Geothermal energy production adversely affects a sensitive indicator species within sagebrush ecosystems in western North America

Growing demand for renewable energy has resulted in expansion of energy infrastructure across sagebrush ecosystems of western North America. Geothermal power is an increasingly popular renewable energy source, especially within remote areas, but little is known about the impacts it may have on local wildlife populations. Investigations are warranted given similarities to more conventional surface disturbance activities with well-documented impacts. Using a novel 2-pronged analytical approach, we estimated effects of geothermal energy production activities (hereafter, geothermal) on populations of greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a species of high conservation concern. First, we applied a before-after-control-impact paired series design at two geothermal sites in Nevada, USA, to estimate absence rates of male sage-grouse from lek sites (breeding grounds) and changes in predicted apparent abundance (lambda) in relation to geothermal energy infrastructure. We then estimated effects of geothermal energy infrastructure and other environmental covariates on demographic rates. We found lambda declined-24 % within 5 km of geothermal sites, while lek absence rates (e.g., indicating local extirpation) increased by-730 % within 2 km. Our demographic models revealed decreased nest survival in association with proximity to geothermal infrastructure, reduced topographic impedance surface (TIS; a proxy for sound and light dispersion emanating from geothermal infrastructure), and increased density of common ravens (Corvus corax), an effective nest predator. Models also estimated decreases in adult survival in relation to TIS. Finally, we applied population matrix models within a quantitative decision support framework to help guide locations for future geothermal development that balance the need for domestic energy production while minimizing adverse effects on wildlife populations.

Automated summary

The growing demand for renewable energy has led to the expansion of energy infrastructure in sagebrush ecosystems of western North America. Geothermal power, a popular renewable energy source, might have negative impacts on local wildlife populations. This study found that geothermal energy production activities resulted in a decline in sage-grouse populations and nest survival, as well as an increase in ravens, a nest predator.