Toads

Description

Like frogs, toads are amphibians. They differ from most frogs because they have dry skin, warts, crests behind the eyes, and parotoid glands. The parotoid glands produce a poisonous secretion that helps the toad defend itself from predators. This substance, called a bufotoxin, can cause death in small animals and allergic reactions in humans. Toads have other ways to avoid being eaten too. If they’re brown or green in color, they can blend into their surroundings and escape detection. If brightly colored, they warn predators to stay away because they’re poisonous. Toads also puff up their bodies in an attempt to look bigger and inedible if a predator is nearby.

The smallest North American toad is the oak toad (Bufo quercicus), which reaches a length of only 1.3 inches (3.3 centimeters). Cane toads (Rhinella marina) are the largest toads and grow up to 9 inches (23 centimeters) in length. But a massive cane toad caught in Australia, nicknamed “Toadzilla,” has been described as the size of a small dog!

Range

Many toad species live throughout the United States. Toads are found on every continent, excluding Antarctica. Adult toads generally prefer moist, open habitats like fields and grasslands. The American toad (Anaxyrus americanus) is a common garden species that eats harmful insects and can be seen in backyards in the Northeast. Predators of toads include snakes, raccoons, and birds of prey.

Diet

Like frogs, most toads eat insects and other arthropods. However, some species eat reptiles, small mammals, and even other amphibians.

Life History

Each species of toad has a unique call. Males use their call to attract females for mating or to keep other males away from their territory. After toad eggs are fertilized, most hatch into tadpoles before becoming fully grown adults. Instead of legs, tadpoles have tails for swimming and gills to breathe underwater. As time passes, the tail becomes smaller and smaller until it eventually disappears. At the same time, the tadpole grows legs and loses its gills. Once this metamorphosis stage is complete, the adult toad is ready to live a terrestrial lifestyle. Not all toads (or frogs) have a tadpole stage. However, all amphibians require an unpolluted source of water to reproduce. The common toad (Bufo bufo) lives up to 40 years, but most toad species live about 5 to 10 years.

Conservation

Several toad species are federally listed as endangered or threatened. The biggest threats to toads are habitat degradation and invasive species.

Fun Fact

Touching a toad will not cause warts—however, the bufotoxin found on its skin can cause irritation.

Sources

BBC Nature

Cleveland Museum of Natural History

Encyclopedia Britannica

MSNBC

Northern Prairie Wildlife Research Center, United States Geological Survey

Ohio History Central

San Diego Zoo

U.S. Fish & Wildlife Service