The Texas horned lizard (Phrynosoma cornutum) is a harmless spikey-bodied reptile called horned lizard. It is the largest and most widely distributed of the 14 species of horned lizards in the western United States and Mexico.
The Texas horned lizard has characteristic horns spanning across its body with the two largest crowning its head, two more on its brows and jawline respectively, as well as lines of spikes spanning the lateral parts of the torso and dorsal ridges of the back. Coloration varies depending on the environment in order to blend in with the color of the ground, ranging from a yellow or reddish-brown for deserts to a tannish brown for prairies. They also have dark lines that span from the eyes to the tip of the horns and a characteristic solid white line with a few black circular splotches on either side.
Texas horned lizards range from Colorado and Kansas to northern Mexico (in the Sonoran desert), and from southeastern Arizona to Texas. They may also be native to Louisiana and Arkansas. Also, isolated, introduced populations are found in the Carolinas, Georgia, and northern Florida. These horned lizards live in open dry areas such as deserts, prairies, dunes, playas, low valleys, and foothills with grass or shrub cover.
Despite their fierce appearance, Texas horned lizards are extremely docile creatures. They lead a solitary life and interact with each other only during the mating season. They are diurnal and spend their time feeding, resting in the shade, or sunbathing along the side of roads or other open, rocky areas. At night, they bury themselves in the sand and sleep. During the winter Texas horned lizards hibernate under soil or foliage. These horned lizards prefer to move very little, however, they can move quite fast if they feel a predator is in the area, and dart into thick grass and foliage to escape. Horned lizards are also excellent diggers, and can quickly burrow underground to escape threats. Their coloration generally serves as camouflage against predation, however, when threatened by a predator, a horned lizard puffs up and appears very fat, which causes its body scales to protrude, making it difficult to swallow. Texas horned lizards also have the ability to squirt an aimed stream of blood from the corners of the eyes and sometimes from their mouth for a distance up to 5 ft (1.5 m). They do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the eyelids. This not only confuses predators, but also the blood is mixed with a chemical that is foul-tasting to canine predators such as wolves, coyotes, and domestic dogs. This novel behavior is generally observed to be very effective in defense; however, it appears to have no effect against predatory birds.
Texas horned lizards are carnivores (myrmecophagous, insectivores). Most of their diet is made up of Harvester ants, though they supplement these with termites, beetles, and grasshoppers.
Texas horned lizards breed after hibernation from mid-April and until mid-June. Females dig burrows and lay 14-37 eggs which are incubated for about 6 weeks. Hatchlings are independent immediately after birth and become reproductively mature when they are 2 years old.
Texas horned lizards have disappeared from almost half of their geographic range. Population declines are attributed to the loss of habitat, human eradication of the ant populations upon which the lizards prey, displacement of native ant populations by invading fire ants, and predation by domestic dogs and cats. Texas horned lizards also suffer from the collection for the pet trade and in some areas, road mortality poses another important threat.
The IUCN Red List and other sources don’t provide the number of the Texas horned lizard total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
About 70% of the Texas horned lizard's diet is made up of Harvester ants; this way they keep ant populations under control. In turn, Texas horned lizards are prey species to local predators.
