The name "Phrynosoma " means "toad body." In common language the short-horned
lizard and its relatives are referred to as "horned toads" even though
these animals are really reptiles, not amphibians. The only "horned toad"
in South Dakota, the
Known throughout most of the high, arid plains from Kansas to Canada
and into the adjacent eastern Rocky Mountains, the
Tolerant of the cold of the northern Great Plains and the higher mountain
elevations, the short-horned lizard prefers open, flat
areas where it forages for ants, grasshoppers, and other small invertebrates . Its well-camouflaged coloration make it an
effective predator. The lizard hunts during the day from late spring to fall, when cold temperatures force it to burrow under
ground or seek refuge in rodent burrows. Horned lizards have excellent eye sight and rely on movement to detect prey; they
pay no attention to stationary objects. While stalking moving prey, horned lizards twitch their tail, much as a cat does when
watching birds. Before striking, they watch their prey with their heads cocked to one side. With a flick of a tongue and the
snapping of jaws the prey is captured. Ants are their most common prey.
Theses lizards can survive in areas with little water since their nitrogen
wastes are excreted as uric acid, the most
water-conserving form of waste. Their habit of burying in soil during hot, dry spells also aids in water retention.
At two years of age, the females reach sexual maturity and give birth
to an average of 14 to 17 young. The short-horned
lizard is an ovoviviparous species, that is, the females produce eggs but fertilization is internal and the eggs develop within
As with most of its horned lizard relatives, the short-horned lizard
exhibits the ability to eject blood from the corner of its
eyes when handled roughly. Some authorities think this may repel predators, while others feel it serves to regulate body
temperature in some manner. Whatever the case, it startles people to see blood mysteriously appear and it probably has
helped some lizards escape.
The short-horned lizard has played an important role in the food chain
of the northern Great Plains and shortgrass prairies.
This lizard contributes to a healthy, biologically diverse ecosystem by preying on a wide range of invertebrates and, in turn,
becoming a food source for larger predators, such as hawks and snakes.
The short-horned lizard is listed as rare in South Dakota and, as such,
is protected from collection, capture, and disturbance.
Population numbers are monitored and habitats protected through the South Dakota Natural Heritage Program. Threats
include the loss of habitat to development and agriculture, the loss of prey species from agricultural practices, and human
Invertebrates - animals without a backbone, such as worms and
Ovoviviparous - a reproductive behavior in which females produce eggs that develop within the female.
Uric acid - the driest form of waste that is produced by kidneys of vertebrates.
References and Selected Resources For Teachers
Baxter, G.T. and M.D. Stone. 1980. Amphibians and Reptiles of Wyoming.
Wyoming Game and Fish Department.
Milne, Lorus J. and Margery J. Milne, 1950. Notes on the behavior of horned toads. American Midland Naturalist, 44(3) p.
Reeve, W.L. 1952 Taxonomy and distribution of the horned lizards genus Phrynosoma . University Kansas Sci. Bull.,
Smith, Hobart M. 1956. Handbook of Amphibians and Reptiles of Kansas. Miscellaneous Pub. No. 9. University of Kansas,
Museum of Natural History.
Stebbins, Robert C. 1966 A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin Co. Boston, MA.
Dr. Erika Tallman, Northern State University, Aberdeen, SD. 1996.
Steve Thompson, South Dakota Department Game, Fish and Parks, Pierre, SD.
Steve Thompson, South Dakota Department of Game, Fish and Parks, Pierre, SD.
Publication of the Short-horned Lizard fact sheet was funded
by the South Dakota Department of Game, Fish, and Parks,
Division of Wildlife, Pierre, SD.