American Bullfrogs

The American Bullfrog is native to every state east of the Mississippi River. They are nocturnal and the largest true frog found in North America. They can be up to 8 inches long and weigh over a pound. Even their tadpoles are large, some reaching up to almost 7 inches long. The croaking of a bullfrog is a familiar sound of spring and summer. Only the males croak producing a low rumbling “jug-o-rum” call which can be heard a mile away. They croak to attract mates and to establish territory.

Bullfrogs need permanent sources of fresh water like lakes, ponds, and slow-moving streams. They need permanent water because unlike many frogs their tadpoles take 2 to 3 years to grow before metamorphosing into an adult. Their color, ranging from brown to different shades of green with random mottling of darker gray, provides camouflage allowing them to blend with the plants in their environment. Their back feet are webbed. They have good vision with large bulging eyes that sit at the top of their head giving them a wide view. This is important since they can’t move their heads from side to side. Their ear, called the tympanum, is a round circle on the side of their head near the eye. They have a spring-loaded tongue and powerful jaws. Bullfrogs are carnivorous opportunistic ambush predators that sit quietly waiting for prey to come close. They eat just about anything that fits in their mouth including mice, salamanders, crayfish, toads and other frogs, insects, tadpoles, snails, and small fish, birds, lizards, and snakes. If their meal doesn’t completely fit in their mouth, they use their hands to finish stuffing it in.  

Bullfrogs are an important member of Ohio’s ecosystem. A variety of aquatic and terrestrial wildlife, including great blue herons, great egrets, belted kingfishers, snapping turtles, racoons, and river otters, feed on bullfrog adults, juveniles, tadpoles, and eggs. They provide insect pest control. And they provide some economic benefits when used as research specimens and as a food source for humans. Artificial light disrupts the nighttime croaking of these frogs, which is a part of their breeding ritual, interfering with their reproduction and leading to reductions in their populations. Let’s help the bullfrog by turning off all unnecessary lights.