Assessing Traffic Threats for Amphibian and Reptile Species of Greatest Conservation Need on Texas Roadways: Final Report

Authors: D.K. Walkup, K.L. Skow, T.J. Hibbitts, W.A. Ryberg and R.R. Lopez

Transportation planning is complicated by natural resource and environmental issues, and project planning and delivery are more efficient when environmental impacts are known early. Many environmental impacts involve state and federally listed threatened and endangered (TE) species. Wildlife-vehicle collision (WVC) data can improve environmental impact assessments for TE species. Accurate WVC data has been collected for amphibian and reptile species on Texas roadways since 2012, in the form of observations in the “Herps of Texas” project on the citizen science platform iNaturalist. These data were used to create a database of species of greatest conservation need (SGCN) recorded and verified in the state that was joined with Texas road traffic data from the Texas Department of Transportation (TxDOT) and used to evaluate SGCN species presence and mortality on and near roads. This report summarizes trends observed from 11,527 Research Grade quality records of 62 SGCN species used to characterize the importance of traffic volume in predicting mortality throughout the state for all SGCN on or near roads, including the federally endangered Houston Toad (Anaxyrus houstonensis), federally threatened Louisiana Pinesnake (Pituophis ruthveni), as well as the Crawfish Frog (Lithobates areolatus), Spot-tailed Earless Lizards (Holbrookia lacerata and H. subcaudalis), Texas horned lizard (Phrynosoma cornutum), Western Massasauga (Sistrurus tergeminus), Rio Grande Cooter (Pseudemys gorzugi), Western Chicken Turtle (Deirochelys reticularia miaria), Alligator Snapping Turtle (Macrochelys temminckii), and Texas Tortoise (Gopherus berlandieri).

 

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