Subscribe Now! National Geographic Magazine $15
Visit our Online Shops

Sign up for free

Newsletters

Once a month
get new photos
and expert tips.

American Bullfrog
Rana catesbeiana

Photo: A bullfrog in mid-jump
American bullfrog
Photograph by Bianca Lavies

American Bullfrog Profile

The baritone call of the bullfrog is so deep and resonant, it resembles the mooing of a cow, hence its name. Only males emit this trademark "jug-o-rum" bellow, and their choruses can be heard during the day or night.

The largest of all North American frogs, this giant can grow to a length of 8 inches (20 centimeters) or more and weigh up to 1.5 pounds (750 grams). Even the tadpoles of this species can reach 6.75 inches (17.2 centimeters) in length.

They are among the most wide-ranging of all North American amphibians, found in freshwater ponds, lakes, and marshes from Nova Scotia, Canada, throughout the continental United States, and as far south as Mexico and Cuba. They have even found their way to Europe, South America, and Asia.

Bullfrogs are typically green or gray-brown with brown spots and have easily identifiable circular eardrums, or tympanum, on either side of their heads.

Nocturnal predators, they will ambush and eat just about anything they can fit in their ample mouths, including insects, mice, fish, birds, and snakes. They sit quietly and wait for prey to pass by, then lunge with their powerful hind legs, mouths open wide.

Males are highly territorial and will aggressively guard their land. Females are slightly larger than males.

Fast Facts

Type: Amphibian
Diet: Carnivore
Average lifespan in the wild: 7 to 9 years
Size: (adult female) 3.5 to 6 in (9 to 15 cm)
Weight: 1.1 lb (0.50 kg)
Group name: Army or colony
Did you know? A female bullfrog can lay as many as 20,000 eggs, which float in a clump on the surface of the water.
Size relative to a tea cup:
Illustration of the animal's relative size

Multimedia

Frog Features

Photo: Sonoran desert frog

The Fragile World of Frogs

Frogs have thrived worldwide for nearly 200 million years, but they are quickly beginning to vanish. Find out why in this multimedia feature from National Geographic magazine.

Photo: A rare and endangered blue poison dart frog

Kids: Frog Creature Feature

Get fun facts on red-eyed tree frogs, plus video, audio, photos, and more at National Geographic's Kids site.

Photo: American bullfrog

Wild Rivers

Visit the rivers and streams of the southeastern U.S., home to some of the most species-rich freshwater systems on Earth, in this Wild World feature.

Photo: American bullfrog

Photo of the Day: Tastes Like Chicken

See a baby bullfrog gulping down a freshly caught dragonfly.

Photo: Tree frog

Virtual World: Rain Forest

Bring your flashlight and visit the jungles of Borneo at night in this online virtual tour.

Other Frogs

Map: Locator map for the American bullfrog
 American Bullfrog range

Special Advertising Sections

Photo: Puerto Escondido

Mexico via Pacifico

Find unusual vacation spots and journey through Mexico.

Photo: Caernarfon Castle in Wales

Photo Contest

Enter for a chance to win a trip to Africa with an NG expert.

Amphibians Right Rail

Get the Latest Headlines

Photo: Blue poison dart frogs

Make us your online news source.

Get Animal Pictures

Photo: Amphibians mating

Get your daily dose of photos.

For Kids!

Photo: A cartoon dog

It's no stretch to find fun facts on our Kids site!

Six Degrees Book and DVD

Image: Six Degrees DVD and book

Get an eye-opening warning of the dangers of climate change, one degree at a time.