Spotted Frog (Rana pretiosa) 



Description: Adults are dark to light brown, gray, or olive green with dark spots (frequently with 

 lighter centers) found on the back, sides and legs. The number and pattern of spotting is 

 quite variable. The back and sides are often covered with small bumps. The underside of the 

 legs is bright red, salmon, or orange; this bright color may extend up to the chin or be 

 replaced by a light, mottled gray on the chin, chest, and/or belly. In younger subadults, 

 bright leg color is often lacking and instead a light, lemon-colored wash is present. In these 

 subadults there is often a dark mask present, with a light jaw stripe extending to the shoulder; 

 both the mask and jaw stripe may be less obvious in larger, older animals. The adult has a 

 snout-vent length of 2-4". The bright colored pigment on the undersides of the legs of adults 

 distinguish this species from all other frogs in Montana. Younger individuals, without bright 

 legs, may be distinguished by a combination of: 1) dorsal spots usually present but not 

 surrounded by light-colored halos; 2) dorsolateral folds present; 3) toes without pads at the 

 tips; 4) light, lemon-colored wash on the undersides of the legs; and 5) pale gray, not white 

 belly. Eggs are laid in large, globular masses of 150-500 at the surface of the water. The 

 tadpoles are dark green on top with some gold flecking whereas the underside has an 

 iridescent bronze color. Total length of tadpoles may reach 3"; the eyes are located on top of 

 the head. 



Habitat and Habits: Spotted frogs are regularly found at the water's edge in forest habitats. 

 Wetlands in or near treeline, are also used, but populations are uncommon in the large, open, 

 inter-mountain valleys. The Spotted frog was commonly found on all districts of the KNF 

 from the valley floor at 2350 ft. to over 6180 ft elevations in the Cabinet, Three Rivers and 

 Fortine districts. Individuals were found in every type of wetland habitat although numbers 

 varied widely from 1-35 or more at a site. Breeding takes place in lakes, ponds (temporary 

 and permanent), springs, and occasionally backwaters or beaver ponds in streams. All the 

 egg masses in a particular pond are often found in the same location and at the margin of the 

 pond. Because of their location, the eggs are susceptible to drying up if pond levels recede 

 substantially before tadpoles hatch out. Such was the case in the summer of 1994 in the KNF 

 where extensive egg mortality was observed in at least five instances. Eggs were found as 

 early as 28 April 94 at a pond near Bull Lake and as late as 29 May 93 at Frog Lake; 

 however, since tadpoles were also present on 28 April 94, some eggs must have been laid as 

 early as 15 April 94. Tadpoles were seen from 28 April 94 through 12 August 94. Recently 

 transformed froglets were found in numbers along Freezout Creek on 1 Aug 93. Eggs hatch 

 in 2-3 weeks and tadpoles take 2-14 months to metamorphose, depending on water 

 temperature (Nussbaum et al. 1983, Turner 1958). Young and adult frogs often disperse into 

 marsh and forest habitats, but are not usually found far from open water. 



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

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



Status: The most common frog on the KNF and elsewhere in western Montana. The Spotted frog 

 in Montana is currently a U.S. Fish and Wildlife Service Category 2 Candidate species; 

 elsewhere in its range it is listed as a C-l, with Threatened/Endangered status warranted but 

 precluded by work on higher priority species (U.S. Fish and Wi vice 1 993). 



Significant declines are known from the southern end of the ri la. southern Idaho, 



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