Adult snout-vent lengths range from 47 to 103 mm for males and from 49 to 115 mm for females. The body is large and broad, with prominent parotoid glands, and numerous, small dorsal tubercles. On the head, the two cranial crest form a "V" between the eyes. Dorsal coloration is usually greenish, but may be grey, brown, or brownish-yellow. Large dorsal patches are paired and may be bordered by a black and a cream or white band. Smaller spots are present on the sides of the body, and green spots are found on the legs. Males have a black vocal sac, covered by a light-colored throat sac. The call is described as metallic and loud.

This species is known from the Great Plains and southwestern USA and northern Mexico. Southern Manitoba to southeastern Alberta, south to Aguascalientes and San Luis Potosí, Mexico; east to western Minnesota, western Iowa, central Missouri, central Oklahoma, and northern and western Texas; west to central Montana, eastern Wyoming, eastern and south-central Colorado, southeastern California, then north through southern Nevada and Arizona to northern Utah and south to Sonora and northerns and central Sinaloa (see map in Krupa, 1990). It is commonly found up to 1,800m asl, and up to 2,440m asl in Colorado.

The range of Great Plains toads stretches from extreme southwest Manitoba, Canada, to southeast Alberta, Canada, and south to Texas; eastern-central Utah to extreme southeast California and far south into Chihuahua, Coahuila, Durango, and San Luis Potosi, Mexico. There is a disjunct colony of Great Plains toads in south-central Colorado.

Biogeographic Regions: nearctic (Native )

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

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

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)) Range encompasses the Great Plains, southwestern United States, and northern Mexico, from southern Manitoba and southeastern Alberta in Canada, south to Aguascalientes and San Luis Potosi, Mexico; east to western Minnesota, western Iowa, central Missouri, central Oklahoma, and northern and western Texas; west to central Montana, eastern Wyoming, eastern and south-central Colorado, southeastern California. In the western segment of the distribution, the range extends north through southern Nevada and Arizona to northern Utah and south to Sonora and northern Sinaloa. Distribution in the desert part of the range is highly fragmented (Stebbins 2003). Elevational range is mostly between sea level and 6,000 feet (1,800 meters) but extends to 8,000 feet (2,440 meters) in Colorado (Hammerson 1999).

The range extends westward from central Missouri, western Minnesota, and Iowa into central Montana, southeastern California, and Nevada. It extends southward from southern Manitoba to Alberta into Aquascalientes and San Luis Potosi in Mexico. B. cognatus is usually found at elevations as high as 1800m, and as high as 2400m in the San Luis Valley of Colorado.
The habitat of B. cognatus includes both short and tall-grass prairie grasslands as well as mesquite grassland, desert scrub, an desert riparian associations in the western and southern portions of its range.

The adult Great Plains toad averages 4.8-9 cm in length. On its back it has large dark blotches. Each blotch is boldly bordered by light pigment and contains many warts. The colors of this toad are generally yellowish, brown, greenish, or gray on top. Below is unspotted, cream to white, with a yellow or orange-yellow seat patch. Some specimens have been found with a narrow, light mid dorsal stripe. The head of the Great Plains toad is relatively small with a well-developed cranial crest. Their snout is blunt and rounded.

Length: 11 cm

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

Great Plains toads are common toads of the great open spaces of broad grasslands, and the arid southwest. They are usually found in the lower, damper sections of these areas. These toads frequent irrigation canals, flood plains of rivers, temporary rain pools, and reservoirs.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: desert or dune ; savanna or grassland

Aquatic Biomes: rivers and streams; temporary pools

Other Habitat Features: agricultural ; riparian

Comments: Great Plains toads inhabit deserts, grasslands, semidesert shrublands, open floodplains, and agricultural areas, typically in stream valleys. When not active on the surface they usually occupy underground burrows. Breeding sites include rain pools, flooded areas, and ponds and reservoirs that fluctuate in size. Eggs and larvae develop in shallow water (usually clear). Calling males sit along the shoreline or brace themselves on submerged plants.

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 nonbreeding terrestrial habitats.

The Great Plains toad is an insectivore with a diet that includes, moths, flies, cutworms and beetles. Of its prey, cutworms pose the biggest problem to humans. This toad is known to be important to agriculture because they eat cutworms and many other noxious insects that feed on and damage crops. The Great Plains toad is nocturnal, thus feeds at night, which makes it hard to observe their food habits.

Comments: Metamorphosed toads eat primarily 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. Ranked S5 in AZ, CO, KS, NE, NM, OK, SD, TX, and UT.

100,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but likely exceeds 100,000.

Postmetamorphic young may form aggregations (J. Herpetol. 27:315-319).

Comments: These toads are inactive during cold winter months and during summer dry spells. Most activity is nocturnal, but these toads may active in daytime during wet or humid weather or when breeding.

Average lifespan

Status: captivity: 10.7 years.

Maximum longevity: 10.7 years (captivity) Observations: Longevity may be considerably underestimated.

The Great Plains toad breeds only after rain storms in spring and summer when the temperature exceeds 12 degrees C. Breeding sites are restricted to relatively clear shallow water, which include buffalo wallows, flooded fields, and the edges of extensive temporary pools. They breed usually in large congresses built up by the reaction of males to one another's call. A calling male clutches any toad that happens to touch him, and once a female is clasped she is retained tenaciously. A single female may lay as many as 20,000 eggs, which are attached to debris near the bottom of temporary pools, permanent springs, and small streams. Roughly two days after laying the eggs hatch. The tadpoles are small when first hatched and grow only to about 25 mm in length. About 1 1/2 months after the eggs are laid, metamorphosis begins and takes less than two weeks to complete. The newly transformed young of the year will not become sexually mature until they are 3-5 years old.

Range number of offspring: 20000 (high) .

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous

Average age at sexual or reproductive maturity (male)

Sex: male: 1460 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 1460 days.

Breeding occurs after warm rains in spring or summer. Male breeding choruses in a particular site usually last at least a few days but are of variable duration (up to two weeks or more) (Krupa 1994). Females toads are more likely to mate with males that call frequently. However, some males may sit quietly near calling males and sometimes intercept and successfully mate with females approaching the calling male. Individual females deposit clutches of several thousand eggs in shallow water. Larvae hatch in a few days and metamorphose in 2.5-7 weeks. Breeding pools do not hold water long enough for larvae to reach metamorphosis (Krupa 1994). Individuals become sexually mature in 2-5 years. In Oklahoma, this toad commonly exhibited communal egg deposition (Krupa 1994).

In order to protect this species its natural habitat must be protected. In many states in the Great Plains region there are laws in place that protect the plains. To ensure the continued survival of this species this protection of habitat must continue.

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Common and widespread in western and central North America; no major threats.

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Moderate to broad.

Other Considerations: Given the rapid declines in other anuran species, any indication of declines in this species should raise the GRANK to G4.

Population

Population Trend

Global Short Term Trend: Relatively stable to decline of 30%

Comments: Population trend is unknown but probably stable to slightly declining.

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

Comments: Likely relatively stable in extent of occurrence, probably less than 25% decline in population size, area of occurrence, and number/condition of occurrences.

Major Threats

Degree of Threat: C?

Comments: The Great Plains Toad uses some cultivated areas successfully. However, intensive cultivation and herbicide/pesticide use has probably led to reduced populations in some regions. Breeding sites are typically the result of heavy rains and hence not generally subject to loss via water projects. However, suburban sprawl has eliminated breeding and nonbreeding habitats in areas adjacent to growing cities in Colorado (Hammerson 1999), and some adults at these sites experience road mortality. Across the breeding range, populations appear to be localized.

Conservation Actions

Global Protection: Few to several (1-12) occurrences appropriately protected and managed

Comments: Unknown.

Needs: Unknown.

The Great Plains toad is an effective enemy of over-wintering cutworms in Oklahoma. Their value to agriculture on a yearly basis in Oklahoma has been estimated at $25 per individual toad.