The U.S. Fish and Wildlife Service commonly relies on habitat suitability maps when developing Species Status Assessments (SSAs) that inform listing decisions for at-risk species under the ESA. Habitat suitability models (also called species distribution models, or SDMs) predict and map where species and habitat occur, and how these distributions are changing over time. Conservation planning efforts rely on information about the spatial distribution of species and their habitats to prioritize areas for management.

The researchers worked with 30 species experts to improve the models and gathered a comprehensive dataset of over 70,000 species location records to build habitat models. The experts helped the research team prioritize which environmental variables – such as fire frequency and canopy cover – to evaluate as predictors of suitability. The models also capture variation in habitat suitability across the range of each species, thus allowing stakeholders to visualize the spatial relationships among high quality and lower quality habitat.

Habitat suitability maps have already informed SSAs for the gopher tortoise and southern hognose snake and will be used to inform additional SSAs in the future. Regardless of final listing decisions, these species are declining across much of their ranges and are priorities for conservation planning for states and other partners across the Southeast. Partners may be interested in using these products for several purposes:

• Assess suitability at a local site known to be occupied by a species and tailor site-level management (e.g., increased use of prescribed fire)
• Prioritize survey efforts in areas of high suitability without known or documented species records (e.g., on private lands)
• Use the distribution of areas suitable for one or more species on protected or unprotected lands to identify priority areas for management, land acquisitions, or other strategies

Other habitat suitability models have been developed for these species and could be consulted alongside these new models for conservation planning. A few examples of other existing datasets are:

• Habitat models for 10 at-risk species, including the gopher frog, striped newt, and southern hognose snake developed by state natural heritage programs in a South Atlantic Landscape Conservation Cooperative-funded project, and
• A pilot project to refine a subset of Southeast species models based on NatureServe’s forthcoming Map of Biodiversity Importance capturing over 2,000 at-risk species.

Full details about the habitat suitability model work will be available in a paper currently being peer-reviewed (available online early). The final version will be online in about one month. In the meantime, listen to this project overview.

The ONB features articles from Cooperative Fish and Wildlife Research Units across the country. Working with key cooperators, including WMI, Units are leading exciting, new, fish and wildlife research projects that we believe our readers will appreciate reading about. Story by Brian Crawford, Postdoctoral Research Scientist, USGS Georgia Cooperative Fish & Wildlife Research Unit at the University of Georgia