Estimating offsets for avian displacement effects of anthropogenic impacts

Science Center Objects

The avian-impact offset method (AIOM) quantifies the amount of habitat needed to provide equivalent biological value for birds displaced by energy and transportation infrastructure. The AIOM can be applied in situations where avian displacement (i.e., behavioral avoidance) requires compensatory mitigation. The AIOM is based on the ability to define five metrics: impact distance, impact area, pre-impact density, percent displacement, and offset density. Our work provides four products: 1) displacement rates from wind-energy facilities for waterfowl and grassland birds, 2) an explanation and demonstration of the AIOM using examples for wind and oil infrastructure, including cases in which the biological value of offset habitat (i.e., habitat acquired to fulfill mitigation requirements) is similar to the impacted habitat and when biological value is dissimilar, 3) a worksheet for AIOM users to apply to their own projects, and 4) a geospatial AIOM Decision Support Tool that automates Geographic Information System processes for identifying biologically equivalent habitats for mitigation fulfillment, as well as for forecasting mitigation costs of proposed developments.