Determining Potential Take of Indiana Bat (Myotis sodalis) from Wind Energy Facilities

Transcription

1 Determining Potential Take of Indiana Bat (Myotis sodalis) from Wind Energy Facilities DAVID YOUNG WESTERN ECOSYSTEMS TECHNOLOGY, INC. CHEYENNE, WYOMING David Young, Senior Manager

2 Background and Introduction 2 In the fall of 2009, two events occurred that elevated the endangered Indiana to one of the most prominent issues facing wind energy development throughout the Midwest and eastern U.S. 1. A federal court determined that operation of a proposed wind facility in West Virginia would lead to take of Indiana, and 2. An Indiana fatality was recorded at an existing wind facility in Indiana.

3 Background and Introduction 3 These circumstances resulted in elevated scrutiny of wind projects throughout the range of Indiana s.

4 Endangered Species Act 4 The Endangered Species Act (ESA) has provisions by which an Incidental Take Permit (ITP) may be acquired to cover:.take that is incidental to, and not the purpose of, carrying out an otherwise lawful activity. Section 10: Exceptions 10(a)(1)(A) Enhancement of survival permits (research/recovery), safe harbor, CCAs 10(a)(1)(B) Incidental Take Permits

5 Incidental Take 5 Primary responsibility of an ITP Applicant under Section 10 is developing a Habitat Conservation Plan (HCP). HCP Handbook defines Mandatory Elements of an HCP: Under the Endangered Species Act [Section 10(a)(2)(A) and ] a conservation plan submitted in support of an incidental take permit application must detail the following information. o Impacts likely to result from the proposed taking of the species for which permit coverage is requested; o..others

6 Incidental Take 6 At the heart of developing an HCP is determining potential take of the listed species at risk. HCP Handbook: In determining the amount of incidental take that will be authorized during the life of the permit, three things must be determined: (1) how incidental take will be calculated; (2) the level of incidental take and related impacts expected to result from proposed project activities; and (3) the level of incidental take that the section 10 permit will actually authorize.

7 Incidental Take 7 So how does one determine how incidental take will be calculated (i.e., the number of animals potentially killed, harmed or harassed) for something that we have basically no examples on which to base our best guess?

8 Incidental Take 8 HCP guidance, how take will be calculated depends on the ability of HCP participants to determine, the number of individual animals of a covered species occupying the project or the number of habitat acres to be affected. Depending on this information, proposed incidental take levels can be expressed in the HCP in one of two ways: (1) in terms of the number of animals to be "killed, harmed, or harassed" if those numbers are known or can be determined; or (2) in terms of habitat acres or other appropriate habitat units to be affected by the project, in cases where the specific number of individuals is unknown or indeterminable.

9 Habitat Equivalency 9 So, can we base take of Indiana s from wind projects on amount of lost habitat? HCP guidance says Yes in terms of habitat acres or other appropriate habitat units to be affected by the project, in cases where the specific number of individuals is unknown or indeterminable.

10 Habitat Equivalency 10 Habitat Equivalency approach Uses habitat loss as the index to take This approach requires a strong correlation of habitat with species presence Data available or collected related to density (#/ac, #/km 2, etc.)

11 Habitat Equivalency 11 Is this approach appropriate for Indiana s? Some Indiana habitat is well defined: roost trees, winter hibernacula, generally associated with forest habitat. If an occupied roost will be lost to the project this method could help define take numbers; However, risk of collision related mortality with wind turbines likely means that take occurs outside of lost habitat, therefore, habitat equivalency (i.e. # per acre) is not a strong correlate for estimating all take of Indiana s from wind turbines.

12 Incidental Take 12 So we re back to the original question, how does one determine the number of animals potentially killed, injured, or harmed for something that we have basically no examples on which to base our best guess? Depending on this information, proposed incidental take levels can be expressed in the HCP in one of two ways: (1) in terms of the number of animals to be "killed, harmed, or harassed" if those numbers are known or can be determined; or (2) in terms of habitat acres or other appropriate habitat units to be affected by the project, in cases where the specific number of individuals is unknown or indeterminable.

13 Incidental Take 13 So how to determine in terms of the number of animals for Indiana s and wind projects? Two acceptable means by which Indiana take can be estimated in the absence of data: (1) surrogate species approach, which utilizes data from similar species to estimate take of the focal species; and (2) collision risk model approach, which uses data on spatial occurrence and behavior to estimate take of the focal species.

14 Surrogate Species Approach 14 Surrogate Species approach Uses comparison with one or more similar species with known impacts. Assumes that risk that leads to impacts between the two species is similar. Useful when there is existing data for the surrogate related to a project. Useful when impacts are defined for the surrogate.

15 Surrogate Species Approach 15 What makes a suitable Surrogate? Data the availability of data is a big plus. For wind projects there is a sizeable growing database related to mortality from turbines. Table 2. Number of observed fatalities by species reported at wind project monitoring studies within range of Indiana. Little brown Tricolored Silverhaired Bigbrown Northern longeared Project Hoary Red Seminol e Unk References Buffalo Mtn, TN Fielder 2004, Fielder et al Mountaineer, WV Kerns and Kerlinger 2004, Arnett et al Mt. Storm, WV Young et al. 2009a, 2009b, 2010a, 2010 b Myersdale, PA Arnett et al Casselman, PA Arnett et al. 2009, Arnett et al. unpubl. data PGC, PA Capouilles and Mumma 2008 Maple Ridge, NY Jain et al. 2007, 2008, 2009 Crescent Ridge, IL Kerlinger et al Total Percent

16 Surrogate Species Approach 16 What makes a suitable Surrogate? This data provides a means by which to estimate take under the assumption that risk to Indiana s is similar to one or more other species. Table 2. Number of observed fatalities by species reported at wind project monitoring studies within range of Indiana. Little brown Tricolored Silverhaired Bigbrown Northern longeared Project Hoary Red Seminol e Unk References Buffalo Mtn, TN Fielder 2004, Fielder et al Mountaineer, WV Kerns and Kerlinger 2004, Arnett et al Mt. Storm, WV Young et al. 2009a, 2009b, 2010a, 2010 b Myersdale, PA Arnett et al Casselman, PA Arnett et al. 2009, Arnett et al. unpubl. data PGC, PA Capouilles and Mumma 2008 Maple Ridge, NY Jain et al. 2007, 2008, 2009 Crescent Ridge, IL Kerlinger et al Total Percent

17 Surrogate Species Approach 17 What makes a suitable surrogate? Arguable examples for wind projects include: little brown, tri-colored, northern myotis All three species ranges overlap Indiana Little Brown Tri-colored Northern myotis Indiana Map source:

18 Surrogate Species Approach 18 What makes a suitable surrogate? While obviously not 100%, all three species have morphological, ecological, and behavioral traits with similarities to Indiana Similarity of traits supports a suitable surrogate if those traits influence risk that leads to impacts. Little Brown Tri-colored Northern myotis Indiana Picture source:

19 Surrogate Species Approach 19 What makes a suitable surrogate? For little brown and tri-colored the susceptibility of these species to wind turbines has been well documented Table 2. Number of observed fatalities by species reported at wind project monitoring studies within range of Indiana. Little brown Tricolored Silverhaired Bigbrown Northern longeared Project Hoary Red Seminol e Unk References Buffalo Mtn, TN Fielder 2004, Fielder et al Mountaineer, WV Kerns and Kerlinger 2004, Arnett et al Mt. Storm, WV Young et al. 2009a, 2009b, 2010a, 2010 b Myersdale, PA Arnett et al Casselman, PA Arnett et al. 2009, Arnett et al. unpubl. data PGC, PA Capouilles and Mumma 2008 Maple Ridge, NY Jain et al. 2007, 2008, 2009 Crescent Ridge, IL Kerlinger et al Total Percent

20 Surrogate Species Approach 20 Additional data needs: Ratio of the two species on the landscape, region, or project area; Documented presence of the surrogate in the project area. In simple terms, and under the assumption that the surrogate and focal species have the same risk of impact, the ratio of the two species can be used to estimate the expected impact to the focal species from the level of known or expected impact to the surrogate.

21 Surrogate Species Approach 21 A simple example: Based on available data we could expect that a 100 MW project may impact 1200 to 3600 s per year, depending on location. Based on available data we could expect that approximately 10% of the mortality from a given project would be of little brown s. Therefore, between 120 and 360 little brown s could be impacted per year, again depending on location. If the ratio of Indiana s to little brown s in the planning area is 1:100 (0.01) then we could expect that on average between 1.2 and 3.6 Indiana s would be taken per year.

22 Collision Risk Modeling 22 Collision Risk Modeling Uses site specific or general data collected on habitat use, spatial occurrence, temporal occurrence of individuals across the landscape or project area to predict impacts. Assumes that risk that leads to impacts is related to overlap of a project or facilities of a project with use areas or occurrence of the species.

23 Collision Risk Modeling 23 So how does one do collision risk modeling for ESA purposes? Develop a may affect situation essentially determine when we have an Indiana and a wind turbine in the same location at the same time.

24 Source: Horn et al. 2008, JWM 72: Collision Risk Modeling 24 May Affect Situation 1. Determine frequency that an Indiana is within the zone of risk 2. Determine frequency of a collision or barotrauma.

25 Collision Risk Modeling 25 Frequency within the zone of risk: Sophisticated statistical means to predict occurrence. RSF models in simple terms, determine which landscape/ habitat variables are the best predictors of known locations of individuals (the response variable). This modeling can define areas across a project or region with the best characteristics for species occurrence.

26 26 Collision Risk Modeling Frequency within the zone of risk: Other methods for predicting occurrence. Activity Indices can be based on acoustic data, radio telemetry. Helps define temporal patterns of occurrence. These indices overlain with the project facilities provides the may affect. Activity Indices

27 Collision Risk Modeling 27 Frequency within the zone of risk: For s and wind turbines the ability to predict in 3 dimensions improves the may affect assessment to account for above ground height of the zone of risk. A study design using an array of sampling stations across the ground and elevated on towers can provide data for modeling use in space. A A A A A A A A Field Forest Edge

28 Collision Risk Modeling 28 Frequency of collision Once we have established an Indiana and turbine in the same locations determine frequency of a collision. Modeling the actual strikes is appropriate in situations with little empirical data on collisions. Computer simulations can be used to define collision risk potential by flying a computer animal through the wind project. 120 Degrees L w deg/sec Bird/Bat Velocity = v

29 Collision Risk Modeling 29 Frequency of Collision Assumptions about avoidance / attraction to turbines are important to the model. Model input: Frequency in the RSA Size of animal (bird, ) Size of turbine RSA Facility single string, array Others travel speed & direction Measure of avoidance (non-collision) Model output: collision probability estimates

30 Determining Take of Indiana Bats 30 Is there a the best method for determining take? Decision based on many variables but availability of data and ability to collect data are strong factors. While habitat based impact assessment has merit, it is unlikely to provide a fully defensible estimate of take in the light of impacts occurring outside of impacted habitat. Surrogate species and collision risk modeling utilize existing and collected data. Which assumptions can you live with the best? Approaches can be combined to corroborate the level of estimated take.

31 Determining Take of Indiana Bats 31 Tying this back to the ESA and HCP guidance: One of the key concepts throughout HCP planning is take levels estimated based on a comparison of proposed activities with species distribution in the plan area. The methods described provide a basis for this comparison as well as the basis for estimating impacts. Preparing an acceptable HCP requires the availability of up-todate biological information on the species being considered The methods described provide a basis for estimating take based on credible scientific and repeatable methods. research efforts on behalf of an HCP should be confined to distribution studies or other studies with a direct bearing on the needs of the HCP. In the event of additional data collection the methods should keep this in mind to focus the efforts on determining how to estimate and the estimate of take.

32 THANK YOU David Young, Senior Manager