Habitat Use of Texas Horned Lizards in Southern Texas

Abstract

Microhabitat characteristics for the Texas horned lizard (Phrynosoma cornutum) were qualified from information gained from radio-tracking in Duval County, Texas. Microhabitat characteristics were assessed from known locations of lizards and random locations and included soil pH, soil particle size distribution, soil organic content, percent herbaceous vegetation, vegetation height, percent bare ground, vegetative basal area for bunch grasses, plant stem density, soil temperature, percent canopy cover, percent grasses, and percent forbs. Lizards (n = 16) disproportionately used the range of values for 11 of the 14 (soil pH, soil particle size distribution, soil organic content, percent bare ground, plant stem density, soil temperature, percent canopy cover, percent grasses, and percent forbs) microhabitat characteristics from their availability. Microhabitat characteristics recorded at bedding sites were used pro rata to availability. Soil moisture at bedding sites average 2.2% during the months July through October. Lizards would not bury themselves in soil for several days after precipitation; instead the bases of trees and bunch grasses were used as bedding sites.