Species

American bullfrog

Lithobates catesbeianus

North America's largest frog, whose deep, rumbling call carries across ponds on summer nights.

Photo Cephas (opens in a new tab) / Wikimedia Commons, CC BY-SA 3.0 (opens in a new tab)

At a glance

Size: About 9 to 15 cm long; up to 20 cm
Habitat: Ponds, lakes, slow streams and reservoirs with permanent water
Diet: Insects, crayfish, fish, frogs, snakes, small birds and mice
In Georgia: Common statewide
Voice: A deep "jug-o-rum" rumble
Rabies vector: No

Identification

Key marks: Large and green to olive; a fold of skin that curves around the eardrum rather than running down the back; males have eardrums larger than their eyes
Told apart from: Green frog, which is smaller with ridges running down the back
Where to look: At the edges of ponds; shining eyes in torchlight at night

Behaviour

Bullfrogs are sit-and-wait predators that eat almost anything they can swallow. Males defend calling territories in summer. The tadpoles can take two years to become frogs.

Why they matter

In the East bullfrogs are a native top predator of ponds and a food source for herons, snakes and otters. Released in the West, they have become an invasive threat to native frogs.

Reproduction and lifecycle

Eggs — Up to 20,000, in a floating film
Hatching — In a few days
Tadpoles — Large; take one to two years to change
Maturity — In two to four years
Lifespan — Around 8 to 10 years
Calling — On summer nights

Living around people

Never move bullfrogs or tadpoles to new ponds; in some places they wipe out native frogs.

Misconceptions

Big tadpoles in winter are stuck. Bullfrog tadpoles normally spend a winter or two as tadpoles.

Related species

Seasonal activity

When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.

Breeding and active nests by month for this species
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Breeding	Jan: no	Feb: no	Mar: no	Apr: no	May: no	Jun: no	Jul: no	Aug: no	Sep: no	Oct: no	Nov: no	Dec: no
Active nests	Jan: no	Feb: no	Mar: no	Apr: no	May: no	Jun: no	Jul: no	Aug: no	Sep: no	Oct: no	Nov: no	Dec: no
Notes	Under water	Under water	Emerging	Active	Calling	Breeding	Breeding	Young frogs	Feeding	Active on warm days	Under water	Under water

Where it lives

Recorded in 69 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.

Canada

Mexico

If you found one

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