Horny Toad Lizard Facts

Scientific Name: Phrynosoma

Texas horned lizard
Texas horned lizard or horny toad.

texcroc / Getty Images

The horny toad is actually a lizard (a reptile) and not a toad (an amphibian). The genus name Phrynosoma means "toad bodied" and refers to the animal's flattened, round body. There are 22 species of horned lizard and several subspecies.

Fast Facts: Horny Toad Lizard

  • Scientific Name: Phrynosoma
  • Common Names: Horny toad, horned lizard, short-horned lizard, horntoad
  • Basic Animal Group: Reptile
  • Size: 2.5-8.0 inches
  • Lifespan: 5-8 years
  • Diet: Carnivore
  • Habitat: Deserts and semi-arid parts of North America
  • Population: Decreasing to stable
  • Conservation Status: Least Concern to Near Threatened

Description

The horny toad has a squat, flattened body and a blunt nose like a toad, but its life cycle and physiology are that of a lizard. Each species is distinguished by the number, size, and arrangement of the crown of horns on its head. The lizard has spines on its back and tail that are modified reptile scales, while the horns on its head are true bony horns. Horny toads come in shades of red, brown, yellow, and gray and can change their color to a certain extent to camouflage themselves against their surroundings. Most horny toads are less than 5 inches long, but some species reach 8 inches in length.

Habitat and Distribution

Horny toads live in arid to semi-arid regions of North America, from southwestern Canada through Mexico. In the United States, they occur from Arkansas west to California. They live in deserts, mountains, forests, and grasslands.

Diet

The lizards are insectivores that prey primarily on ants. They also eat other slow-moving ground-dwelling insects (sow bugs, caterpillars, beetles, grasshoppers) and arachnids (ticks and spiders). The toad either slowly forages or else waits for prey and then catches it with its sticky, long tongue.

Horny toad with extended tongue
Horny toads use their sticky tongues to catch prey.  ebettini / Getty Images

Behavior

Horny toads feed early in the day. When ground temperature becomes too hot, they seek shade or dig themselves into the ground to rest (aestivation). In the winter and when temperatures drop in the evening, the lizards brumate by digging into the ground and entering a period of torpor. They may cover themselves completely or leave only their nostrils and eyes exposed.

Horny toads have interesting and distinctive methods of self-defense. In addition to camouflage, they use their spines to make their shadows blurry and to deter predators. When threatened, they puff up their bodies so their large size and spines make them harder to swallow. At least eight species can squirt a directed stream of blood from the corners of their eyes up to 5 feet. The blood contains compounds, presumably from the ants in the lizard's diet, that are distasteful to canines and felines.

Reproduction and Offspring

Mating occurs in late spring. Some species bury eggs in the sand, which incubate for several weeks before hatching. In other species, eggs are retained in the female's body and the young hatch shortly before, during, or after egg-laying. The number of eggs varies by species. Between 10 and 30 eggs may be laid, with an average clutch size of 15. The eggs are about a half inch in diameter, white, and flexible.

Hatchlings are 7/8 to 1-1/8 inches long. They have horns like their parents, but their spines develop later. The hatchlings receive no parental care. Horny toads reach sexual maturity when they are two years old and live between 5 and 8 years.

Juvenile horned lizard
Juvenile horny toads resemble their parents, but are smaller in size.  Design Pics / Getty Images

Conservation Status

Most horny toad species are classified as "least concern" by the IUCN. Phrynosoma mcallii has a conservation status of "near threatened." There is insufficient data to evaluate Phrynosoma ditmarsi or the Sonoran horned lizard, Phrynosoma goodei. Some species' populations are stable, but many are decreasing.

Threats

Humans pose the greatest threat to horny toad survival. The lizards are collected for the pet trade. In areas near human habitation, pest control threatens the lizard's food supply. Horny toads are also affected by fire ant invasions, as they are selective about the ant species they eat. Other threats include habitat loss and degradation, disease, and pollution.

Sources

  • Degenhardt, W.G., Painter, C.W.; Price, A.H. Amphibians and Reptiles of New Mexico. University of New Mexico Press, Albuquerque, New Mexico, 1996.
  • Hammerson, G.A. Phrynosoma hernandesi. The IUCN Red List of Threatened Species 2007: e.T64076A12741970. doi:10.2305/IUCN.UK.2007.RLTS.T64076A12741970.en
  • Hammerson, G.A., Frost, D.R.; Gadsden, H. Phrynosoma mcallii. The IUCN Red List of Threatened Species 2007: e.T64077A12733969. doi:10.2305/IUCN.UK.2007.RLTS.T64077A12733969.en
  • Middendorf III, G.A.; Sherbrooke, W.C.; Braun, E.J. "Comparison of Blood Squirted from the Circumorbital Sinus and Systemic Blood in a Horned Lizard, Phrynosoma cornutum." The Southwestern Naturalist. 46 (3): 384–387, 2001. doi:10.2307/3672440
  • Stebbins, R.C. A Field Guide to Western Reptiles and Amphibians (3rd ed.). Houghton Mifflin Company, Boston, Massachusetts, 2003.