Lithobates blairiPlains Leopard Frog

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Geographic Range

The plains leopard frog enjoys arid regions of the plains and prairies. It can be found along streams and ponds in western Indiana to southeast South Dakota and eastern Colorado. It can also be found south to central Texas and isolated colonies in southeast Illinois, New Mexico, and southeastern Arizona (Conant 1991).

Habitat

The plains leopard frog basks on vegetation mats at the edge of shallow streams and ponds. The frogs occur clumped in small groups during breeding season and during the fall, but may be widely dispersed when actively foraging. Lithobates blairi is active at warmer temperatures and has a critical thermal maximum body temperature of 37°C (BISON-M 1997).

Physical Description

The plains leopard frog is stocky and usually brown in color. It has a distinct light line along the upper jaw and a dark spot on the snout. The tympanum is equal or slightly larger than the eye, often with a light spot in the center. Dorsolateral folds are inset medially and interrupted just anterior to the groin. The groin and ventral surface of the thighs are considerably yellow in color. The area around the cloaca is covered with tubercles. Size: 2 - 3 3/4 inches (BISON-M 1997, Conant 1991).

Development

Reproduction

Breeding takes places anywhere from February-October. Most move from overwintering sites to breeding sites in the spring. Males engage in sexual displays on the ground. Breeding rates, although variable, seem to peak following rains. Eggs are deposited in still, temporary or permanent shallow ponds or pools. The eggs are light gray in color. In Oklahoma, most clutches found contained 4000-6500 eggs, but some with fewer than 200. Hatching occurs in 5 to 20 days and larvae transform about three months after eggs are deposited. When clutches are lain in late summer or early fall, larvae may overwinter and wait until the following spring to metamorphose. Tadpoles are tan and nondescript without distinct color patterns (BISON-M 1997).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Behavior

Call:

The call is distinguishable from Rana pipiens (Northern Leopard Frog) on the basis of call duration and pulse repetition rate. The mating call has a pulse rate of 3/sec and is usually described as 2 or 3 distinct "chucks" (Conant 1991).

Food Habits

The plains leopard frog feeds on a variety of insects. They mostly use the sit and wait strategy. Once prey items have been sighted, they will stalk and seize them. The plains leopard frog will also actively forage either terrestrially or at the waters edge. They often forage away from water at night after a summer rain (BISON-M 1997).

Conservation Status

Named an animal of special concern in Indiana

Other Comments

Lithobates blairi was previously believed to be a conspecific of the northern leopard frog. In 1973, the plains leopard frog was described as a separate species. Some previous names of L. blairi include Rana pipiens brachycephala, Rana pipiens pipiens, Rana pipiens berlandieri, and Rana halecina. The plains leopard frog's main predators are raccoons, skunks, opossums, and the western gartner snake. Also, with the introduction of the bullfrog (Rana catesbeiana) into Colorado, L. blairi numbers have decreased. The major threats on their population seem to be habitat destruction and predation by bullfrogs (BISON-M 1997).

Contributors

Trudy Kuhrt (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

References

BISON-, M. 1997. "(Biota Information System of New Mexico database)" (On-line). Accessed (Date Unknown) at www.fw.vt.edu/fishex/nmex_main/species/020040.htm.

Conant, R. 1991. Peterson Field Guides: Reptiles and Amphibians of Easter/Central North America. Boston: Houghton Mifflin Co..