Refining species range maps for improved implementation of the ESA

Refining species range maps for improved implementation of the ESA


The Endangered Species Act (ESA) is often considered the strongest law in the world for protecting imperiled species. However, there are inefficiencies that limit its effectiveness, including limitations in the resolution and accuracy of spatial data. For many species, available maps and geospatial data provide only coarse species ranges, such as indicating a species’ presence at the level of a county or state, creating a false impression that the species occupies a larger area than it does. We are working with a multi-sector coalition to develop refined range maps for ESA-listed species. Through systematic collection of spatial data and careful consideration of life history and suitable habitat, we are synthesizing information from a variety of publicly available data sources and community science databases to refine ranges using species distribution models and models using only species occurrence records. For species with very narrow distributional extent, we are manually delineating ranges. This project has led to developing new tools to foster mapping collaboration and feedback within the scientific and conservation practitioner community to further refine species ranges. Further, the outputs will help researchers understand the unique and diverse species and habitats that can be found in limited areas throughout the U.S. The results of this work will provide an avenue for more efficient allocation of resources for ESA planning, monitoring, and compliance.

Asilomar Conference Center, Monterey, CA
Mae Lacey
Conservation GIS Analyst

As the Conservation GIS Analyst in the Center for Conservation Innovation, Mae provides support and leadership for geospatial product development across Defenders.