In this new feature, AWWI program leaders give a behind-the-scenes look at their work.
This month, Outreach Manager Paige Johnson chats with Dr. Taber Allison, Director of Research and founder of AWWI’s research program about AWWI’s Eagle Program and compensatory mitigation for eagles.
Paige: How did AWWI begin developing new eagle compensatory mitigation strategies?
Taber: This was AWWI’s first major initiative under our eagle program, started in 2011. At the time, the U.S. Fish and Wildlife Service (Service) had just come out with the first version of the Eagle Guidance to establish a process for issuing permits for eagle take at wind energy facilities. The Guidance described how wind energy companies could satisfy the requirements of the 2009 Eagle Rule with respect to bald eagles and golden eagles. Populations of the latter species were potentially declining, and companies were required to offset permitted take in a way that was quantifiable and verifiable. The Service focused on power pole retrofitting as a way for companies to offset permitted take as this was the only mitigation option that was quantifiable and verifiable at that point.
I was new to AWWI, and we were just beginning our research program. As we developed the research program rubric, I was thinking we had a great opportunity to do something for eagles and wind energy. I started talking to other experts who encouraged AWWI to get involved. Working with 10 preeminent eagle experts, we wrote an Eagle White Paper and conducted a workshop. One outcome of the workshop was the recognition of the need for additional options to offset golden eagle take. We hit on the idea to use expert elicitation and began an opportunity for AWWI to make a significant contribution by developing additional options for offsetting eagle take. Our approach was to work with eagle and modeling experts to develop additional offset options that were quantifiable and verifiable.
Paige: What compensatory mitigation strategies has AWWI developed so far?
Taber: We have developed three models to date. The first model was voluntary lead abatement. The model, published in 2015, estimated the quantitative effects of strategies to abate lead poisoning in golden eagles in Wyoming due to ingestion of spent game hunting ammunition.
We then assembled an expanded team of eagle experts and developed the vehicle collision reduction model, published in 2018. This model estimates the number of golden eagles that can be saved by roadkill carcass removal, again based on data from Wyoming.
Models are not empirical evidence though, and the next step is evaluating them. AWWI was recently awarded more than $140,000 from the National Fish and Wildlife Foundation (NFWF) to incorporate data collected by Hawkwatch International into our vehicle collision model and develop a Resource Equivalency Analysis to promote acceptance of the model across the Service.
We now have a third model in development, the eagle habitat model, which has been submitted for publication.
Paige: What is the eagle habitat model?
Taber: This model estimates how habitat improvements that increase abundance of eagle prey will improve eagle productivity, or “grow” eagles. We have developed a manuscript that is currently undergoing peer review. This model is more complex than the other two models where there is a relatively simple cause-and-effect chain of the mitigation and its effect on eagle survival, so the upcoming publication is a first step. The model indicates that you can increase the number of eagle nests through increasing the quality of habitat in the area, and the best option is to do this in landscapes of intermediate habitat quality for eagles.
Paige: What are your plans for future work on eagle compensatory mitigation?
Taber: The habitat model could be used to predict the number of eagle territories that could be added to the area, but it doesn’t explicitly tell land managers exactly what to do to the landscape to increase prey abundance and improve eagle habitat. So, we’re looking at adding components to the model, or sub-routines, if you will, that focus on specific prey species.
Our work with the NFWF funding is intended to promote acceptance of the vehicle collision model. Another next step could be to develop a Resource Equivalency Analysis for the lead abatement model.
I’d also like to expand the options in the mitigation toolbox – for example, quantifying the potential of treating eagle nest parasites, and rehabilitating eagles. We know how to accomplish do these things, but we need models that allow companies to know how many nests to treat or eagles to rehabilitate to offset their permitted take.
AWWI now has experience working with expert teams on the three models we’ve developed, so we are well positioned to build additional models and add to the toolbox of options for companies to choose from to best meet their permitting needs while maximizing eagle conservation.
Learn more about AWWI’s Eagle Program: Contact Taber Allison at tallison@awwi.org