General Adult Description: The Plains Leopard Frog is similar in appearance to the Northern Leopard Frog (Rana pipiens). Adults often measure from between 2–3.5 inches (5–9 cm) in length. Adult Plains Leopard Frogs have a background color that is usually tan with numerous conspicuous large dark blotches. A prominent white dorsolateral fold runs from the eye down to the hind legs and is “broken” near the posterior end. Where the line is broken, it is then inset medially (more towards the midline of the individual) and continues a bit farther. The ventral coloration is solid white. There is a large tympanum posterior to the eye that usually has a white spot in the middle. Adult males have an enlarged first digit on their forelimbs that is used to help grasp females during amplexus (breeding). Plains Leopard Frogs can easily be differentiated from Northern Leopard Frogs by the presence of broken dorsolateral folds (the Northern Leopard Frog has unbroken dorsolateral folds).
General Larval Description: Tadpoles are usually greenish to brownish in coloration with few, faint dark markings. These tadpoles are robust in size, reaching lengths of 1.5–2 inches (3.8–5 cm). The intestinal coil is visible through the venter. Tadpoles of this species are difficult to discern from Northern Leopard Frog tadpoles, but can be easily differentiated from American Bullfrog tadpoles that have a mottled venter and are covered in small black marks.
Call Description: Male Plains Leopard Frogs have a call that consists of two to four throaty, clucking notes repeated several times in rapid succession. Each cluck in this series rises slightly in pitch and ends in an accent. This call lacks the long, rattling snore that is part of the call of the Northern Leopard Frog.
Behavior: Adults are primarily nocturnal and will consume a wide variety of invertebrates. During the day, individuals are often found along the shore in vegetation. When startled, individuals will jump into the water and often remain submerged for several minutes. During winter months, adults and juveniles bury into mud at the bottoms of deep aquatic habitats to avoid freezing.
Reproduction: Plains Leopard frogs primarily breed in June in South Dakota, but reproduction has been observed as late as September (Davis et al. 2016. Herpetol. Rev. 47:648). Females lay eggs in large clumps often attached to vegetation. Tadpoles typically undergo metamorphosis in late July and August. In some cooler habitats, metamorphosis may not occur until the spring of their second year.
Habitat: Plains Leopard Frogs can be found in most aquatic habitats that occur in their range, including dugout ponds and backwaters of large rivers. Individuals are primarily found at these aquatic sites, but during wet, humid nights individuals can disperse into upland habitats. While mostly a grassland species, it can also be found in riparian forests and other deciduous forests within their range.
Species Range: Plains Leopard Frogs are distributed throughout much of the Great Plains and into the central Midwest. They occur from southeast South Dakota east through Iowa and Illinois to Indiana and south into Texas and New Mexico.
South Dakota Range: The Plains Leopard Frog is restricted to the southeastern and south-central regions of the state, often along the Missouri River and associated drainages.
South Dakota Status: This species is monitored by the South Dakota Natural Heritage Program. Any sightings of this species should be reported to South Dakota Game, Fish and Parks (report observation).
Account written by Drew R. Davis and Danielle E. Granberg