Wildlife and the Outdoors
By Roger Clay, Wildlife Biologist
Perhaps when you were young, your mother or a grandparent told you not to pick up the toad you spotted in the back yard since handling the toad would give you warts. Of course, this was far from the truth but most likely caused you to leave the animal alone. However, if you were ever told not to eat a toad, this was better advice because four toads of the genus Bufo found in Alabama actually produce a toxin from glands seen as bumps or “warts” on their bodies.
Toads and frogs are amphibians. While there is no scientific distinction between the terms “toad” and “frog,” the word “toad” generally refers to a frog that has relatively dry, bumpy skin. In addition to the bumpy skin, toads hop when moving but a frog leaps.
The four Bufo toads in Alabama include Fowler’s toad, found statewide; American toad in the northeast; southern toad in the southern and western portions of the state; and the oak toad, found mostly in the southern portions of the state. All these toads are generally brown or grayish in color with darker spots. The oak toad, the smallest of these toads, has a light stripe down its back. Since the coloration can vary, it is not reliable to use the overall color of the toad as a key to identification. The best identification traits are the ridges and knobs found between and behind the eyes.
The musical trills of three of these toads vary in pitch and speed but are familiar nighttime sounds across Alabama heard on warm evenings near water when toads are breeding. The oak toad’s call is quite different, as it sounds similar to the “peep” of a chick.
Bufotoxin is the toxic substance secreted by the large parotoid glands located behind the eyes of the toads and is produced from the smaller bumps or warts on the toad’s skin. The toxin serves as a chemical defense for the toad. Any animal attempting to eat the toad would experience a very unpleasant event as the toxin reacts with mucous lining of the mouth and tongue. As an added defense, toads will inflate their bodies to become larger and harder to grab or swallow. While not harmful to touch or handle a toad, you do want to be careful and not rub your eyes afterward. It is always a good practice to wash your hands after handling a toad.
Chemical defense is not uncommon in the animal kingdom. Many insects employ this strategy as do some mammals--the skunk, for example. The brightly colored poison dart frogs of Central and South America are famous for their deadly skin secretions, which the frog actually obtains from certain ants it eats in the wild. In captivity, the frogs, deprived of their natural diet, will lose their toxic characteristics.
In Alabama, one animal eats toads with no detrimental effects. The hognose snake, known as “puff adder” or “spreading adder” by many, is immune to the effects of the toad’s toxin and toads are the favored food item of the snake.
The harmless toads hopping around your garden have been falsely accused of giving people warts. Harmless to hold, but you certainly do not want to kiss one. The experience may be most unpleasant and besides, the toad will not turn into a prince.
For more information contact Roger Clay, Wildlife and Freshwater Fisheries Division, 30571 Five Rivers Boulevard, Spanish Fort, AL 36527.
The Alabama Department of Conservation and Natural Resources promotes wise stewardship, management and enjoyment of Alabama’s natural resources through five divisions: Marine Police, Marine Resources, State Lands, State Parks, and Wildlife and Freshwater Fisheries.