Utah). While significant declines are also apparent in coastal Washington, Oregon, and 

 California, recent (as yet unpublished) research indicates that those populations are actually a 

 different species. 

 Montana Natural Heritage Program rank: G4 S4. 



Leopard Frog (Rana pipiens) 



Description: Adults are brown or green with large, dark spots surrounded by light-colored halos 

 on the sides and back. The dorso-lateral folds are usually lighter in color that the surrounding 

 background. The under-side is typically white, but may be cream-colored or yellowish. The 

 adult has a snout-vent length of 2-5". Newly transformed froglets may lack spots. 

 Habitat and Habits: Leopard frogs are found in or near water in non-forest habitats. Typically 

 the vegetation is dense, e.g., a dense, sedge wet-meadow or cattail marsh. Breeding takes 

 place in lakes, ponds (temporary and permanent), springs, and occasionally backwaters or 

 beaver ponds in streams. Eggs are laid in 2-5" globular masses composed of hundreds to 

 thousands of eggs (Hammerson 1982a, Nussbaum et al. 1983). In Colorado, eggs hatch in 4- 

 15 days and tadpoles take 8-15 weeks to metamorphose, depending on water temperature 

 (Hammerson 1982a). 

 Surveying: Both tadpoles and adults are seen in and along the water during the day and can be 



sampled with a dipnet; adults may also be captured by hand- 

 Status: Historically, the Leopard frog was widespread in Montana but it now appears to have 

 been extirpated throughout much of the western part of the state. Re-surveys of 12 known 

 historical sites west of the Continental Divide during the past two summers have failed to 

 reveal a single individual. It is still common and wide-spread in the southeast corner of the 

 state, but its status is uncertain in central and northeast Montana. It appears that only 

 localized populations are present on the western edge of the plains. There are two historical 

 records within the KNF, one north of Rexford and one north of Noxon. Although it was 

 impossible to pinpoint the exact localities for these records, wetlands in the immediate area 

 were surveyed this past summer and Leopard frogs were not found. There are a number of 

 large open marsh areas at lower elevations, such as in the Lost Prairie-Pleasant Valley area or 

 along the Bull River and Clark Fork which appear to be ideal habitat and may have 

 contained, or currently do contain, Leopard frog populations. In many other areas in North 

 America where the Leopard frog was common a few decades ago, it is now gone. 

 Widespread extirpations are known from Alberta (Koonz 1993), Wyoming, Colorado 

 (Hammerson 1982b, Corn and Fogelman 1984), Idaho (Groves and Peterson 1992), 

 Washington, and Oregon (Leonard et al. 1993). Bullfrog and fish introductions, acid rain, 

 ozone depletion, immune system suppression, and "Postmetamorphic Death Syndrome" have 

 all been suggested as causes for frog extirpations in other areas (Corn and Fogelman 1984, 

 Hammerson 1982b, Carey 1993, Leonard et al. 1993). 

 Montana Natural Heritage Program rank: G4 S4. 



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