PRESENCE-ONLY PREDICTION (MAXENT) AS A TOOL TO DIRECT SURVEYS AND MITIGATION OF CALIFORNIA NEWT ROAD MORTALITY | |||
| Anna L Petrosky; San Jose State University, Swaim Biological Inc; a.lavelle.p@gmail.com; Rachel O'Malley | |||
The California newt (Taricha torosa) is listed as a State Species of Special Concern south of the Salinas River due to habitat degradation and loss. In the San Francisco Bay Area, the work of several citizen scientist groups indicates that road mortality may be a significant threat outside of their protected range. Only one published study has specifically investigated this risk, and found near-term extirpation was likely at a location thoroughly documented by citizen scientists. In order to understand the extent of this threat, additional surveys are needed. We conducted roadkill surveys at two novel sites (Guadalupe and Almaden Reservoirs, Santa Clara County) during the 2024-2025 migration season and used this data alongside observations by the Lexington Reservoir Newt Patrol to train a roadkill distribution model using Presence-Only Prediction (Maxent) in ArcGIS Pro. Models generated using rasters with 30m resolution showed high probabilities of roadkill presence at mortality hotspots in the survey data and identified several unsurveyed locations with moderate to high probabilities of roadkill presence. These included residential streets, roads bordering county parks and a fire road frequented by mountain bikers. Model predictions offer opportunities for ground truthing and potentially subsequent mitigation such as road improvements and trail closures. | |||
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