Encyclopedia of the Great Plains

AMPHIBIANS AND REPTILES

Amphibians and reptiles, collectively called herptiles, are ectothermic or "cold-blooded" vertebrates. Amphibians include frogs and toads, salamanders, and caecilians, the latter not represented in the Great Plains. Reptiles technically do not constitute a distinct biological group, but the term is used here in the vernacular sense to refer to turtles and tortoises, lizards, snakes, and alligators and crocodiles. Amphibians and reptiles, except for rattlesnakes, are not typical icons of the Plains, yet more than 150 different species occur in some part of the region. This number represents about 30 percent of the species occurring in North America. No herp species is limited to the Great Plains, but many species reach one of their distributional limits here. More herps occur in the southern part of the region.

Only eleven species of salamanders extend into the Great Plains, mostly along its eastern periphery. Of these, seven species are restricted to southeastern Kansas, and only Ambystoma tigrinum, the tiger salamander, is found throughout the Great Plains. This salamander spends much time underground in burrows and surfaces to feed or reproduce when environmental conditions are favorable.

There are thirty-two species of frogs and toads in the Great Plains, including three that are especially prominent. One species, Spea bombifrons, the Plains spadefoot, occurs in all states and provinces of the Great Plains. This species depends on temporary ponds formed after spring and summer thunderstorms. Well known for its rapid tadpole development, it can breed in roadside ditches. Bufo cognatus, the Great Plains toad, is abundant and forms large breeding choruses after thunderstorms. The shrill call of thousands of these toads from a "buffalo wallow" can be heard for several miles. A third species, Rana blairi, the plains leopard frog, is restricted to the central grasslands, extending from the Great Plains into the tallgrass prairie peninsula as far east as western Indiana. Like other leopard frogs, it is dependent on permanent ponds and lakes because its larvae require several months for metamorphosis.

Of the nineteen species of turtles in the Great Plains, none occurs in all states and provinces. The snapping turtle, Chelydra serpentina, occurring in larger ponds, lakes, or rivers, is found throughout the Great Plains except for Alberta. The painted turtle, Chrysemys picta, is widely distributed across the Plains except for Texas. This is one of the few herps of the region whose distribution is more northern than southern. It frequents permanent ponds and lakes. Terrapene ornata, the ornate box turtle, is a common terrestrial species, especially in sandy soils of the Southern Plains and as far north as South Dakota. This species is often associated with mammal burrows, such as those of prairie dogs, where it will retreat to overwinter.

The thirty-three species of lizards have a distinctly southern distribution: all but one occur in Texas, and none are found entirely throughout the region. Phrynosoma douglassi, the short-horned lizard, is the most widespread species, occurring in all states and provinces except Manitoba, Kansas, and Oklahoma. However, this species frequents the plateaus along the Rocky Mountains rather than being a true Plains species. The distribution of Eumeces septentrionalis, the prairie skink, is remarkably coincident with the tallgrass prairie from eastern Texas to Manitoba, although its distribution extends eastward into Minnesota and Iowa. The Great Plains skink, Eumeces obsoletus, is distributed from the desert Southwest into the Southern Plains and as far north as Nebraska and Wyoming.

Snakes are the most numerous herptiles with fifty-nine species occurring in some part of the Plains. Fifty of these species live on the Plains of Texas. Three species, the plains garter snake (Thamnophis radix), common garter snake (Thamnophis sirtalis), and western hognose snake (Heterodon nasicus), inhabit all states and provinces of the region. Garter snakes are semiaquatic, occurring along streams and ponds, whereas the hognose is common in open, especially sandy, prairies. The hognose is well known for its feigning-death behavior when disturbed. The racer, Coluber constrictor, living throughout the region except for the Canadian provinces, is a common species of the open grasslands. The prairie rattlesnake, Crotalus viridis, is found throughout the region except for Manitoba. It is often associated with prairie dog towns and is much maligned because of its poisonous nature. The gopher snake, Pituophis catenifer, also occurs throughout except for Manitoba. This harmless snake of the open prairies can be more than six feet long and because of its hissing behavior gives the appearance of being dangerous. In fact, perhaps many of the reports of rattlesnake encounters may actually involve the gopher snake.

Even though amphibians and reptiles are frequently inconspicuous to the casual observer, they are a common and important component of the fauna of the Great Plains.

Royce E. Bollinger University of Nebraska-Lincoln

Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and Amphibians: Eastern and Central North America. Boston: Houghton Mifflin Company, 1991.

Lynch, John D. "Annotated Checklist of the Amphibians and Reptiles of Nebraska." Transactions of the Nebraska Academy of Sciences 13 (1985): 33–57.