The boreal toad (Anaxyrus boreas boreas) is the nominate subspecies of the western toad (Anaxyrus boreas). They are commonly found in the Southern Rocky Mountains, and their population has recently 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 other western toad subspecies, the California 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 Northern New Mexico, Colorado, Utah, Idaho, Wyoming, Montana, Washington, Oregon, British Columbia, Alberta, and Southeast Alaska. It prefers high-altitude wet habitats (8,000–12,000 ft in elevation) 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 Being omnivorous, boreal toads feed on a wide variety of insects and invertebrates as well as aquatic and non-aquatic plants. Their diet includes grasshoppers, beetles, flies, detritus, algae, 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. Survival of tadpoles to metamorphosis has been shown to be higher in aquatic environments with high trout presence, low chytrid fungus presence, and in non-permanent spawning pools. Trout presence decreases predation by aquatic insects, lower chytrid fungus concentrations help tadpoles through their highest vulnerability life-stage, and ephemeral spawning pools are warmer, leading to faster and larger tadpole growth. Chytrid fungus The chytrid fungus (Batrachochytrium dendrobatidis) causes a skin disease in many species of amphibian. It is spread mainly via contact with an aquatic habitat that is high in chytrid fungus load or with exposure to an infected individual, but it affects amphibians'