Texas Horned Lizards on the Texas High Plains

Allison, Pamela S.

P.O. Box 812

Canyon, Texas


Cepeda, Joseph C.

P.O. Box 162

Canyon, Texas

During the years 2006-2014, we observed a population of Texas Horned Lizards (Phrynosoma cornutum) in the Texas Panhandle – without the use of tracking devices, which (in retrospect) would have impaired nesting activities of adult females in the hard caliche High Plains surface. Daily activities of two adult females, their nest constructions, progeny, and longevity became the primary focus; however, we weighed and measured lizards of all ages, including hatchlings as they emerged from nests. Adult females double clutched in a summer. Although Pogonomyrmex rugosus beds are available to these lizards, their main diet is Crematogaster sp. Subadults and hatchlings were never seen to feed on Pogonomyrmex sp., although adults did when it seemed (to us) advantageous that they gain weight quickly, such as females immediately after nesting. Seasonally, adult males emerged from hibernation first and were the shortest lived; genders and age brackets of lizards active above ground seemed to minimize competition for food. The greatest diversity of predators on these lizards was observed in the summer with the highest number of nests and hatchlings.