Western Toad (Bufo boreas) 



Description: Adults have dry skin with small warts, and are gray, brown, or olive-green with a 

 prominent white or yellowish line down the center of the back; very young transformed toads 

 typically lack the dorsal line, and the warts are often red-brown in color. The adult has a 

 snout-vent length of 6.5-12 cm. This is the only toad in northwestern Montana, and can be 

 distinguished from toads in other areas of Montana by: 1) a cranial crest faint or absent; 2) 

 oval parotoid glands; 3) two tubercles on the sole of the hind feet; and 3) a horizontal pupil. 

 Tadpoles are typically jet black, while all the Montana frog species tadpoles are green or 

 bronze. Eggs are laid in long, clear, double strings, and each has a black embryo. 



Habitat and Habits: Adult Western Toads are largely terrestrial and found in a variety of habitats 

 from valley bottoms to high elevations; they breed in lakes, ponds, and slow streams with a 

 preference for shallow areas with mud bottoms. Breeding and egg laying in northwestern 

 Montana usually takes place a month after snow-melt, from April at lower elevations to July 

 at higher sites; Black and Brunson (1971) reported mating activity and egg masses in mid- 

 May near Hamilton. In 1 995 adult mating behavior was noted at Kramis Pond (4290') near 

 Lake Como on 19 May. Small toads (2-2.5 cm snout-vent length) were found around shore, 

 but sweeping revealed no tadpoles; tadpoles 3 cm total length were found there on 16 June. 

 Egg masses with large embryos, and tadpoles up to 3.5 cm total length with 2 mm hind limbs, 

 were found near Victor (3450') on 16 June 1995. One small adult and many tadpoles were 

 found at Lost Trail Pass bog (7060') on 24 July 1995. Tadpoles typically take 2-3 months to 

 metamorphose in Montana, depending on water temperature (Black 1970b). At 

 metamorphosis, himdreds of small toads, many with the tails still present, can be foimd on the 

 shores of breeding ponds. 



Surveying: Tadpoles are seen in ponds during the day and can be sampled with a dipnet. During 

 the breeding season, adults may be seen in the water but otherwise they are found in more 

 terrestrial habitats. 



Status: During the 1995 survey. Western Toad reproduction was noted on or near all but the West 

 Fork District, but only at one site each. Western Toads were encountered at 16 sites in 1995 

 (Appendix 3), but the paucity of reproductive effort is of concern. Declines have recently 

 been recorded in Yellowstone National Park (Peterson et al. 1992), Wyoming, and Colorado 

 (Carey 1993). We recommend that a monitoring program be set up for this species, and 

 special efforts made to check more high-mountain lakes and ponds. 



Montana Natural Heritage Program rank: G4 S4. 



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