American Bullfrog (Rana catesbeiana)


Class: Amphibia
Order: Anura
Family:    Ranidae
Size:    Length: 3.5 to 8 inches (9 to 20 cm)
Weight: 2 ounces (57 g)
Diet: Many different animals including snakes, insects, worms, bats, shellfish, minnows, shellfish and minnows
Distribution: North America
Young:  10,000 to 20,000 eggs
Animal Predators:  Water snakes, snapping turtles, large fish, herons, opossums, skunks and raccoons
IUCN Status: No special status
Terms: Young: Tadpoles
Lifespan: Up to 15 years in the wild and up to 8 months in captivity



·       Bullfrogs close their nostrils underwater but continue to breathe through their skin.

·       Bullfrogs are capable of leaping three to six feet (one to two metres).

·       Only the hind feet of a bullfrog are webbed.

·       Bullfrogs have teeth in the roof of their mouths and tongues that can easily flip prey into them.

·       When bullfrogs catch prey on land, they often drag it into the water to eat it.



Bullfrogs are the largest frogs in North America and unlike other frog species, males are larger than females. It is easy to see whether a bullfrog is male or female by looking at the tympanic membrane. The tympanum, which is the outer ear of the frog, is a round spot located behind the eye. If it is larger than the eye, the frog is a male. In females, the tympanum is the same size or smaller than the eye. As well, during mating season the male’s throat turns yellow, while the female’s stays white. By inhaling air, bullfrogs can make their bodies puff to a considerable size in an effort to appear larger when they feel threatened by predators. 



Bullfrogs live in water and prefer the shallow, warm and still waters of a lake, marsh, river, swamp or pond. In colder weather, they bury themselves in mud and hibernate. American bullfrogs are found from eastern Canada south to Florida, from the east coast of the United States across the Great Plains to the Rocky Mountains. They were introduced to California and Colorado in the early 1900s, but their introduction has interfered with native species of wildlife.


Feeding Habits

Bullfrogs are serious predators. They eat snakes, insects, worms, shellfish, minnows and even other frogs. Bullfrogs usually sit and wait for prey to pass by. Then, using their incredibly strong hind legs, they leap out of the water to catch the prey, which could be anything from a butterfly to a bat.



During mating season, males attract females by calling to them. The female lays up to 20,000 eggs in a foamy mass that floats on the water’s surface. Four to 20 days after fertilization, the tadpoles begin to hatch. The tadpoles develop quite slowly, taking two to three years to fully mature, and toward the end of their development resemble frogs with large tails. Male bullfrogs vigorously defend their tadpoles from predators. 



The bullfrog is named for the call of the male, which resembles the bellow of a bull. It has been described as sounding like “jug-o-rum” and can be heard up to one kilometre (0.6 mile) away. Males defend their territories aggressively, physically attacking intruders.



American bullfrogs enjoy healthy populations and are not of conservation concern. 



American Bullfrog Wildlife Fact File, IM Pub, US