[Federal Register Volume 83, Number 120 (Thursday, June 21, 2018)]
[Notices]
[Pages 28858-28860]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-13358]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[FWS-HQ-MB-2017-0092; 91200-FF09M20300-189-FXMB123109EAGLE]


Updated Collision Risk Model Priors for Estimating Eagle 
Fatalities at Wind Energy Facilities

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of availability and request for comments.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) uses a collision 
risk model (CRM) to predict the number of golden and bald eagles that 
may be killed at new wind facilities. The model incorporates existing 
information on eagle exposure and collision probability in the form of 
prior distributions (priors). The Service has undertaken an analysis to 
update the priors using all available data that meet specific criteria 
for both species of eagle. This notice announces the availability of a 
summary report of that analysis, which generates new exposure and 
collision priors for both species of eagle. We are soliciting public 
comments on the summary report, which will be considered by the Service 
before using the new priors in the CRM.

DATES: To ensure consideration of written comments, they must be 
submitted on or before August 20, 2018.

ADDRESSES: You may submit written comments by one of the following 
methods:
    Electronically: Go to the Federal e-Rulemaking Portal: http://www.regulations.gov. Search for FWS-HQ-MB-2017-xxxx, which is the 
docket number for this notice, and follow the directions for submitting 
comments.

[[Page 28859]]

    By hard copy: Submit by U.S. mail or hand-delivery to Public 
Comments Processing, Attn: FWS-HQ-MB-2017-0092; Division of Policy, 
Performance, and Management Programs; U.S. Fish and Wildlife Service; 
MS: BPHC; 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Request for Information below for more information).
    We request that you send comments by only one of the methods 
described above. We will post all information received on http://www.regulations.gov. This generally means that we will post any 
personal information you provide us (see the Public Availability of 
Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: Eliza Savage, at 703-358-2329 
(telephone), or <a href="/cdn-cgi/l/email-protection#32575e5b48536d415344535557725445411c555d44"><span class="__cf_email__" data-cfemail="8de8e1e4f7ecd2feecfbeceae8cdebfafea3eae2fb">[email protected]</span></a> (email). Individuals who are 
hearing impaired or speech impaired may call the Federal Relay Service 
at 800-877-8337 for TTY assistance.

SUPPLEMENTARY INFORMATION:

Background

    The U.S. Fish and Wildlife Service (Service) uses a collision risk 
model (CRM) to predict the number of golden and bald eagles that may be 
killed at new wind facilities (USFWS 2013; New et al. 2015). The CRM 
incorporates existing knowledge of eagle use around a proposed wind 
facility (exposure) and the probability of an eagle colliding with an 
operating turbine (collision probability). Essentially, the CRM uses 
three estimates to generate an annual eagle fatality estimate in the 
form of a probability distribution. These estimates are: (1) A project-
specific estimate of eagle exposure; (2) a project-specific estimate of 
the amount of hazardous area and time that will be created by the 
project; and (3) an estimate of the probability that an exposed eagle 
that enters the hazardous area will be struck and injured or killed by 
a turbine blade. The median (50th quantile) fatality rate of the CRM-
generated probability distribution is the point on the distribution at 
which there is an equal risk of under- and overestimating eagle 
fatalities. The Service uses the 80th quantile of the CRM fatality 
probability distribution to determine the take limit for incidental 
take permits, which lowers the risk of underestimating eagle take to a 
20% chance.
    In our 2016 revision to the eagle take regulations (81 FR 91494, 
Dec. 16, 2016), the Service reaffirmed both our intent to use the CRM 
to obtain initial estimates of eagle fatalities at new wind facilities, 
and that we would undertake a review of the background data used in the 
model to generate the estimates. The model is constructed using a 
Bayesian framework, and as such incorporates existing information on 
eagle exposure and collision probability in the form of prior 
distributions (priors). The priors are formally combined with site-
specific data on exposure and the amount of hazardous area and 
operational time for a site to estimate the expected number of annual 
eagle collision fatalities.
    The current priors for the CRM use data for golden eagles from nine 
sites with complete survey effort information for exposure, and four 
sites for collision probability (New et al. 2015). There were no data 
available to estimate parameters specific to bald eagles when we 
initially developed the model, so the golden eagle priors were used as 
surrogates for bald eagles. Public comments on the 2016 eagle rule 
revision were critical of the Service's CRM because the priors for 
golden eagles had not been updated to include new information, and 
because priors have not been developed for bald eagles even though data 
on exposure and collision probability are now available for this 
species. In response to these comments, the Service committed to 
updating the golden eagle priors, and to explore whether sufficient 
data exist to develop separate bald eagle exposure and collision 
priors.
    The Service has undertaken that analysis using all available data 
that meet specific criteria for both species of eagle. This notice 
announces the availability of a summary report of that analysis, which 
includes new exposure and collision priors for both species of eagle. 
The report may be downloaded from the Federal e-Rulemaking Portal: 
http://www.regulations.gov. Search for FWS-HQ-MB-2017-0092. You can 
also find the report on the Service's website at: https://www.fws.gov/birds/management/managed-species/eagle-management.php. The Service 
intends to incorporate these updated priors into our CRM after 
considering comments received in response to this notice; that update 
will be in the form of a revised version of Appendix D of the Eagle 
Conservation Plan Guidance (USFWS 2013).
    For this update, the Service reviewed data sets for 419 wind energy 
facilities, but many did not meet our criteria for incorporation into 
the priors (see the summary report for criteria used to filter 
projects). Data from 71 new and the nine original wind projects were 
used for the updated exposure priors. Of these 80 sites, 61 provided 
data for golden eagles and 59 for bald eagles. For the collision 
priors, 18 new sites in addition to the original four sites were 
identified as having data sufficient to include in the updated 
collision priors. We used data from 21 sites for golden eagles and 14 
for bald eagles in the collision-prior update. The updated exposure 
prior is lower for both species than the prior currently in use. The 
updated collision prior is slightly lower than the current prior for 
golden eagles and higher for bald eagles.
    Many of the commenters on the 2016 eagle rule revision encouraged 
the Service to develop a specific bald eagle prior because they believe 
collision risk for bald eagles is lower than for golden eagles. The 
data available to the Service suggest that there is more variation in 
both exposure and collision risk for bald eagles, and that uncertainty 
results in a higher expected collision probability for this species. 
The Service does not regard this outcome as counter-intuitive, because 
the range in abundance of bald eagles across the landscape is far 
greater than for golden eagles, and where bald eagles are abundant, 
they engage in social behaviors and intra-specific interactions that 
may make them more vulnerable than golden eagles to collisions (81 FR 
91552). Thus, the implication that bald eagles are at high risk at a 
few wind facilities, while their risk is much lower at many others, is 
tenable. The Service acknowledges, however, that the bald eagle 
collision prior is based on data from relatively few sites that do not 
span the range of bald eagle density conditions that exist across the 
country, and therefore may not be representative of all locations. 
Given this, the Service is considering three alternatives for how to 
incorporate species-specific priors for bald eagles into the CRM and 
fatality modeling process:
    (1) Use the updated species-specific priors, and use the 80th 
quantile of the CRM fatality estimates as the initial permitted take 
number for permits, as is the current practice.
    (2) Use the updated species-specific priors, but because the status 
of bald eagles is secure, adopt a risk-tolerant policy for bald eagles 
and select a more liberal quantile on the CRM fatality distribution as 
the initial permitted take number for this species.
    (3) Given the limitations in data available to inform the bald 
eagle priors, initiate an expert elicitation process to further refine 
the bald eagle priors.
    Under any of these scenarios, the Service would use data submitted 
under

[[Page 28860]]

permits to make updates to the priors in the future.
    Alternative 1 would mean that for a similar level of eagle use 
observed at a project site, the Service would use higher fatality 
estimates for bald eagles than for golden eagles. Alternative 2 would 
be a decision by the Service to be more `risk-tolerant' for bald 
eagles. This would mean that initial fatality predictions would be 
lower, however it would also likely mean that more permits would have 
to be amended to increase the permitted take over time (i.e., the 
Service would be underestimating take more often). Alternative 3 would 
be a decision by the Service that more information is needed to 
understand the potential variability of exposure and collision 
probability for bald eagles. Such a process could result in either 
higher or lower (or more variable) priors. With this notice, we are 
soliciting input from the public on these three alternatives, and we 
will take those comments into consideration in making a final decision.
    Many commenters on the draft 2016 rule urged the Service to adopt 
changes to the golden eagle CRM priors based on a recent peer-reviewed 
scientific article by Bay et al. (2016). Service staff coordinated with 
authors of the Bay et al. paper in development of this update, and all 
data used in the Bay et al. paper that were available to us and that 
met our criteria were incorporated. The Service decided not to 
incorporate the results of the Bay et al. paper directly, however, for 
two main reasons. First, the Service could access and utilize more data 
than were used in the Bay et al. paper, and so our updated priors 
incorporate more recent information from a wider range of projects and 
sites than were used by Bay et al. Second, the Bay et al. analysis used 
a fatality estimator that did not account for the possibility of 
undetected eagle deaths during mortality monitoring when no dead eagles 
were found. The Service uses models in our update that account for 
imperfect detection when dead eagles are not encountered during 
monitoring, because there is ample evidence that finding no dead eagles 
does not mean there were no eagle fatalities. Thus, although the 
Service's updated collision probability for golden eagles is higher 
than that reported by Bay et al., our approach is more accurate and 
consistent with our risk-averse policy with respect to estimating and 
managing eagle take.

Public Availability of Comments

    Written comments we receive become part of the public record 
associated with this action. Before including your address, phone 
number, email address, or other personal identifying information in 
your comment, you should be aware that the entire comment--including 
your personal identifying information--may be made publicly available 
at any time. While you can ask us in your comment to withhold your 
personal identifying information from public review, we cannot 
guarantee that we will be able to do so. All submissions from 
organizations or businesses, and from individuals identifying 
themselves as representatives or officials of organizations or 
businesses, will be made available for public disclosure in their 
entirety.

Literature Cited

    Bay, K., Nasman, K., Erickson, W., Taylor, K., Kosciuch, K. 
(2016). Predicting Eagle Fatalities at Wind Facilities, Journal of 
Wildlife Management 80:1000-1010.
    New, L., Bjerre, E., Millsap, B., Otto, M.C., Runge, M.C. 
(2015). A Collision Risk Model to Predict Avian Fatalities at Wind 
Facilities: An Example Using Golden Eagles, Aquila chrysaetos, PLOS 
ONE, journal.pone.0130978.
    U.S. Fish and Wildlife Service. 2013. Eagle conservation plan 
guidance. Module 1-land-based wind energy. Version 2. Division of 
Migratory Bird Management, Washington, DC. URL http://www.fws.gov/migratorybirds/pdf/management/eagleconservationplanguidance.pdf.


    Dated: April 6, 2018.
Susan Combs,
Senior Advisor to the Secretary, Exercising the Authority of the 
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 2018-13358 Filed 6-20-18; 8:45 am]
 BILLING CODE 4333-55-P


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