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AmphibianTerrestrialIntermediate
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Western toad
Anaxyrus boreas
A robust and adaptable terrestrial toad widespread in Western North America, known for its burrowing habits and preference for cool conditions.
Class:Amphibia
Order:Anura
Family:Bufonidae
Genus:Anaxyrus
Species:Anaxyrus boreas
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Environment
Terrestrial
Humidity
50 - 70 %
Day temperature
18 - 22 °C
Night temperature
14 - 16 °C
Ambient temperature
18 - 22 °C
Brumation temperature
4 - 8 °C
Minimum enclosure
>= 45 L
UVB
Medium
Species description
Geographical Origin and Habitat: Anaxyrus boreas is an anuran amphibian native to the western regions of North America. Its vast geographic range extends from southern Alaska and British Columbia, through the states of Washington, Oregon, Idaho, Montana, Wyoming, Nevada, down to northern California and the northern part of Baja California in Mexico, reaching as far east as Colorado. It inhabits a remarkable variety of environments, including mountain meadows, damp forests, river valleys, wetlands, and even desert areas near permanent or seasonal water sources, at altitudes ranging from sea level to over 3600 meters.
Taxonomy and Genetics: Belonging to the family Bufonidae, genus Anaxyrus (formerly classified under the genus Bufo, as Bufo boreas). Two subspecies are generally recognized: the nominate Anaxyrus boreas boreas (boreal toad) and Anaxyrus boreas halophilus (California toad). Genetically, populations display high variability due to geographic fragmentation, a factor that has prompted detailed phylogenetic studies to assess the conservation status of isolated mountain populations.
Behavior and Habits: This is a predominantly terrestrial and fossorial species. During the summer months or in warm areas, it is strictly nocturnal, spending the day inside burrows dug by itself or small mammals, or under damp logs and rocks. In cooler mountain areas or during spring, it is also active during the day. In winter, it enters a long period of underground hibernation in burrows below the frost line. It lacks an external vocal sac, so it does not produce a loud call, but emits a soft chirping sound when handled.
Morphology: It displays the robust, warty body typical of toads. Adults generally measure between 5 and 12 centimeters in length, with females being significantly larger than males. Dorsal coloration ranges from gray to brown or olive-green, with a characteristic light-colored vertebral stripe running down the back. Warts are often surrounded by dark blotches and can show reddish or yellowish tints. The parotoid glands behind the eyes are large, oval, and well-spaced, secreting a milky defense toxin.
Care, breeding and tankmates
Terrarium Setup: Requires a spacious, horizontally oriented terrarium. The minimum dimensions for a pair of adults are 80x45x40 cm. The essential element is a substrate at least 10-15 cm deep to allow burrowing; a mixture of organic topsoil, coconut fiber, and chemical-free soil is recommended, covered with leaf litter and cork bark. Include multiple dry and damp hiding spots. A shallow, wide water bowl is necessary for soaking, but water depth should not exceed the toad's shoulder height to prevent drowning.
Lighting and Heating: Lighting should follow a 12-hour photoperiod. The use of a low-intensity UVB bulb (2-5%) is highly recommended to prevent metabolic bone disease. This species requires cool temperatures: daytime ambient temperature must be kept between 18°C and 22°C (64-72°F), with a dry basking zone not exceeding 25°C (77°F). At night, the temperature should drop to 14-16°C (57-61°F). Avoid using high-wattage heat sources, as they do not tolerate extreme heat.
Humidity and Hydration: Ambient humidity should be kept moderate, between 50% and 65%, with spikes of 70-80% inside a damp hide filled with moist sphagnum moss. Light misting once a day is recommended. Water in the bowl must be changed daily, as toads often defecate in it; use only chlorine-free, conditioned water.
Feeding and Supplementation: A voracious species that will accept almost any moving prey. The diet should include crickets, roaches, earthworms, mealworms, and superworms. Adult toads should be fed two or three times a week, while juveniles can be fed every other day. It is essential to dust prey items with a calcium and vitamin D3 supplement once a week to prevent metabolic disorders.
Compatibility: A solitary species that tolerates the presence of similar-sized conspecifics, but must not be housed with smaller species that would be swallowed. Avoid cohabitation with tropical amphibians requiring warm, humid climates, or with reptiles that could injure them.
Health and Common Diseases: The main risks are metabolic bone disease due to calcium/UVB deficiency, intestinal impaction from swallowing large substrate particles (which is why fine or soft soil is recommended), and bacterial skin infections like red leg disease caused by poor hygiene. They are also susceptible to chytridiomycosis. New specimens must undergo quarantine.
Geographic Origin and Distribution
Anaxyrus boreas is an anuran amphibian native to the western regions of North America. Its vast geographic range extends from southern Alaska and British Columbia, through the states of Washington, Oregon, Idaho, Montana, Wyoming, Nevada, down to northern California and the northern part of Baja California in Mexico, reaching as far east as Colorado. It inhabits a remarkable variety of environments, including mountain meadows, damp forests, river valleys, wetlands, and even desert areas near permanent or seasonal water sources, at altitudes ranging from sea level to over 3600 meters.
Origin
Central America and CaribbeanNorth America
Amphibian profile
- Diet
- No verified data available
- Life expectancy
- No verified data available
- Adult size
- 12.5 cm
- Lifestyle/Microhabitat
- No verified data available
- Activity cycle
- No verified data available
- Sociality
- No verified data available
- Reproduction
- No verified data available
- Toxicity
- No verified data available
- Life stage
- No verified data available
- Handling tolerance
- No verified data available
- Brumation
- No verified data available
- Molting
- No verified data available
The catalog's scalar value is 12.5 cm. The AmphiBIO v1 source reports a maximum adult measurement of 12.5 cm for this species, recorded as snout–vent length (SVL). These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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