EVS staff have developed a spatially explicit, individual-based model (IBM, also known as an agent‑based model) to examine the cumulative impacts of wind energy development on populations and habitat of the greater sage-grouse (Centrocercus urophasianus), a species whose population has declined significantly, is considered near threatened by the International Union for Conservation of Nature, and has been considered for listing under the U.S. Endangered Species Act. Model development was initiated with funding from DOE’s Wind and Water Power Program.

Concern over the sustainability of sage-grouse populations in the face of increasing development has led to widespread restrictions on development in the species’ core areas, but an incomplete understanding of the birds’ response to the development of wind farms and other structures could lead to unnecessary or ineffective restrictions. This EVS work is intended to facilitate smart development that minimizes impacts by synthesizing available information into a predictive model.

The sage-grouse has a complex life history that includes seasonal migrations to meet its needs. Local disruption of any part of the annual cycle could result in long-term impacts over a wider portion of the species’ range. To improve understanding of the possible effects of wind energy projects and other impacts on populations, the EVS model incorporates the species’ requirements and movements.

The model was developed using Albany County, Wyoming, as a case study. Albany County supports important populations of greater sage‑grouse and has high potential for wind energy development. This early model prototype demonstrated the utility of the approach in assessing direct, indirect, and cumulative effects by modeling changes in habitat suitability, reproduction, and survivorship of individual birds. With this tool, users can determine proximate causes of sage-grouse population changes (e.g., changes in seasonal habitat suitability, survivorship, and reproduction). This information can be used to design focused mitigation strategies that address underlying impact drivers.

This modeling approach could be applied to evaluate impacts of other developments on sage-grouse or other wildlife species. Future work will focus on incorporating climate change scenarios and natural hazard risks into the model, and developing the model into a fully functioning, user-friendly tool that land management agencies, planners, developers, and other stakeholders can use to evaluate the effects of energy development on important wildlife species.