American Toad

Bullfrog by Dave Menke- US Fish and Wildlife (public domain)

CLICK TO PLAY BULLFROG SONG (MP3) Bullfrog call- USGS (public domain)

The Bullfrog is the largest frog in Connecticut. It is the largest frog in North America. Its skin can be green to yellow on top with gray mottling. Its belly is pale. Large round eardrums are visible behind its eyes. In the males these circular eardrums are larger than the eyes. The large webbed back feet can be conspicuous. Males have a yellow-colored throat while female bullfrogs have white throats. Bullfrogs can be 3 to 8 1/2 inches long and can weigh over a pound.

Bullfrogs range through the eastern and central parts of the US, and are present on the west coast. They are common throughout Connecticut. Bullfrogs live in permanent ponds, lakes and streams where they may lounge in the water or perch on the banks. Tadpoles live in the water until they reach maturity. Bullfrogs are active during the warm season and hibernate for the winter underwater, buried in the mud on the bottom of a waterbody. They are most active at night.

Adult bullfrogs are carnivorous. They can eat large prey (for frogs) and will consume creatures such as salamanders, crayfish, mice, small birds, and other frogs. They will hunt from water as well as from land. Immature bullfrogs, tadpoles, feed on plant matter.

Bullfrogs emerge from hibernation, usually around May, and are quiet until it is time to breed. Mating season peaks in July. Bullfrogs sing deep mating calls to attract a mate. Both genders croak. A male grabs the female around her chest with his front legs and clings until she lays her eggs in the water. He deposits sperm on top of them. The female bullfrogs produce up to 20,000 eggs in gelatinous masses attached to plants below the water surface. In a few days the eggs hatch into large greenish tadpoles. It takes about 4 months to 2 years for the tadpoles to absorb their tails, grow legs and develop lungs and they often overwinter in the tadpole form. Therefore it is not uncommon to see big bullfrog tadpoles in the spring. Tadpoles live only in the water. Adult bullfrogs can be in or out of water, but are highly aquatic.

Bullfrogs are solitary, except when they congregate in breeding waters in the summer. These big frogs make a very deep, thrumming call. They are the base-players of the amphibians, and their breeding areas are sometimes called booming grounds. Click the bullfrog call link below the photo for an example.

Frogs produce their calls by inflating part of their mouth lining under their throat with air through an opening in the bottom of their mouths. They then close off their mouths and nostrils and pump air between their lungs and this vocal sac over their vocal chords. The vocal sac of a calling frog is clearly visible as a bubble under his throat. A bullfrog makes a big bubble!

Sometimes younger, smaller bullfrogs are mistaken for green frogs.

Neat Facts

Froglegs as a meal for humans are usually the legs of bullfrogs. West coast bullfrogs were introduced to that region because of human desire for frog legs.

Bullfrogs can make 6 foot leaps.