Great Plains Toad Anaxyrus cognatus

Family: Bufonidae

General Adult Description: Great Plains Toads is a large species of toad reaching average sizes of 3–4 inches (7.6–10.2 cm) in length. Toads have a background color that is typically light tan with 6–8 large dark green blotches often outlined in white. It has a white underside typically with a single black spot on the chest. A narrow, white or pale line runs down the middle of the back. Like most true toads, the Great Plains Toad has prominent cranial crests between which come together towards the nares to for a V-shape. Small, rounded parotoid glands are often in contact with the cranial crests posterior to the eyes. Adult males have nuptial pads (dark, keratinized pads) on the first and second digits of the forearms that are used to help grasp the female during amplexus (breeding); females lack these pads. It can be easily identified from other South Dakota toads by: 1) the presence of a white underside (American Toads and Canadian Toads have a heavily mottled underside) and 2) the presence of 6–8 large dark green blotches often outlined in white on its back (Woodhouse’s Toads have numerous, small black spots).

General Larval Description: Larval Great Plains Toads can be difficult to distinguish from tadpoles of other species of true toads (Bufonidae). Tadpoles are small, black, and may be covered in small metallic gold flecks. The tail fin is clear and rounded at the tip.

Call Description: The call is a long, extended, pulsating trill with a metallic quality often lasting from 10–50 seconds in duration.

Behavior: This species spends a considerable amount of time underground, usually only being active during a few favorable weeks in the spring, summer, and fall. When agitated, individuals will commonly inflate their lungs, increasing the size of their body. The Great Plains Toad is primarily nocturnal and is a generalist predator that consumes a variety of insects and small invertebrates.

Reproduction: This species is what is considered to be an explosive breeder. The breeding season can last from late May through July but is primarily determined by heavy rainfall events. During and shortly after heavy rain events adults emerge from burrows and proceed to ephemeral bodies of water to reproduce. Breeding activity is typically intense for one or two days, then adults leave ponds to return to terrestrial habitats. Tadpoles typically undergo metamorphosis within five weeks of hatching, often corresponding with when these ephemeral wetlands begin to dry up.

Habitat: Great Plains Toads are primarily found in prairie and open grasslands, but can also be found in agricultural landscapes. Unlike most other toads, Great Plains Toads will use highly ephemeral wetlands during reproduction such as flooded fields. Large, permanent ponds are not used by breeding adults.

Species Range: This species is found throughout much of the central United States, from southern Canada through the Great Plains and eastern Rocky Mountains, to Arizona and northern Mexico.

South Dakota Range: The Great Plains Toad can be found across most of South Dakota, but appear to be absent from high elevation sites in the Black Hills.

South Dakota Status: This species is not listed by South Dakota Game, Fish and Parks.

Account written by Drew R. Davis and Trevor G. Bertsch

Distribution Map
Distribution map of Great Plains Toad (Anaxyrus cognatus)

County level distribution of this species in South Dakota. Map generated from data collected from voucher specimens and photographic records. See About for additional information.

Photographs
Great Plains Toad (Anaxyrus cognatus)
Great Plains Toad (Anaxyrus cognatus)