Listed as a species of Special Concern, and a Species in Greatest Conservation Need.
This is Minnesota's largest toad species reaching 3 1/2 inches in body length. Adults are white, gray, or yellowish with several large oblong spots on the back. These spots, often paired, are gray, brownish, or greenish in color and contain many small warts. Some specimens have a white mid dorsal stripe down the back. The underside is plain white or light colored with no markings. The cranial crests are far apart and touch the roundish parotoid glands at the back of the head. In the front, they converge to form a boss, or a "bump" on the snout.
There are no subspecies of Anaxyrus cognatus recognized. This species was formerly placed in the genus Bufo.
The Great Plains toad is found only in western Minnesota. Records are documented from every county on the western border, and quite a few on the second or third county to the east. However, some of these have not been updated in the last 40 years in Minnesota. I have heard that some areas where they have been found before now lack specimens. Even so, they probably occur in most these counties; they just need to be updated. I updated records in Swift County in 1997 and Grant County in 1999. Pollution of breeding ponds is a factor in limiting their numbers.
Great Plains toads are found in open grasslands, prairies, and cultivated fields. They need water in which to breed in the form of temporary or (rarely) permanent water. Large shallow wetlands to flooded farm fields and irrigation ditches are used. Most breeding sites in Minnesota consist of flooded agricultural fields.
These toads are mostly active at night, especially in hot, humid weather. They spend most of their time underground in burrows they dig themselves with a tough spade-like projection on their hind feet. Spring and summer rains induce the toads to breed, typically June. They migrate to the breeding site (usually a flooded farm field) and the males begin to call. The call is like an American toads', but it is more mechanical and riveting sounding. The inflated vocal sack is sausage shaped and extends upward past the snout. Females lay strings of thousands of eggs which the male fertilizes externally. Tadpoles transform in 1 1/2 to 2 months. They may emerge from their burrows at other times of the year such as at night during periods of high humidity or during heavy thunderstorms, again mostly after sunset.
They eat any small insects or earthworms and even feed on harmful invertebrates in agricultural areas.