The American bullfrog is a large, green frog of North American ponds and lakes. A voracious predator, it has become one of the world’s most damaging invasive amphibians where introduced.
Interesting facts
- It is the largest frog in North America.
- Males make a deep ‘jug-o-rum’ call that can be heard over a kilometre away.
- Tadpoles can take one to three years to turn into frogs.
- Invasive bullfrogs threaten native frogs and spread the deadly chytrid fungus.
- Males have eardrums larger than their eyes; females’ are about the same size.
- Mark Twain’s story about a jumping frog inspired a famous frog-jumping contest in California.
Behaviour
Bullfrogs are mostly nocturnal. Males defend calling territories in summer, wrestling with rivals.
Breeding and young
Females lay up to about 20,000 eggs in a floating film on the water surface.
Threats and conservation
The species is abundant. It is hunted for frog legs and controlled where invasive.
Where to see it
- Ponds and lakes across the eastern United States
- Everglades National Park, Florida
- Farm ponds on summer nights, where males call
- Wetlands in southern Canada
Status source: IUCN Red List. Profile last reviewed September 2026.
