will be provided in Section V. 

Variables such as flight altitude and migration patterns play a huge role in influencing the possible impacts on bat and avian species.  Some species may be more likely to see mortality rates rise because of wind turbines simply because they use a specific area of air space more than other species.  Such variables are common to both bat and avian species.

Special concern has already been given to bat species due to the fact that their numbers are already experiencing sharp declines in light of the emerging disease, white nose syndrome.  This, as well as the bat’s natural weakness to inclement weather, put it at especial risk from the presence of wind turbines.  However, the extent of this influence is still debated amongst different groups and experts.  

Our discussion of the impacts on bat and avian species will proceed in the following format:

I.               Mortality Rates:  Cumulative Estimates on the Impacts to Bat and Avian Species

II.             The Final Report on Bat and Avian Studies (Supplementary Environmental Impact Statement)

III.           Wind Energy Guidelines:  Fish and Wildlife Service

IV.            Interactions with Bat and Avian Species:  Turbine and Wildlife Relationships

V.              Species of Special Concern in the Cape Vincent Area

VI.            Avoidance:  Methods to Reduce Risk

Mortality Rates

I.   Mortality Rates:  Cumulative Estimates on the Impacts to Bat and Avian Species

As part of the Supplementary Environmental Impact Statement prepared for St. Lawrence Wind Power LLC, West Inc used cumulative averages of bat and bird mortality rates across five different wind farms in New York State.  All five are local to the North Country and are within relatively close proximity to the St. Lawrence Wind Farm. 

The estimates for the St. Lawrence Wind Farm’s 53 turbines are summarized below.  We will first discuss the estimates for bats, followed by the estimates for avian species.

Bat Species

Estimates are based upon the National Wind Coordinating Collaborative (NWCC) 2004 National average of 3.4 bat fatalities per turbine per year (fatalities/turbine/year).  The second estimates are based on the NWCC 2004 Eastern average, which is 46.3 bats/turbine/year.

Total fatalities for NWCC 2004 National average:  180  fatalities/turbine/year
Total fatalities for NWCC 2004 Eastern average:  2,454  fatalities/turbine/year

To gain a better idea, the post-construction observations of bat mortality rates at Maple Ridge Wind Farm were used to further estimation.  The minimum was expressed as 15.2 bats/turbine/year, and the maximum as 24.5 bats/turbine/year.  These numbers were gained by observing fatalities between June and November 2006. 

Total fatalities using Wind Ridge Wind Farm observations:  806 – 1299  fatalities/turbine/year

Avian Species

The NWCC 2004 National estimates for avian fatalities were expressed as 2.3 birds/turbine/year.  The NWCC 2004 Eastern estimates were expressed as 4.3 birds/turbine/year.  Again, the Maple Ridge Wind Farm was used as a post-construction reference.  Observations between June and November 2006 recorded between 3.1 to 9.6 birds/turbine/year. 

Total fatalities for NWCC 2004 National average:  122 
Total fatalities for NWCC 2004 Eastern average:  228 
Total fatalities using Wind Ridge Farm observations:  164 – 509 




References
Tetra Tech E.C. Inc. et al. (2009, March 25).  Supplemental Environmental Impact Statement for Proposed St. Lawrence Windpower Project.  Retrieved from: http://stlawrencewind.com/SEIS/SectionsPDF/Tables/Table_4_3_EstimatedCumulative.pdf

Tetra Tech E.C. Inc. et al. (2009, March 25).  Supplemental Environmental Impact Statement for Proposed St. Lawrence Windpower Project.  Retrieved from: 
http://stlawrencewind.com/SEIS/SectionsPDF/Tables/Table_4_2_EstimatedCumulative.pdf

Bat and Avian Studies

II.   The Final Report on Bat and Avian Studies (Supplementary Environmental Impact Statement)

Within the Supplementary Environmental Impact Statement (SEIS) is the Draft Final Report on Bat and Avian Studies for the Proposed St. Lawrence Windpower Project.  It should be noted that the Draft Final Report was chosen for our discussion because the Final Environmental Impact Study does not include a comprehensive report concerning bat and avian species as a whole.  This study (again conducted by West Inc and prepared for the St. Lawrence Windpower, LLC) was broken up into the following subtopics:  Nocturnal Marine Radar Surveys; Raptor Migration Surveys; Breeding Bird Surveys; Nocturnal AnaBat Surveys; and Waterfowl and Winter Raptor Surveys.  Our discussion of this study will follow the order that is used in the SEIS. 

These preconstruction studies used a variety of methods to record data including fixed point and point count surveys for avian species, and the AnaBat sampling method for bats.  Studies were conducted during spring and fall migration periods, as well as throughout the year.  Each study has a unique set of methods that will be elaborated upon within each subsection.

A.  Nocturnal Marine Radar Surveys

The goal of the Nocturnal Marine Radar Survey was to assess the usage of the proposed wind farm site as a migratory path.  Furthermore, this data was compared to other sites in the surrounding area to evaluate whether or not the Cape Vincent area is a preferred migratory path.  If migratory usage was found to exceed that of other sites, it could be argued that the St. Lawrence Wind Farm would be an obstacle for migrating birds. 

A single X-band marine radar unit was used for the survey, as it has been successfully monitored nocturnal migration in the past.  Radar was used so that flight direction, passage rates, and flight altitude could be analyzed.  The study was conducted in both the fall and spring migration periods.  The fall migration period is defined as the 15^th of August to the 15^th of October.  A full explanation of the methods used in this survey is provided on pages 7 and 8 of the Draft Final Report regarding Avian and Bat Studies for the Proposed St. Lawrence Windpower Project. 

1.     Flight Direction

From the survey, a trend was found that showed birds migrating in a Southwestern direction for the Fall and in a Northeastern direction for the Spring.  This could be attributed to that fact that most birds tend to follow the shoreline of Lake Ontario rather than fly across it in a linear fashion. 

2.     Passage Rates

Assessing the passage rates of bird species provides an idea on how many individuals are using the area at once, and at what frequency.  Analyzing such data allows researchers to assess how often an area experiences bird passage.  To avoid errors in data, the survey team used alternative frequencies to rule out air-clutter and rain-clutter variables from the passage rates.  This was done to avoid inflating the results.  The survey on passage rates was conducted in both a horizontal and vertical manner, so as to decrease the margin of error.  The results are expressed as the mean amount of targets per kilometer per hour (targets/km/hour).  The +/- symbol denotes the standard deviation, which explains that the actual results could deviate a certain amount from the mean.  The results are summarized below:

Fall Horizontal survey:  345.8  +/-  13.3  targets/km/hour Fall Vertical survey:  346.2  +/- 17.2  targets/km/hour

Spring Horizontal survey:  166.2  +/-  8.8  targets/km/hour Spring Vertical survey:  191  +/-  9.4  targets/km/hour

3.     Flight Altitude

The flight altitude survey looked at whether or not the birds that used the Cape Vincent area would fly in risk-zone of the wind turbines.  The risk-zone is defined as below 125 meters, which is roughly the height modern wind turbines.  This is the area where collisions are likely to occur.  Again, radar was used to collect this data and is separated between the fall and spring migration surveys.

For the fall, the mean flight altitude was 490.4  +/-  1.7 m, with a sample population of 30,749 individuals.  The highest percentage of individuals had flight altitudes between 201 – 300 m.  Of the total sampling population, 7.7% of all individuals sampled had flight altitudes below 125 m, which put them within the risk zone.  However, it was found that the middle 50% of the sampling distribution had flight altitudes greater than 125 m. 

For the spring, the mean flight altitude was 441.3  +/-  2.5 m, with a sample population of 16,151 individuals.  The highest percentage of individuals had flight altitudes between 101 – 200 m.  Furthermore, 14.0% of the total sampling population flew at altitudes that were lower than 125 m.  This coincides with the middle 50% of the sampling distribution overlapping with the risk-zone.  This survey suggests that spring migrations are twice as likely to move through the proposed development area.

The results of the Nocturnal Marine Radar Survey are argued to be similar to other New York State sites, as well as to other sites across the Eastern United States.   The migration directions are slightly more angled towards Southwest in the Fall and Northeast in the Spring, however this could be attributed to the presence of Lake Ontario.  Passage rates are similar to those of other New York States.  Furthermore, the collision risk is also similar to other sites in New York State.  The researchers suggest placing the turbines 1.5 kilometers or greater from the shoreline to minimize risk.

B.  Raptor Migration Surveys

The goal of the Raptor Migration Survey was to use point count surveys to assess the use of the Cape Vincent area by migrating raptor species in addition to other large bird species.  Within circular plots, point counts were conducted with surveyors scanning their surrounding area for raptor and/or other large bird species.  Three survey points were chosen within the proposed development area for their 360-degree visibility advantages.  Surveys were conducted for the spring 2006, fall 2006 and spring 2007 migration periods.  Methods for the survey were borrowed from the Hawk Migration Association of North America (HMANA), and are fully explained within the Draft Final Report.

A survey was conducted at each point for the spring 2006 migration season, which recorded 1,581 individuals in the end.  Out of the total, 91 of these individuals were raptors, spread across 9 species.  Turkey vulture was the most commonly seen raptor species (51 indiv.), next of which was the red-tailed hawk (8 indiv.). 

Unlike the spring season, a survey was conducted 10 times at each point for the fall 2006 season.  These surveys identified 8,521 individuals, of which 228 individuals were raptors, spread across 9 species.  Northern harrier was the most common species (87 indiv.).  Again, turkey vulture and red-tailed hawk were common. 

For spring 2007, a survey was conducted at each point 7 times.  The total amount of identified individuals was 2666, of which 232 were raptors, spread across 8 species.  Like 2006, the turkey vulture was the most commonly seen species (105 indiv.), and again rough-legged hawk came second (38 indiv.), with red-tailed hawk coming in third (36 indiv.). 

Totals for the three surveys were 12,768 individuals, with 611 raptors identified across 13 different species. 

Out of all the surveys, Canadian Goose and unidentified gull species were the most common birds observed.  However, other species of raptors that were identified included the following: broad-winged hawk, Cooper’s hawk, osprey, merlin, and bald eagle. 

The results of the surveys show that the Cooper’s hawk is at considerable risk due to the fact that all individuals observed were within the risk-zone.   The sharp-shinned hawk shows the next highest risk, as 58.33% of all individuals identified were in the risk-zone.  However, these species, along with all other hawk species observed, exhibit low-risk factors due to the fact that their migratory usage of the Cape Vincent area in spring is low compared to other NYS areas.  Overall, hawk use in the area is considerably lower than most other areas studied.  In the contrary, turkey vultures can be expected to experience the highest risk due to their high usage of the area, even though these risks may be relatively low.

C.  Breeding Bird Surveys

The intent of the Breeding Bird Survey was to assess the usage of the area by resident breeding birds.  Essentially, the survey sought to find out how many birds that live in the Cape Vincent area use the proposed area as breeding grounds.  Twenty survey points were selected and spread out to cover as much as the proposed development area and available habitats as possible.  Survey methods were adopted from the 2001 United States Geological Survey Breeding Bird Survey.  Although the emphasis was to observe within 400 m of the survey points, all birds were recorded.  Two surveys were conducted at each of the survey points between June and July of 2006. 

A total of 1080 individuals were recorded during the survey period, which comprised 59 different species.  Of these totals, the following species were the most common: European starling; red-winged blackbird, and bobolink.  It is no surprise that such species were recorded, as they are most commonly found within agricultural and grassland habitats, as well as the edge habitats surrounding them.  Cape Vincent has all three habitats available. 

The species of greatest concern that were identified are listed below:

1.  Northern harrier (NYS Threatened species) 2.  Horned lark and the grasshopper sparrow (NYS Species of concern) 3.  Bobolink and wood thrush (included in the USFWS 2002 Birds of Conservation Concern list)

D.  Nocturnal AnaBat Surveys

Much like the Marine Radar Surveys, the AnaBat surveys utilize radar to survey the usage rates of bats within the spring and fall migrations, as well as during the summer breeding season.  The spring sampling period was conducted between April 13^th – May 29^th, the fall sampling between August 13^th – October 16^th, and the summer sampling occurred between June 28^th – August 8^th.  Both stationary and mobile AnaBat survey units were employed, so as to cover the most amount of area as possible.  AnaBat works by receiving the frequency of the echo-location used by bats, matches it to a specific species’ frequency, and then records it. 

Of all the bat calls that were recorded, 93% of them occurred during August 15^th and August 21^st, suggesting that the most bat activity in the area occurs during the summer breeding period.  After qualitative screening processes, only 132 of 464 calls recorded in the summer period contained enough data to positively identify the bat species in the area.  The four bat species identified and the number of recorded calls are listed below: Eastern red bat:  22 Little brown bat:  50 Northern myotis:  44 Indiana bat:  16

E.  Waterfowl and Winter Raptor Surveys

The purpose behind the Waterfowl and Winter Raptor Surveys was to assess the use of the proposed development area by wintering and migrant waterfowl and raptor species.  This was largely in response to the initial concern expressed for such species when the project was first proposed.  Driving transects conducted on all the roads within the development area provided a survey of nearly the entire area, with the assistance of nine point surveys that were conducted at fixed points.  Waterfowl, raptors, and other waterbirds were recorded for the survey.  The surveys were conducted between November 5^th, 2006 and March 1^st, 2007 with a combined total of more than 40 hours of survey time.

Close to 800 individuals were found during both the driving transects, as well as for the fixed point surveys.  Each survey identified nearly 150 different species.  Overall, the study found that the Canadian goose is by far the most common wintering waterfowl bird in the area.  This is largely because Canadian goose is reaching points of overpopulation.  Any effects to the wintering population of Canadian goose are considered not to be significant to the overall population.  In addition, the red-tailed hawk and the rough-legged hawk were the most common raptor species.  References

Kerns, J., Young, D., Nations, C. et al.  (2007, August).  Avian and Bat Studies For Proposed St. Lawrence Windpower Project, Jefferson County, New York.  Retrieved from: http://stlawrencewind.com/SEIS/SectionsPDF/Appendices/AppendixE_1_BBStLawrenceWind2006FinalReport.pdf

FWS Guidelines

III.  Wind Energy Guidelines:  Fish and Wildlife Service

Before any wind energy project can be developed in an area, its development must agree with the guidelines set forth by the Fish and Wildlife Service.  The Fish and Wildlife Service has provided a set of federally regulated policies that are intended to minimize the impacts on any species in the area.  Such regulations borrow policies from a variety of similar federal organizations, and laws.

The language of the guidelines is mostly general, as they are meant to be applied in a variety of different circumstances and cover a variety of different scenarios.  In addition, the guidelines are meant to incorporate considerations for all fish, wildlife, and habitats.  This requires the guidelines to be flexible.  Furthermore, the guidelines acknowledge that future revisions and adaptations will have to be made for unique circumstances.  They also admit that not all circumstances and scenarios can be addressed in the published guidelines. 

 These regulations are especially important in protecting the integrity of any threatened and endangered species.  Not only are these guidelines intended to protect the individual fish and wildlife species, they are also used to protect habitat for the species as well.  After all protecting the health of a habitat is just as important as protecting the species themselves.  How a company chooses to develop its project will have to conform to these regulations.  When the guidelines are unclear on how to address specific issues, the company or organization in charge of the operation is responsible assessing an action’s impact.  The organization is charged with what is known as the “burden of proof”, which requires sufficient evidence to prove that an action will not create significant impacts to the species and/or environment.  

The document we used to research such guidelines is titled the “U.S. Fish and Wildlife Draft Land-Based Wind Energy Guidelines”, and was published with the work of the Wind Turbines Advisory Committee.  The Fish and Wildlife Service established the committee in March 2007.  The guidelines follow a tiered organization, with each tier addressing a particular issue concerning the risks to fish and wildlife.  Risks are defined as being both (1) direct and indirect impacts to fish, wildlife and habitat, and (2) the extent to which these impacts will occur.  These risks are complicated by differing species and habitat composition, the technology used in the wind project, weather conditions, and a variety of other factors. 

Below is a paraphrased list of the risk tiers:

1.     Tier 1 – Evaluation of the landscape in where the proposed project is to be developed.  These evaluations are based on the overall sensitivity of the area.

2.     Tier 2 – A general outline of the site(s) in broad characterizations.

3.     Tier 3 – The pre-construction assessments, which would include any before and after scenarios and/or impacts.  Projected impacts on

4.     Tier 4 – Post-construction assessments of any manifest impacts.  Any direct influences that the wind project had on mortality rates are addressed in this tier.

5.     Tier 5 – Any further research that can help mitigate the impacts of the wind project.  This tier is integral to preserving the Service’s goal of avoiding impacts.  Results from this research may require specific actions on part of the developer to minimize or eradicate specific impacts.

Special considerations for projected mortality rates are outlined within Tier 3.  Impacts on mortality rates are described as Low, Moderate, and High.  These impacts include those for both individual bat and bird species.  If the impacts are expected to be low, two years of monitoring and assessment is required to verify the impacts.  For moderate impacts, there is a three-year requirement for monitoring.  Finally, the high impacts require a minimum of five years of observation.  Once these requirements are met, the observations can be used to determine whether or not the wind turbines will produce an increase in mortality rates.  If it is shown that impacts will in fact cause an increase in mortality rates, continued research is required, as well as the implementation of any adaptive technologies that will decrease fatalities.  In addition, increased involvement and cooperation with the Fish and Wildlife Service will be required to ensure the avoidance of impacts. 

Tier 4 focuses its attention on the post-construction impacts that are felt by species and their respective habitats.  Direct impacts on habitats can be categorized as follows: habitat loss, modification and fragmentation, barriers, displacement, and noise.   This includes considering the overall size of the project, amount of turbines, placement of turbines and any access roads.  

Tier 5 is a continuous process, which allows the private company, as well as federal and independent organizations to continue evaluating impacts and ways to mitigate them. 

Chapter 6 describes the mitigation process involved in wind power projects.  Mitigation is defined by the Service as “avoiding and minimizing adverse effects, and when appropriate, compensating for adverse effects” (Fish and Wildlife, 62).  Most of these mitigation methods are outlined in the Fish and Wildlife Service’s Mitigation Policy.  The first goal is to avoid effects, because compensation implies that impacts have already manifested themselves, and that there is a need for change.  Furthermore, compensation is more often appropriate for impacts on habitat than impacts on wildlife.  Compensation for wildlife is often sought after when wildlife loss is significant.  In addition, if compensation is required, it is often far more expensive than early avoidance methods.  However it must be noted that not all mitigation policies can be agreed upon during the pre-construction stage.  The inability to concretely forecast all the possible outcomes means that some impacts can only be observed in the post-construction stage.  

The Service emphasizes that early cooperation with the Service is integral in avoidance tactics. Early avoidance methods involve cooperation with the development company, the Fish and Wildlife Service, as well as any other relevant agencies.  Factors such as species of special concern and the overall stability of the habitat are addressed during these early discussions.  The necessity for avoidance is often reinforced by any conservation plans, regulations, and/or permits that are associated with that area.  Different organizations and policies will require considerations for differing species and/or habitat.  For instance, the Fish and Wildlife Service may call for avoidance measure for a specific species, while another local agency may argue for another species, and vice versa.  This calls for a total assessment of concerns and the ways that a developer can appease those concerns. 

A number of mitigation methods are described in the Guidelines report, and a few a listed below:

1.     Reduction of cut-in speeds (the speed at which the blades spin) have shown to reduce fatalities.

2.     Blade idling decreases the overall risk factor by decreasing the amount of time the blades spend revolving.

3.     Minimal lighting on turbines, due to the fact that many migrating birds are attracted to lights, especially during inclement weather.

4.     Keeping turbines from cliffs where raptors are known to nest and soar. 

5.     Painting wind turbines alternate colors

6.     Use of ultrasonic devices that deter bats through the use of broadcasted frequencies.  Furthermore, devices referred to as “laser bird-alerting warning devices” are similar to those used at airports and show a promise of deterring birds.

For further information regarding the Fish and Wildlife Service’s Wind Energy Guidelines, feel free to access the document at the following URL:

http://www.fws.gov/windenergy/docs/Wind_Energy_Guidelines_2_15_2011FINAL.pdf

Interactions

IV.  Interactions with Bat and Avian Species:  Turbine and Wildlife Relationships

While the wind energy industry continues to develop, wind turbines themselves grow as well.  Today, wind turbines can stand between 200 and 260 feet tall, as opposed to the earlier models that were between 60 and 80 feet tall.  This drastic change in size has resulted in a higher influence on the surrounding bat and avian species, as well as their habitats.  The blades of a wind turbine typically spin at a rate of 132 to 182 miles per hour, which produces significant alterations to the surrounding air and wind conditions.  Not only do the overall size of a turbine and the speed of its blades produce risks for birds and bats, but the speed at which the turbines spin is also highly influential.

As part of a general analysis of the interactions between wind turbines and bat and avian species, the National Wind Coordinating Collaborative (NWCC) produced a document that addressed general questions and concerns relating to these interactions.  The NWCC is a group of stakeholders that was formed in 1994 with the goal of promoting “environmentally, economically, and politically sustainable” projects within the wind energy sector.  Their document was published in the spring of 2010, and is entitled “Wind Turbine Interactions with Birds, Bats and their Habitats: A Summary of Research Results and Priority Questions”.

 Observations and analyses of wind energy projects across North America are incorporated in this document.  Discussions on key impacts to both species and their habitats are addressed, as well as the current research results and the gaps that remain in understanding the interactions between wind energy and bat and avian species. 

The document presents its findings in a three-tiered outline, and our discussion of the document will follow suit.  The tiers are outlined and discussed below.

“What Studies Have Shown”

Research findings that provide a picture on what developers and researchers currently know about the interactions between wind energy and bat and avian species are presented in this section.  These findings are a conglomeration of research methods and protocols from studies across North America.  The extent of analysis for such studies has improved drastically since the original fact sheet that was published by the NWCC in 2004. 

The first issue addressed is the direct and indirect effects on mortality rates.  The document shows that mortality rates of raptors at wind turbine sites averages between 4 and 14 individuals per turbine per year.  This is argued to be insignificant, especially in comparison to the increased bat mortality rates.  Most bat fatalities are recorded during the spring and fall migration seasons.  However, further research on bat population distributions and migration patterns are required to further understand the extent of the effects on bat species.  It should be noted that the differences amongst regional conditions produces a high variability of mortality rates.  Detailed graphs of these variations are found on page 3 of the fact sheet. 

Songbirds are of high concern, as roughly three quarters of the total bird fatalities accounted for at wind turbines.  Although fatalities are substantially lower than other anthropogenic threats to songbirds (vehicles, infrastructure, pesticides, etc), fatalities from turbines are likely to increase as wind turbines continue to be developed. 

The Federal Aviation Association (FAA) regulations on the lights used to illuminate wind turbines are not found to increase mortality rates for either bat or avian species. 

For raptors, the best way to reduce direct impacts is to place wind turbines away from areas that raptors use.  Such areas would include cliffs and ridges.   Simply moving turbines away from these sites would avoid significant raptor fatalities. 

“What is Less Understood”

The NWCC addresses a critical issue within wind energy projects:  the current methods of using pre-construction research to predict post-construction fatalities are currently insufficient.  The results of post-construction monitoring infrequently reflect the pre-construction predictions.  These differences require a refurbishment of the way that we use pre-construction research to predict future fatalities. 

Although the following observations have been argued to be true, they have yet to be concretely proven.  It has been argued that placing turbines farther away from prey populations will result in fewer raptor fatalities, as there will be a reduction in raptor use.  Furthermore, use of larger turbines results in smaller wind energy developments and may reduce raptor collisions.  In addition, although little research exists on coastal wind energy developments, current research argues that waterbird and waterfowl fatalities are relatively low.

In regards to bat species, the following observations suggest specific impacts but are still loosely understood.  For example, the influence of weather patterns is considered to be a strong factor in influencing bat mortality, however, further research is required.  Current research shows that adult male bats may be at a particularly higher risk than other bats.  Although this interaction is poorly understood, it is currently argued that late summer/early fall breeding patterns may entice male bats to congregate around wind turbines with the intent of attracting females. 

“Areas Where Little Is Known”

The biggest uncertainty concerning wind energy is the extent to which it will expand.  As the industry continues to grow and more and more wind projects are developed, there will be a growing need for continued research.  Because we cannot predict the extent to which wind energy will expand, our understanding of its future effects is impossible to comprehend. 

The differences amongst habitat types confound our understanding of favorable development sites.  Current research suggests that agricultural sites produce lower migrant songbird fatalities than forested sites.  However, this correlation remains unclear. 

Barotrauma, a condition that results in internal injuries from sudden changes in air pressure, is still poorly understood as it relates to bats.  Because wind turbine blades spin at a high rate of speed, wind vortices are created in their wake and create air pressure changes.  These changes produce barotraumas for bats and could be a significant factor in the increased mortality rates.  However, current studies are struggling to assess the extent of barotraumas on bats. 

Furthermore, it still remains unclear on how topography and other geographical factors affect bat mortality rates.  Developing a better understanding of how different habitats produce different interactions between bats and wind turbines could result in methods to place wind turbines out of range of high bat-use areas.  In addition, there is a need to understand whether or not bats are attracted to wind turbines, as it is currently assumed that bats congregate around turbines.  This possible attraction could be due to a higher concentration of insects, sounds produced by turbines, as well as the bats intents to use turbines as roosting sites. 

In conclusion, it is impossible to predict how wildlife will adapt to large wind turbines being placed in their habitats.  The ability for wildlife to adjust to new influences in their environment is referred to as habituation.  Researchers are currently unsure how species will habituate to wind farms, though it is presumed that wildlife will adapt to at least some extent. 

All information and references included in this summary are adapted from what is provided in the NWCC’s “Wind Turbine Interactions with Birds, Bats and their Habitats: A Summary of Research Results and Priority Questions”.  Any references are references to the work of the respective authors. 

National Wind Coordinating Collaborative (2010, Spring).  Wind Turbine Interactions with Birds, Bats and Their Habitats:  A Summary of Research Results and Priority Questions.  Retrieved from:
https://www.nationalwind.org/assets/publications/Birds_and_Bats_Fact_Sheet_.pdf

Species of Concern

V.  Species of Special Concern

The following is a list of species that are likely to experience significant impacts that result from wind energy projects.  Species that are common to the Cape Vincent area are labeled with a (CV) label to the right.  The order of the species listed is not an a hierarchical manner, and do not reflect any bias or any significance placed upon one species over another.  

Bats

 Eastern Red Bat (CV)
Indiana Bat (CV)
Northern Myotis (CV)
Little Brown Bat (CV)
Silver Haired Bat
Brazilian Free-tailed Bat
Hoary Bat

Birds
Northern Harrier (CV)
Cooper's Hawk (CV)
Red-tailed Hawk (CV)
Rough legged Hawk (CV)
Bobolink (CV)
European Starling (CV)
Red-winged blackbird (CV)
Turkey Vulture (CV)
Canadian Goose (CV)
American Crow
Prairie Grouse
Songbirds of all species


This list was largely adapted from information provided in the The Final Report on Bat and Avian Studies (Supplementary Environmental Impact Statement) for the St. Lawrence Windpower Project.


Kerns, J., Young, D., Nations, C. et al.  (2007, August).  Avian and Bat Studies For Proposed St. Lawrence Windpower Project, Jefferson County, New York.  Retrieved from: http://stlawrencewind.com/SEIS/SectionsPDF/Appendices/AppendixE_1_BBStLawrenceWind2006FinalReport.pdf

Avoidance

VI.   Avoidance:  Methods to Reduce Risk

Below is a conglomeration of possible methods, practices and policies that could potentially reduce the risk to both bat and avian species.  The possible benefits of these methods are separately outlined for the respective benefits to bats and birds.  Most of these methods reflect general benefits, and do not necessarily show benefits for individual species. 

The methods outlined below are paraphrased from the variety of resources used in our discussion.

Bats

-       Reduce wind turbine operation times when wind speeds are low.  Because lower wind speeds reduce the amount of energy that can be generated, it is not necessary to operate all turbines in an operation at once.  Furthermore, bats are more likely to be active during periods of low wind speeds.  Reducing or ceasing operation during times of low wind speed will reduce the overall risk potential to bats because it is presumed that more bats will be active during such conditions.  (National Wind Coordinating Collaborative, 2010)

-       Reduction of blade speeds could produce fewer alterations to the surrounding airspace’s air pressure.  Few alterations to air pressure could lead a decreased risk of barotrauma.  (Fish and Wildlife Service, 2004)

-       Use of ultrasonic devices that project frequencies proven to deter bats.  Because bats use echo-location to navigate, ultrasonic devices may be the best possible method to reducing bat mortalities.  (Fish and Wildlife Service, 2004)

Birds

-       An effect known as “motion smear” is known to decrease the ability for birds to identify spinning wind turbines.  It has been suggested that using alternative paint colors (such as yellow or red), or the use of ultra-violet (UV) paint may reduce collision rates.  (National Wind Coordinating Collaborative, 2010)

-       Use of devices known as “laser bird-alerting” devices that are currently used to deter birds from airports of energy distribution infrastructure.  (Fish and Wildlife Service, 2004)