The boreal toad is a subspecies of the western toad. They are commonly found in the Southern Rocky Mountains and in recent, their population has been on the decline due to an emerging amphibian disease, chytrid fungus. The boreal toad is currently listed as an endangered species by Colorado and New Mexico. It is known in Colorado as the only alpine species of toad.
Appearance
Boreal toads lack a cranial crest and can be distinguished from the Western toad by looking at its underbelly, which is covered by a considerable amount of dark blotches. Adult males on average are between 2.4–3.1 inches and females are 2.9–3.9 inches Their coloration can range from brown to green and they have a distinct white middorsal stripe. Both sexes have dry, warty skin and oval parotoid glands. Male boreal toads have no vocal sac, and therefore have no mating call.
Habitat and distribution
The boreal toad is currently found in Wyoming, Colorado, Idaho, Washington, British Columbia, Alaska, Utah and northern New Mexico. It prefers high-altitude wet habitats such as lakes, marshes, ponds, bogs and quiet shallow water Habitat selection for western toads is important because they require open water for breeding, and they can die if they are too exposed to seawater.
Diet
Boreal toads feed on a wide variety of insects and invertebrates. Their diet includes grasshoppers, beetles, flies, and mosquitos.
Reproduction
The breeding season is usually from May to Late July and occurs in marshes and still waters. Females on average lay about 3,000 to 8,000 eggs. The tadpoles take around two months to develop and are usually black in color.
Threats
The chytrid fungus causes a skin disease in many species of amphibian. Little is known to how it spreads, but it affects amphibians' by feeding off of the keratin produced by the amphibian, which causes keratosis. Keratosis then can either suffocate the amphibian, or cause it to go into cardiac arrest. This can be detrimental to amphibians because it inhibits their ability to absorb water and electrolytes.
