Plains Leopard Frog

Dorsal coloration is buff, pale brown, sometimes reddish-brown or olive green, with round dark brown spots often outlined by light narrow borders. Dorsolateral folds are usually interrupted posteriorly and displaced medially. Usually there is a complete pale supralabial stripe and a dark snout spot present. There is nearly always a white spot in the center of the tympanum. The posterior surface of the thigh has dark brown mottling or reticulations. The ventral surface is cream colored with some yellow on the groin and proximal portion of the thigh.

Found primarily in the Great Plains and Prairie Peninsula, ranging from southeast South Dakota to central Texas, and from southwestern Arizona to central Indiana. Original habitat for Rana blairi was probably prairie grassland, but it is now commonly found in areas of human disturbance.

R. blairi has been observed to use a wide variety of sites for breeding, including roadside and drainage ditches, marshes, rain pools, farm ponds, livestock tanks, streams, rivers and irrigation sloughs. Males frequently call from a floating position at the surface of the water. Breeding occurs some time between February and October, depending on local conditions. Eggs laid in late summer or fall may overwinter and transform the next spring. This frog has been observed to seek shelter in vegetation when disturbed, rather than in the water. Their tadpoles are preyed upon more readily than bullfrog tadpoles by several fish species. Adults are preyed upon by several species of snakes.

Suggested causes of the decline of some populations include water pollution, predation by introduced game fish, groundwater pumping, introduction of exotic fish and amphibians, agricultural development, increased aridity, habitat loss or alteration, competition with R. berlandieri, and predation, competition and/or larval inhibition by R. catesbeiana.

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).

Named an animal of special concern in Indiana

IUCN Red List of Threatened Species: least concern

Development - Life Cycle: metamorphosis

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).

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).

Biogeographic Regions: nearctic (Native )

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).

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).

Other Physical Features: ectothermic ; bilateral symmetry

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)

The Plains leopard frog (Lithobates blairi) is a spotted frog found in North America. It is sometimes referred to as Blair's leopard frog, named after the noted zoologist and University of Texas professor, Dr. W. Frank Blair.