General Information
Boreal toad (Bufo boreas) is a large toad species, between 5.6 and 13 cm long, of western North America. It has a white or cream dorsal stripe, and is dusky gray or greenish dorsally with skin glands concentrated within the dark blotches. Its parotoid glands are oval, widely separated, and larger than the upper eyelids. It is mottled venter, has horizontal pupils, and lacks cranial crests.
Compared to females, males have smoother skin, reduced dorsal blotching, and nuptial pads (thickened skin) on their forefeet during breeding season. In juveniles of this species, the dorsal stripe is weak or absent. Large young have prominent dorsal and ventral spotting and yellow feet. The Western toad is a common species occupying a wide variety of habitats, but is listed as near threatened (largely due to the impact of chytridiomycosis). It is frequently encountered during the wet season on roads or near water at other times. When handled, adults often vocalize (sounds like a peeping chick) while struggling. It eats any type of insect it can catch. It also has an amazing jump.
Other Information
Boreal Toad Range Map, statewide scale
Management
The boreal toad was considered the most abundant amphibian of the western third of the state in previous decades (Rodgers and Jellison 1942, Brunson 1952, Maxell 2003), and is still encountered widely and frequently though by no means commonly, and is no longer ranked as the most abundant amphibian. Numerous surveys since the early 1990's indicate that this species has experienced regional population declines in the state. Boreal toads were documented to breed at only 2 to 5% of more than 2000 standing water bodies surveyed since 1997, and where breeding was documented, fewer than 10 breeding females contributed in a given year (Maxell 2000, Maxell et al. 2003). Thus, range-wide declines for this species in the western United States are also reflected in the Montana results. Because the reasons for declines in Montana remain obscure, it is difficult to suggest management techniques to reverse the trend. Nevertheless, the following should help reduce some immediate impacts. First, reduced access by livestock to known breeding sites within grazing allotments will prevent undue trampling mortality (Bartelt 1998). This can be accomplished by constructing partial or complete livestock exclosures (fencing) at breeding ponds and other sites. Second, use of fertilizers, herbicides, and pesticides within at least a 100 meters buffer zone of breeding sites should be avoided. Third, stocking predatory game fish at sites currently lacking them should be avoided, even though there is evidence that some species of trout do not prey on boreal toad tadpoles and eggs (Jones et al. 1999). And before efforts are enacted to remove undesirable fish by use of lethal chemicals, a survey for toads at the target water bodies should be conducted to prevent unnecessary mortality to any life stages. If toads are present, they can be removed by dipnet and held in captivity (under appropriate conditions) until the effects of the treatment dissipate, then returned to the site. Finally, known breeding sites should not be drained or altered, and water bodies where alteration is planned should first be surveyed for use by toads.