The Texas horned lizard is a stocky, short-tailed lizard with several large “horns” protruding from the back of the head. Its general color is tan, grayish brown, or reddish brown. There are two large, dark brown spots behind the head and a series of brown markings on the back. A white or yellow line extends down the center of the back. Scales on the limbs, sides, and tail are large and pointed; the head is heavily armored with large scales, some modified to form “horns.” The belly is white with several small gray spots.
These lizards are harmless to people. They defend themselves by puffing up their bodies with air to look larger, or they can eject a small amount of blood from the inner corners of each eye to confuse a predator.
Adult total length: 2½–4 inches; occasionally to 7 inches.
Limited to the far southwestern corner of the state. The overall range is to the west and southwest of Missouri.
Habitat and Conservation
The active season for Texas horned lizards in Missouri is from April to early October.
Texas horned lizards prefer open, dry areas with loose or sandy soil and plenty of rocks. This species is active by day as long as the sun is out and the temperature is high. When inactive, the Texas horned lizard seeks shelter just below the surface of the soil.
Horned lizards are occasionally seen along the edges of dirt or gravel roads. They are best observed during sunny mornings when they bask in open areas.
Horned lizards eat primarily ants, especially harvester ants (Pogonomyrmex spp.), but occasionally eat other insects (beetles and grasshoppers) and spiders.
A species of conservation concern in Missouri. The Texas horned lizard once lived in several southwestern counties, but it is now limited to just a few counties bordering with Kansas, Oklahoma, and Arkansas.
In Missouri, this species is active from April to early October. Courtship and breeding have not been observed in Missouri. Breeding presumably takes place soon after the active season begins, probably in May and June. Females produce an annual clutch of 13–49 eggs, with an average of about 23–25 eggs. The female digs a nest in loose soil or under large rocks in which the eggs are deposited. The eggs hatch within 1 or 2 months. Hatchlings are only about 1¼ inches long. Texas horned lizards have been known to live up to 10 years of age in captivity.
This interesting lizard offers several marvels for human observers. It can squirt blood from its eyes as a defense, and it can also collect rainwater from its back. However, because of its specialized diet and need for high temperatures, this species is very difficult to keep in captivity.
Another reason for not keeping them as pets is that the Texas horned lizard is listed as a species of conservation concern in Missouri. In our state, this species occurs only in extremely low numbers and has little suitable habitat.
This lizard has been very popular in the pet trade for many decades, and this has resulted in overcollecting and declines throughout their range. Today, most southwestern states no longer allow this species to be collected.
There are only seven documented reports of this lizard in the state, with the most recent capture of a juvenile being found in July 2013, in Jackson County. A number of Missourians have brought live specimens from Texas or Oklahoma while returning from vacation trips and released them near their homes in several parts of this state. It is unknown if natural populations occurred in Missouri or if reported individuals are released pets primarily found in urban areas.
A lizard that specializes in eating ants naturally helps to limit ant populations.
Unlike many other species of lizards, the Texas horned lizard is not capable of breaking off its tail when grabbed by a predator. They rely on their cryptic coloration, their ability to burrow under the soil, their quick sprinting and freezing-motionless behavior, and their unusual habit of squirting blood to avoid and escape predators. They can squirt a few drops of blood from the corners of the eyes when captured. This can help them escape capture by dogs, coyotes, foxes, and predatory birds.
This species has several adaptations that help it to survive in dry, hot environments. For example, although it can obtain water by licking dew from vegetation, it has evolved the ability to collect rainwater along its back. During a rain, a horned lizard will arch its back upward, flatten its body, lower its head, and drink the water as it collects along its lips. Between the scales on the back are specialized, microscopic channels that help direct rainwater to the downward-pointing head.
Missouri has two species — the Texas horned lizard and the prairie lizard — in the family Phrynosomatidae (the spiny and sand lizard family). This family consists of 9 genera with 148 species ranging from southern Canada, most of the United States, and through Central America. Most of these lizards prefer dry, open habitats with rocky outcrops or loose soils. Like the family containing the eastern collared lizard, members of this family have teeth located on the inner surface of the lower jaw and communicate by head bobbing and body pushups. These gestures are used by males to defend their territories and court females. Within the subgroup called horned lizards, there are 17 species. These are small lizards with flat, stout bodies and short tails that prefer loose, sandy soils. Most are known for their ability to squirt blood from the eyes when stressed, and some species are distasteful to predators due to chemical properties from their ant prey.