Woodhouse's toad has a light midline on the back on a background of brown or gray. The warts are often in sets of two or more on each dark brown spot. The cranial ridges are in contact with the elongated parotoid glands and the underside is white except for a small dark gray spot well forward on the breast. This is especially prominent in specimens from eastern Iowa. The dark throat pouch of males of most toads covers most of the throat and is much larger than the breast spot.

   The best single feature to separate Woodhouse's toad from the American toad is the white underside of Bufo woodhousei, whereas American toads have the breast mottled with gray. Other distinctions are less reliable since American toads also usually have a weak mid-dorsal stripe and it is at times difficult to distinguish the spots bearing the warts. Bufo americanus and B. woodhousei occasionally hybridize producing intermediate individuals. Hybrids have been found in both southeastern and southwestern Iowa. Great plains toads have large olive-colored blotches
and are easy to distinguish from either of the other species.

   There are two subspecies of Bufo woodhousei in Iowa. Woodhouse's toad, Bufo woodhousei woodhousei, occurs in the western two tiers of counties north to Plymouth County and is large, more than 4 inches (103 mm) long. Fowler's toad, Bufo woodhouseifowleri, is found in southeastern Iowa north to Scott County and is much smaller. The largest specimen we have found is only 3 1/4 inches (81 mm) long.

The call of Bufo woodhousei is a sheeplike, flat "wa-a-a- a," an almost buzzing, non-melodious trill. It sounds a Iittle like the cry of a newborn child. This toad calls in May and June, later than most American toads. Woodhouse's toad is more adapted to arid conditions than American toads and is nearly limited in western Iowa to the loess hills and the adjacent Missouri River floodplain. Fowler's toad is found in more-or-less arid, sandy habitats in southeastern Iowa. Both subspecies are abundant wherever they occur in Iowa.

American toad (mottled breast on left) and Woodhouse's toad on right.