American Toad
Bufo americanus

by Jeff LeClere

See more info and photos: American Toad on the Iowa Herpnet site

Status

No status assigned in Minnesota.

Description

This is one of Minnesota's best known herp species. Adults are 2 to 3 1/2 inches snout to vent. The ground color is highly variable, but it is usually a shade of brown. Rarely it is gray, red, or greenish. There are black spots on the back. These spots contain one or two warts. These black spots often have a white border. They have an oval partoid gland behind each eye. The belly is white or yellowish and is heavily mottled with black. There is usually a light mid dorsal stripe down the back.

Subspecies

The subspecies found in Minnesota is the eastern American toad, Bufo americanus americanus.

Range

The American toad is found statewide in Minnesota.

Habitat

This toad is found everywhere in the state in every habitat. They are found in cities and towns, in parks and backyards. They only require semi permanent water for reproduction. Some wandering nonreproductive adults may be found in areas far from water.

Habits

These toads are diurnal for only a short period during spring and fall, but are mostly active at night in hot, humid weather. They may be seen catching insects under street or porch lights. I have, however, found them active (rarely) on hot days. To escape hot dry periods, they often burrow beneath the ground. Conversely, during rainy weather, they are very active above ground, especially at night when numbers of toads may be seen on the roadways.

They breed in the spring right around May 1. The males produce a high pitched trill that may last 30 seconds. The sound is similar to a whistle blown while underwater. At the breeding ponds, males may attempt to breed with anything that comes near them, including other male toads, or other species of frogs. Male toads and frogs make a release call when they are amplexed by other anurans. The female releases 20,000 eggs in a string that are fertilized externally by the male as they emerge. These hatch into little black tadpoles with gold speckles. They morph into toadlets in July when hundreds of tiny toads may be seen hopping around the shore. Adults and young burrow into the ground to avoid freezing temperatures in the winter.

Toads have many defenses against predation, but causing warts is not one of them! Toads do not cause warts. But they do produce a toxin in the partoid glands behind the eyes, It is only harmful if it is ingested or rubbed into the eyes. This toxin can make animals very sick. Some animals, such as garter snakes (Thamnophis sp.), are not harmed by this poison, so instead the toad puffs itself up with air to look bigger and to prevent the snake from swallowing it. It also urinates, but this really doesn't do any harm, it just makes it unappetizing to the predator.

Food

Toads eat anything small that they can fit into their mouths, which are mostly insects and various other invertebrates. Toads actually snap food up with their tongues instead of pouncing on their prey with their mouths open like many types of frogs do. Toads may use their hands and forearms to push large food items into their mouths. They are very valuable as controllers of insect pests.