Vultures as Surrogates for Eagles and Other Large Birds in Bias Trials for Wind Farm Fatality Monitoring

Chris Farmer

DNV GL Energy

Dr. Farmer is the Principal Biologist in Environmental and Permitting Services (EPS) for the North America business group in the Chalfont, PA office of DNV GL. He is an ecologist with 18 years of experience studying birds, ungulates, and carnivores, specializing in eagle surveys and take permitting, habitat studies, survival analysis, population ecology, population modeling, and statistical ecology. He provides leadership and mentoring to biologists in EPS, and is also a leader of business development for biological services. Mr. Farmer’s current career focus is providing biological and strategic support to the wind, solar, and electrical transmission industries. He provides support to due diligence and permitting for energy projects including pre-construction wildlife surveys, NEPA analyses, mitigation plans, habitat conservation plans (HCP), eagle conservation plans (ECP) and other documents required under the endangered species act, bald and golden eagle protection act, and other environmental rules and regulations. He has represented clients in negotiations with regulatory agencies and promotes a high level of technical competence in our work products. He has served as an associate editor for the Journal of Raptor Research since 2010. He also served on the board of directors of the Ornithological Council, representing the American Ornithologists’ Union from 2009 to 2015, and is a member of the Eastern Golden Eagle Working Group.

Abstract

In post-construction fatality monitoring (PCFM) of wind projects, the amount of time a bald (Haliaeetus leucocephalus) or golden (Aquila chrysaetos) eagle carcass remains detectable (carcass persistence), can influence the ability to detect fatalities of these species, as well as influence the accuracy and reliability of the fatality estimates. Due to their protected status under the Bald and Golden Eagle Protection Act, it is difficult to accurately estimate carcass persistence for eagles using traditional bias trials, which rely on placing carcasses of monitored species to estimate their persistence. Consequently, limited research is available to reliably determine carcass persistence for eagles. As a result, sampling intervals for eagle monitoring are often more reflective of surrogate persistence than eagle persistence. Typically, surrogate species such as domestic pheasants (Phasianus colchicus) are used in carcass persistence estimation for eagles; however, it is probable that these persist for different durations than eagles. Black vultures (Coragyps atratus) are closer in size and plumage to eagles than typical surrogates, and both of these factors may influence carcass persistence. Therefore, to more accurately estimate eagle carcass persistence, we placed and monitored carcasses of black vultures within a proposed wind farm to estimate their persistence. Carcasses were monitored for 60 days in each of three seasons, and we measured their mean seasonal persistence time and also derived bootstrapped estimates of mean persistence based on survival models fitted to the data. Our results indicate that carcasses of large raptors such as vultures and eagles persist in detectable form up to four months after deposition. Thus it is appropriate to consider this long persistence time in determining sample intervals for PCFM designed to monitor for eagle fatalities. Doing so will improve accuracy of facility-wide fatality estimates, and could provide for dramatic cost savings compared with sampling schemes that assume lower persistence times for eagles.

Authors

Chris Farmer (DNV GL Energy)
Thomas Snetsinger (Tetra Tech, Inc)
Dave Phillips (Apex Clean Energy, Inc)

Topic Areas

Assessing direct and indirect effects on wildlife and their habitats , Evaluating novel approaches (e.g., conceptual, methodological, technological) to avoiding, , Birds , Eagles , Raptors , U.S. - No Specific Region , Impact assessment , Methodology , Land-based

Session

00 » Posters (12:30 - Friday, 2nd December, Centennial Ballroom)

Presentation Files

The presenter has not uploaded any presentation files.

Email Support • Blog • Privacy Policy • Cancellation Policy