The flat-tailed horned lizard (Phrynosoma mcallii) has the most limited distribution of any horned lizard species in the United States. It is found in the deserts of California, Arizona, and Mexico, with its California range limited to the low-elevation deserts within the Imperial and Coachella Valleys, including the desert habitats of eastern San Diego County.

These areas have been impacted by urban and agricultural development, energy development, habitat degradation, and off-road vehicle activity. The rapid expansion of these human activities coupled with substantial development have had devastating consequences for this species.

Using data from the online Amphibian and Reptile Atlas of Peninsular California, our scientists are able to make efforts to help with the conservation of this charismatic lizard.

Researchers have found flat-tailed horned lizards living on finely packed sandy soils, Aeolian sands, gravel flats, barren clay soils, and mud hills. Creating a species distribution model using records of where the animal has been observed, which includes data from The Nat’s historic collections, scientists are able to better understand where the animal may live. This, in turn, helps us identify where conservation efforts should be prioritized.

What is a species distribution model?

Conserving species and habitats depends largely on knowing where they occur. Scientists conduct field inventories to map the distribution of plants and animals, but it’s impossible to cover the entire landscape, so full distributions of species are often unknown. Advances in environmental data gathering allow for comprehensive mapping of a species habitat using an approach called species distribution modeling. This is an innovative method that combines species observation data with environmental predictors to better understand the niche, identifying areas in which the species is likely to occur.

Species distribution modeling has helped our scientists understand the environmental factors that shape patterns of biodiversity and learn what the lizard needs to survive. This information is then expanded to help predict the overall habitat in which the species lives, which in turn can help landscape-level conservation planning.

Posted by The Nat on October 18, 2019