Courtesy of Carl D. Howe
North American Bullfrog
By John Fisher
That low-pitched, guttural “jug-o-rum” call often heard on warm summer evenings arising out of a nearby pond or creek emanates from one of Missouri’s newer state symbols, the North American Bullfrog (Rana catesbeiana), adopted June 5, 2005, as the state amphibian. The idea for a state amphibian originated with a fourth grade class at the Thomas B. Chinn Elementary School, a part of the Park Hill School District at Kansas City. Rep. Susan Phillips sponsored the bill. The students wrote notes to the legislators giving reasons why the bullfrog should be recognized as the state amphibian, made frog lapel pins, and even testified when the bill was in committee.
The bullfrog’s color ranges from green to olive to brown, with dark brown bands on the rear legs. This is the largest North American frog, reaching six inches in length and weighing a pound or more. Bullfrogs are also recognizable by the large, circular tympanic membrane, or eardrum, located on the frog’s skin behind each eye, and their large, powerful back legs. Bullfrogs can be found anywhere in Missouri with a suitable aquatic environment. They require permanent areas of water. Being an amphibian means much of its life is spent in the water, but they prefer feeding along shorelines. Males are very territorial and tenaciously guard their stretch of shoreline.
Bullfrogs will tackle about any prey they can swallow such as insects, small fish, crayfish, birds, mice, snakes, and even other frogs. They catch prey by waiting patiently then quickly grabbing the unfortunate creature with their powerful tongues. Adults and tadpoles are prey for birds such as herons and kingfishers, snakes, raccoons, and turtles.
The mating season for bullfrogs usually runs from mid-May to early July in Missouri. Males fertilize eggs as they are laid by the female. Each female usually lays twenty thousand eggs, which hatch in four or five days. Bullfrog tadpoles require just over a year to change into froglets. At this stage, they still have a tail but possess legs and breathe air through lungs. From this stage, another two to three years are required to reach adulthood. Bullfrogs usually live from seven to nine years.
Attempts to raise bullfrogs in ponds or other controlled settings for commercial production have met with limited success. Their territorial nature makes it difficult to keep large numbers in confined areas.
This story originally ran in the December 2008/January 2009 issue of Missouri Life. You can buy a copy here.
John Fisher is the author of Catfish, Fiddles, Mules, and More: Missouri’s State Symbols.
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