What Does a Bullfrog Sound Like? Calls, Meaning and Season
An American bullfrog sounds like a deep, low-pitched croak, written as “jug-o-rum” or “roo-roo-room.” Males make it, and Animal Diversity Web says it can be heard for over a kilometre. Males also give a shrieking alarm call when leaping into water and a short “phfoot” aggression call, according to North Carolina wildlife officials. Calling runs from late spring through summer, day or night.
A bullfrog call is hard to miss. On a warm night near a pond it can sound like a low, rumbling bass drum, repeated at intervals. Several different sounds exist, and each means something different.
This page covers the American bullfrog. It describes each call, when and where you will hear it, and how sources differ on season and size. For its diet, see do bullfrogs eat mice.
How this was made: prepared with AI assistance and checked against the sources listed at the end. Images are AI-generated illustrations, not photographs of real animals or products.
Key Takeaways
- The main call is a deep, low-pitched croak, rendered as jug-o-rum.
- Males make the main call. It can be heard over a kilometre away (Animal Diversity Web).
- Other sounds include an alarm shriek, a spitting aggression call and a female scream.
- Calling is heard from late spring into summer, at any time of day or night.
- Males defend stretches of shoreline of about 3 to 25 metres.
- Sources differ on season and size, so ranges are shown with names.
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The bullfrog call, sound by sound
The North Carolina Wildlife Resources Commission describes a booming, low-pitched croak, written as “roo-roo-room” or “jug-or-rum.” The University of Florida calls it a deep, low-pitched “jug o’rum.” The Illinois Department of Natural Resources writes “jug-o-rum” or “br-wum.”
Bullfrogs have more than one sound. The table below lists those named by wildlife agencies.
| Call | How it sounds | Source |
|---|---|---|
| Main male call | Deep, booming croak: jug-o-rum or roo-roo-room | NC Wildlife; Animal Diversity Web |
| Alarm call | Shrieking cry as the frog leaps into water | NC Wildlife |
| Aggression call | Abrupt, spitting phfoot | NC Wildlife |
| Female call | High-pitched scream | NC Wildlife |
| Fright sound | Cat-like meow when frightened | University of Florida |
How far does the call carry?
Animal Diversity Web says the male’s low-frequency call is audible for over one kilometre. That is far enough to be heard across a large pond or lake.
Males also have a visible clue. The round eardrum, called the tympanum, is much larger than the eye in males. In females it is as large as or smaller than the eye.
When do bullfrogs call?
North Carolina wildlife officials say males call mostly alone from late spring into summer, at any time of day or night. Several males may call across a pond at once, especially after heavy rain.
Breeding windows differ by source and place. Animal Diversity Web gives May to July in the north and February to October in the south. The University of Florida gives February through October. Illinois gives late April through August.
| Source | Breeding or calling window |
|---|---|
| Animal Diversity Web | May to July (north); February to October (south) |
| University of Florida | February through October |
| Illinois DNR | Late April through August |
| NC Wildlife | Late spring into summer |
Do bullfrogs call in a chorus?
Not in the way many small frogs do. North Carolina officials say bullfrogs do not sing in chorus. Males call mostly alone, though several may call at once across a pond.
Animal Diversity Web says adult males defend territories of about 3 to 25 metres of shoreline and will wrestle rivals.
Where to hear one
Bullfrogs live in warm, still, shallow water such as lakes, ponds, rivers and bogs, says Animal Diversity Web. Illinois reports them statewide, mostly at the water’s edge.
The species is native to eastern North America, from Nova Scotia to central Florida and across the Great Plains. Animal Diversity Web also lists introduced populations in California, Colorado, southern Europe, South America and Asia.
Size and looks
The bullfrog is the largest frog native to North America. Sources give different sizes. Animal Diversity Web lists a typical 90 to 152 mm and up to 203 mm. North Carolina gives 6 to 8 inches and 2 to 3 pounds. Illinois gives 3.5 to 6 inches.
The University of Florida notes large eardrums behind each eye and fully webbed hind feet, except the last joint of the longest toe. For lifespan, read how long do American bullfrogs live.
Related reading
The adult bullfrog eats almost any animal it can swallow. Illinois says crustaceans and insects make up most of the diet. For more, see what do frogs eat.
Tadpoles take about 14 months to transform in Illinois, and one to three years according to Animal Diversity Web. Learn the stages in the frog life cycle.
Frequently Asked Questions
What sound does a bullfrog make?
Males make a deep, booming croak written as jug-o-rum or roo-roo-room. They also shriek when startled.
Why do bullfrogs croak at night?
Calling happens at any time of day or night, according to NC wildlife officials. Males also defend shoreline territories, says Animal Diversity Web.
Do female bullfrogs croak?
The NC Wildlife page describes the female call as a high-pitched scream, not the deep male croak.
How loud is a bullfrog?
Animal Diversity Web says the male call can be heard for over a kilometre. We found no source giving a decibel figure.
When are bullfrogs loudest?
From late spring into summer, and especially after heavy rain, when several males may call at once.
Why does a bullfrog scream?
NC Wildlife describes a shrieking alarm call when a bullfrog leaps into water. The University of Florida notes a cat-like meow when frightened.
Bottom Line
The bullfrog’s voice is one of the most recognisable sounds of a summer pond. A deep jug-o-rum means a male is holding his patch of shoreline.
For more frog sounds and behaviour, see how does a frog reproduce and what frogs live in a pond.
Sources
- Animal Diversity Web: Lithobates catesbeianus (American bullfrog), accessed Call, range, territory, size
- North Carolina Wildlife Resources Commission: Bullfrog, accessed Call types, season, size
- University of Florida IFAS: Rana catesbeiana, accessed Call, identification, breeding window
- Illinois Department of Natural Resources: American bullfrog, accessed Call, season, size, tadpoles, diet
