What is a Bullfrog?

A bullfrog is a native North American amphibian with the species name Rana catesbeiana. The species family is Ranidae, or “true frogs”. Swamps, ponds, and lakes are the natural habitat of these amphibians, which are often found on the water’s edge. The distinctive bull-like call made by the males during mating season explains how this frog earned its common name.

The bullfrog’s size can reach anywhere from 3.5 inches to 6 inches (9 cm to 15 cm) in body length with the legs adding another 7 inches to 10 inches (18 cm to 25.5 cm). The average weight is 1.1 pounds (0.50 kg) and its lifespan is from seven to nine years in the wild. The size varies and can be determined by environmental factors.

Bullfrogs live longer in a warmer habitat and seem to enjoy warmer weather, although they are also found in colder North American climates. Their diet consists of any creature that can literally be stuffed into their mouths. While mainly aquatic prey like fish and tadpoles are hunted, they also will eat small birds and mice.

Bullfrogs adapt relatively well to life in captivity and sometimes are kept as pets. In the southern United States and some Midwestern states, the frog is a food source. Larger bullfrog legs resemble chicken drumsticks and are the most commonly eaten part, followed by backs; both are usually fried and eaten. Traditionally, frog hunters use a canoe or flat-bottom boat with paddles. Spotlights are used to illuminate the shoreline, and hunters will catch them by hand.

Many school children around the world become familiar with this species in science class, where they are commonly used as dissection specimens. Three states in the United States — Iowa, Oklahoma and Missouri — consider the bullfrog their state amphibian. The species also has been introduced to South Korea, where it is considered an invasive species because of its large appetite and breeding capabilities.

Green frogs are often confused with bullfrogs, because of the species’ similar appearance. Green frogs, however, generally don’t get larger than 3 inches (7.5 cm) while bullfrogs are the largest species in North America. The best way to tell a bullfrog from another species is by sound. Bullfrogs have a deep, throaty tone that is generally not considered a “croak.” Their activity is mostly nocturnal, and many North American ponds fill with the sound of their vocalizations in the evening.