The American bullfrog is famously said to make a “jug-o-rum” call.
This deep, repeated call is produced mainly by males during the breeding season. It helps advertise a male’s presence and territory to other bullfrogs and can attract females. The sound is amplified by the bullfrog’s vocal sacs, which inflate at the sides of the head.
“Jug-o-rum” is an English sound imitation rather than a biological term used worldwide. Different languages represent the call differently, and individual bullfrogs may vary in pitch and rhythm. The American bullfrog should also not be confused with the green frog, whose call is commonly described as a single plucked-string note.
Bullfrogs are among North America’s largest frogs. They are ambush predators that eat insects, fish, birds, reptiles, amphibians and small mammals. Their loud calls are especially conspicuous around ponds, marshes and slow-moving waterways during warm weather.