Western Toad (Anaxyrus boreas)
Order Anura; Family Bufonidae; Genus Anaxyrus; Species boreas. Bufonidae represents 'true toads', characterized by parotoid glands and typically dry, warty skin.
Species
Western Toad (Anaxyrus boreas)
Family
Order Anura; Family Bufonidae; Genus Anaxyrus; Species boreas. Bufonidae represents 'true toads', characterized by parotoid glands and typically dry, warty skin.
Size
Adult SVL typically ranges from 5.6 to 13 cm (2.2 to 5 inches). Females are generally significantly larger than males. Metamorphs are tiny, often only 1 cm long.
Conservation
Listed as Near Threatened or Endangered in several specific southern and high-altitude regions (e.g., Colorado, New Mexico). Global status is Least Concern, but populations are declining due to Chytrid fungus (Bd), habitat fragmentation, and road mortality.
Description
The Western Toad is a quintessential 'garden toad' of the Pacific Northwest and Rockies. It is a slow-moving, stoic amphibian often found on trails or roads at night. Its pale racing stripe down its back makes it look as though it were painted for a miniature marathon.
Key Features
White/cream mid-dorsal stripe; absence of cranial crests (flat skin between eyes); large oval parotoid glands; 'walking' gait.
Physical Description
A large, robust toad with a blunt snout and short limbs. It features large, conspicuous oval parotoid glands situated behind the eyes, which are wider apart than the length of the glands themselves. The pupils are horizontal and the eyes possess a pale iris. Unlike many other toads, it lacks cranial crests (bony ridges on the head between the eyes).
Skin Texture & Coloration
The skin is dry and covered in numerous small, rounded warts (tubercles). Dorsal coloration ranges from dusky gray and brownish to olive-green. A prominent, thin cream-colored or white stripe runs down the center of the back (vertebral stripe). The underside is pale with dark, irregular mottling. Warts are often surrounded by black blotches or may be reddish in some individuals.
Distinguishing Features
The presence of a well-defined white or cream dorsal stripe and the total absence of cranial crests are the primary diagnostic features. The parotoid glands are widely separated and oval-shaped.
Habitat
Highly versatile; found in mountain meadows, forests, grasslands, and desert riparian areas. It requires permanent or semi-permanent water for breeding (ponds, slow streams, or lake margins) but is largely terrestrial as an adult.
Geographic Range
Western North America, ranging from southern Alaska and Yukon south through British Columbia, the western US (Washington, Oregon, California, Idaho, Nevada, Utah, Wyoming, Montana, Colorado), and into Baja California, Mexico.
Behavior
Primarily nocturnal, especially in warmer areas, but can be diurnal at higher elevations or in cooler weather. It tends to walk rather than hop and is an excellent burrower, often occupying the burrows of small mammals or digging its own.
Diet & Feeding
Generalist carnivore. Adults eat a wide variety of invertebrates including ants, beetles, spiders, moths, and worms. They use a 'sit-and-wait' ambush strategy, flicking out a sticky tongue to grab prey.
Reproduction
Breeds in spring or early summer depending on snowmelt/temperature. They practice axillary amplexus. Females lay up to 12,000 eggs in long, double-string gelatinous coils attached to underwater vegetation or resting on the bottom.
Vocalizations
Unlike most frogs, males do not have a vocal sac and do not produce a loud 'chorus'. They produce a faint, bird-like chirping sound, often described as the sound of a 'struggling rubber ducky', usually as a release call when touched by another male.
Life Cycle
Eggs hatch in 3–10 days. Tadpoles are dark (almost black) and aggregate in large, dense schools in shallow, warm water. Metamorphosis occurs in 2–3 months. They can live up to 10–12 years in the wild.
Conservation Status
Listed as Near Threatened or Endangered in several specific southern and high-altitude regions (e.g., Colorado, New Mexico). Global status is Least Concern, but populations are declining due to Chytrid fungus (Bd), habitat fragmentation, and road mortality.
Toxicity & Defense
Possesses parotoid glands that secrete bufotoxins when the toad is stressed or bitten. These whitesh, milky secretions are irritating to mucous membranes and can be toxic or lethal to small mammal predators or pets if ingested.
Ecological Role
Acts as both a significant predator of agricultural pests (beetles/grasshoppers) and a prey source for garter snakes, ravens, and raccoons. Its presence indicates high-quality terrestrial and aquatic connectivity.
Similar Species
Woodhouse's Toad (Anaxyrus woodhousii) has prominent L-shaped cranial crests. Yosemite Toad (Anaxyrus canorus) has smaller parotoid glands and more distinct sexual dimorphism in color.
Observation Tips
Look on paved paths or roads near water bodies shortly after sunset during warm, humid evenings. Their white dorsal stripe often reflects flashlight beams easily.
Handling & Safety
Handle with wet hands only if necessary. Wash hands thoroughly afterward to remove secretions, which can cause severe eye irritation. They are sensitive to chemicals on human skin (lotions, bug spray).
Seasonal Activity
Active from late March to October depending on elevation. They spend the winter in deep underground burrows (hibernation) to avoid freezing temperatures.
Cultural Significance
Historically featured in indigenous stories of the Pacific Northwest as a symbol of the earth or as a weather-bringer. In modern times, it is an indicator species for the health of alpine wetlands.
Interesting Facts
Tadpoles of this species are known for 'schooling' behavior, forming massive dark clouds in the water to confuse predators. They are one of the few amphibians that can tolerate the high-elevation conditions of the Rocky Mountains.