The American toad is the most common species of toad in North America. Though it is most often found in the eastern U.S., it also lives in parts of Canada and Mexico. This toad belongs to the Bufo Americanus genus, which has three subspecies in a variety of sizes and colors. Although warts are associated with toads, these usually have just a few. They are extremely adaptable and can be found in many different environments where they feed on several types of invertebrates.
The Dwarf American toad is small, just 2-1/2 inches (6 cm) in length, while the common Eastern American toad may be over 4 inches (10 cm) long. The other subspecies, the medium sized Hudson Bay toad, is a Canadian resident that is seldom seen. Although they differ slightly in size and appearance, the subspecies are otherwise very much alike.
Like frogs, American toads have thick bodies with short front legs which each have four webbed toes and longer back legs with five webbed toes. They have thick skin that is most often brown, but can be shades of red, gray, or dull green, and with yellow or white bellies. Their color alters with humidity, temperature, or the stress in the environment, and the males tend to be darker in color than the females.
The American toad usually does not live a long time. In fact, most die before reaching the young toadlet stage. Those that do manage to survive beyond a few years have the capacity to live as long as 10 years or more. They reach sexual maturity at two or three years.
These toads are nocturnal and live a solitary life except during mating season. At this time they will gather with other toads in still or slow moving bodies of water that have few or no fish. Females select a male for breeding by the territory they have chosen as well as the strength of their mating call, which is a long, drawn out trilling sound. The male American toad will try to mate with any female that approaches.
During mating, the male toad grasps the female around the abdomen and moves with her as she lays between 4000 and 8000 eggs in two rows of long jelly like tubes. The eggs are laid in Chlorogonium algae which the tadpoles feed on after hatching. These eggs hatch quickly in anywhere from a few days to two weeks. In six to ten weeks, the young tadpoles morph into toadlets. This usually occurs throughout the warm summer months.
While tadpoles eat algae, the mature American toads are carnivores. They extend their tongues to capture various prey, which may include snails, spiders, worms, beetles, and slugs. They may eat as many as 1000 of these insects each day. Their fondness for slugs makes them a gardener's best friend; many gardeners even create “toad abodes” from small overturned pots to entice these beneficial creatures to stick around.
Gardens are just one of the toads' habitats; they are frequently found at night hunting for food in wooded areas, fields, and yards. During the daytime, they take refuge from the sun under any object they can find. Among their favorite hiding places are under wood piles, rotten logs, and porches.
American toads are preyed upon by several types of snake, although the common garter snake is their biggest threat. Toads try to deter these snakes from eating them by covering their bodies with urine to make themselves less palatable. They also emit chemicals from their skin that are toxic to many animals. Some snakes, like the garter snake, are immune to the chemicals, however.