I received an inquiry a few weeks ago concerning the abundance of toads near Kramer, ND in southern Bottineau County. It seems that the toad population was experiencing some sort of an irruption, with the toads seemingly everywhere, including area highways. These toads were quite small, and had a long extension (like a very long toe) on the hind leg. That is indicative of the plains spadefoot toad.
The plains spadefoot is roughly 1½-2 inches long and as the name implies, have an extended digging spur or “spade” on their back feet. Unlike most toads their skin is smooth, and they have vertical pupils like cats. Their color is variable from gray or brown to perhaps creamy color.
Plains spadefoots are known to be explosive breeders, responding to wet periods where they utilize shallow and temporary standing water. They can develop from egg to adult within a month.
The plains spadefoot has a scattered documentation in the state but may be found mainly in the western half of the state, and more so south and west of the Missouri River. They are considered to be uncommon to locally abundant, usually in association with grasslands on sandy or perhaps gravelly soil.
Four other species of toads may be observed in North Dakota, the largest of which is the Woodhouse’s toad which are about four inches long. They range mainly south and west of the Missouri River
There is also the Great Plains toad, 3-4 inches long, variable in color, which can be found across the state. The last two, the American and Canadian toads, are difficult identify because they hybridize. They are between 2-3 inches long. However, the Canadian toad is more widespread, particularly north and east of the Missouri River. The American toad has a rather limited distribution, documented only in Cass, Richland, and Pembina counties.
It is interesting to note that the Canadian toad has been associated with “freckled areas,” areas of land roughly 30-60 feet in diameter where the soil is slightly elevated, forming a “freckled signature” on aerial photographs in Minnesota and also in Rolette and perhaps Burke County. They appear to have formed from large numbers of the toads digging into the soils in large numbers to hibernate. Over 3,000 toads were found hibernating in a mound in Minnesota during the 1960’s.
~Chuck Lura
