Anaxyrus woodhousii

This toad has a broad distribution. It reaches the southwest area of Oregon, and is found through Idaho, Montana, and South Dakota; into western Iowa and western Missouri; south through Kansas, Oklahoma and Texas, and just into northern Mexico; through New Mexico, Arizona and into southeastern Nevada and southeastern California.

This species is found throughout most of central and southwestern USA and portions of adjacent northern Mexico. It is absent from high mountains and the West Coast.

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species is found throughout most of the central and southwestern United States and portions of adjacent northern Mexico. It is absent from high mountains and the West Coast.

This species (Woodhouse's Toad) is large for a toad, with normally proportioned limbs and a blunt snout. Its paratoid glands are narrow, and spread apart by more than one (parotoid) length. Cranial crests run lengthwise from the front of the eyes to back edge of the eyes, then turn sharply towards the side of the toad and extend to the outside edges of the eyes. The warts are dark and small. Each wart has a red spot at its tip. The toad is olive green on its dorsal side, with dark splotches and a pale stripe down center of back. The underside is creamy and unmarked, while the throat is slightly darker in color.

Subspecies include Anaxyrus woodhousii australis (Southwestern Woodhouse's Toad), A. w. velatus (East Texas Toad) and A. w. woodhousii (Woodhouse's Toad or Rocky Mountain Toad).

The habitat of this toad overlaps the habitat of Anaxyrus americanus and Anaxyrus woodhousi fowleri. The eggs of A. woodhousi resemble those of A. fowleri, and adult A. woodhousi resemble adult A. americanus.

See another account at californiaherps.com.

Length: 13 cm

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

Comments: Woodhouse's toads inhabit grasslands, desert and semi-desert shrublands, river valleys and floodplains, and agricultural areas, usually in areas with deep friable soils. When inactive, they burrow underground or hide under rocks, plants, or other cover. These toads live on land except during the brief breeding season. Breeding occurs in marshes, rain pools, ponds, lakes, reservoirs, flooded areas, stream pools or backwaters, and other bodies of water with a shallow margin lacking a strong current, including both permanent and temporary pools, generally in sites with few if any fishes.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Migrates up to several hundred meters between breeding pools and adjacent nonbreeding terrestrial habitats.

Comments: Metamorphosed toads eat mainly various small terrestrial arthropods. Larvae eat suspended matter, organic debris, algae, and plant tissue.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Represented by many and/or large occurrences throughout most of the range.

>1,000,000 individuals

Comments: Total adult population size is unknown but surely greater than 1,000,000.

Comments: Inactive during cold months of fall, winter, and early spring. Mostly nocturnal but diurnal activity is not uncommon. Active in wet or dry weather.

Breeding occurs in spring or summer, generally after rains. Several dozen adults may aggregate for breeding. Breeding choruses may last a few weeks. Females deposit a clutch of up to 25,000 eggs in long strings. Larvae metamorphose into tiny toadlets within 1-2 months. Individuals become sexually mature usually in 2-3 years.

Year Assessed

Assessor/s

Reviewer/s

Justification

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Common and widespread; tolerant of various kinds of habitat disturbance; no evidence of significant regional or rangewide declines.

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Moderate to broad.

This species flourishes in any moist area, from irrigation ditches to canyons to swamps. It breeds from March to July and lays eggs in shallow, slow moving, ephemeral bodies of water. The tadpoles metamorphose in a single season.

Population

Population Trend

Global Short Term Trend: Relatively stable (=10% change)

Comments: The population trend varies with location but is probably stable in most areas. See Sullivan and Lamb (1988) for evidence that B. woodhousii is displacing B. microscaphus in central Arizona.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: In some areas this species has increased in area of occurrence and population size through human augmentation of breeding habitat.

Degree of Threat: Medium

Comments: Overall, not threatened. Locally threatened by human-caused habitat degradation and destruction and by mortality on roads near breeding sites.

Major Threats

Conservation Actions