Under proposed Alternatives 3 and 4 in the draft Environmental Assessment for the proposed rule (Permits for Incidental Take of Eagles and Eagle Nests), wind facilities would be eligible for a general permit or a specific permit based, in part, on eagle abundance data. This map of the coterminous U.S. shows where projects would be eligible to self-certify for a general permit if they meet all of the criteria, or apply for a specific permit. Existing projects that are only eligible for specific permits may be determined to qualify for a general permit upon Service review of their permit application. See the Federal Register Notice for information about submitting comments on the proposed rule and draft environmental review.

Permit eligibility zones are based on eBird relative abundance estimates for bald eagles and golden eagles throughout the coterminous United States at 8 km2 resolution for each of five periods (breeding, fall, migration, spring, winter). Using multiple seasons of data provides better measures of relative abundance for mapping purposes (Johnston et al. 2020), and our goal was to identify locations with high relative abundance of eagles in any one season.

For each eagle species we evaluated non-zero relative abundance data for each season using custom R scripts in Program R (R Core Team 2021). We identified cells that had relative abundance values in each season that were at or above the relevant quantile threshold value. We combined these species-specific, seasonal layers into a single layer that indicates cells that did not exceed the relative abundance thresholds in any season and cells that exceeded one or more threshold. We then created maps of the permit eligibility zones (i.e., grid cells that did not exceed the relative abundance threshold in any season) for several scenarios for each eagle species. This map includes a combined proposed general permit zone consisting of areas where golden eagle abundance is 50% or less than golden eagle abundance elsewhere in the lower 48 states within each season and bald eagle abundance is 95% or less than it is elsewhere in the lower 48 states in each season.

This raster layer uses an equal-area sinusoidal projection that is used by eBird status and trend products, including relative abundance data (this projection is also used for NASA MODIS data). Note: We advise that users reproject any layers they wish to conduct spatial overlay analyses with into the same sinusoidal projection as this layer to ensure the most accurate geospatial representation of the data. Cell values of 0 indicates cells where a wind project may be eligible for self-certified general permit if other qualification criteria are met under the proposed regulation. Cell values of 1 indicates cells where a wind project would be eligible for a simplified specific permit.

Additional technical details about map development can be found in Appendix A of the draft Environmental Assessment for the Proposed Eagle Incidental Take Rule revision.