General Adult Description: Overall, American Toads are similar in appearance with Canadian Toads. Both these toads have a background color that is various shades of tan or brown. The back is covered in small to medium sized dark spots that typically contain one or two large warts per spot. The underside is mottled with black spots. A narrow white or pale line runs down the middle of the back. Prominent cranial crests are visible between and posterior to the eyes and not fused between the eyes (no boss is present). Enlarged kidney-shaped parotoid glands are either not in contact with the cranial crests or are connected by a small spur that extends posteriorly. 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. This species can be easily identified from other South Dakota toads by: 1) having a mottled underside (Woodhouse’s Toads and Great Plains Toads have white undersides) and 2) the absence of a boss between the eyes (Canadian Toads have a boss present between the eyes).
General Larval Description: Larval American 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: Male American Toads have a melodic trill lasting from 5–30 seconds in length. The call of Canadian Toads is similar but often described as being less musical, harsher, and shorter in duration (3–6 seconds). Because this species may hybridize with Canadian Toads, hybrids may have call characteristics intermediate of both species.
Behavior: The American Toad is primarily nocturnal and is a generalist predator that consumes a variety of insects and small invertebrates. Near urban or developed areas toads will congregate under outdoor lights and catch insects that are attracted to the lights. Like most toads, American Toads have spades that allow them to be proficient at digging into the substrate to bury themselves. During winter, all toads bury themselves (or use existing rodent burrows) below the frost line to avoid freezing temperatures.
Reproduction: This species breeds from late May to June and typically arrives at wetlands after Boreal Chorus Frogs have arrived. Like most toads, eggs are laid in long strands and hatch shortly after being laid. This species is known to hybridize with Canadian Toads and hybrids can have characteristics intermediate to both species. Tadpoles will undergo metamorphosis 5–8 weeks after hatching. Juvenile toads will often remain along the margins of wetlands for several weeks after metamorphosing to feed before dispersing.
Habitat: American Toads can be found in most aquatic habitats in their range, but infrequently use ephemeral or temporary wetlands (unlike Great Plains Toads). Semi-permanent or permanent wetlands, lakes, and reservoirs are all common breeding habitat for this species. After breeding, most adults can be found in upland prairie habitats.
Species Range: This species can be found across New England, Appalachia, and Great Lakes Region, south into the northern portions of Mississippi, Alabama, and Georgia, west the eastern borders of North Dakota and Nebraska, and north into eastern and central Canada.
South Dakota Range: The American Toad can be found along the eastern border of South Dakota, but appears to be absent from much of southeast corner of South Dakota.
South Dakota Status: This species is not listed by South Dakota Game, Fish and Parks.
Account written by Drew R. Davis