A Habitat Suitability Analysis of Texas Horned Lizards in Texas and New Mexico

Abstract

The Texas Horned Lizard (Phrynosoma cornutum) is a state-protected lizard native to the American Southwest. To rebuild the Texas Horned Lizard population, they are bred in captivity and released into the wild. Identifying factors that impact habitat suitability is vital to finding the proper areas for release and reintroduction. Environmental and human factors were examined in Texas and New Mexico counties native to the Texas Horned Lizard, as well as counties without known sightings, to determine which factors most impact habitat suitability. Four statistical and geospatial software packages were used to map, analyze, and evaluate 24 potential variables and it was discovered that elevation, road density, natural gas pipeline density, seasonal rainfall, land use category, and proximity to Red Harvester Ants are all statistically significant to Texas Horned Lizard habitat suitability at a 95% confidence level. Texas Horned Lizards are most prevalent in counties with low elevation, high percentage of open water or snow, low precipitation levels, and native habitats for Red Harvester Ants. Horned Lizards are also less prevalent where road density or natural gas pipeline density is high. No significant difference was detected in habitat suitability relative to Imported Fire Ants as suggested in previous studies. To protect viable environments for Texas Horned Lizard reintroduction, pipeline and road construction should be limited in the most suitable regions: eastern and southern New Mexico, the southern Gulf Coast, the Texas Panhandle, Edwards Plateau, and along the Rio Grande.