Bear Range Mapping

In the most recent range maps, FWC biologists used objective, data-driven methods to map Florida black bear range state-wide. They used multiple data sources and subsampling techniques to reduce potential biases and sophisticated spatial analyses to draw range boundaries and differentiate several levels of occurrence.

Bear researchers first collect location data from multiple sources across the state in a 10-year period (most recently, 2009-2018). Each data point includes a known bear location and date. Datasets include:

FWC Bear Management Data

• • Reported bear mortalities (e.g., vehicle strikes)
  • Bear-related incidents (e.g., human-bear conflicts, injured bears)
  • Orphaned cubs

FWC Bear Research Data

• • Genetic samples collected for mark-recapture abundance studies

Opportunistic Observations

• • Sightings by wildlife professionals (e.g., FWC staff, reported by other agencies to the Florida Natural Areas Inventory)
  • Sightings by members of the public (e.g., FWC Bear Sightings Registry, iNaturalist)

After data collection, researchers inspect data to remove duplicates or errors and to subsample to reduce biases. They then plot occurrences on a map and conduct spatial analyses. To define areas of Frequent and Common bear range, they use a “kernel density estimator” (KDE) which identifies areas of highest bear occurrence based on the number and distribution of bear occurrences. To define Occasional bear range, they use a “concave hull” model, which outlines areas of general bear occurrence coarsely. The remainder of Florida not included within the Frequent, Common, or Occasional range delineations is considered Rare bear range.

FWC research methods produce detailed, reproducible, and reliable bear range maps to inform the FWC Bear Management Program, Florida residents, and any interested stakeholder. Maps are both visually and quantitatively comparable over time so that trends in range extent can be identified.