Animal Bytes
 
Bullfrog
 
Common Name: bullfrog
   
Class: Amphibia
   
Order: Anura
   
Family: Ranidae
   
Genus species: Rana catesbeiana

 

FAST FACTS
FUN FACTS
ECOLOGY & CONSERVATION
BIBLIOGRAPHY
   
 
Fast Facts
Description: Green to greenish brown; bullfrogs of the southern US are often spotted; irises of gold or brown; both head and body are flattened and broad; the tympanum (eardrum) of the male is larger than the female's
   
Size: Snout to vent length: 9-15 cm (2.5-6 in); record 20 cm (8 in)
Legs length: 17-25 cm (7-10 in)
   
Weight: Up to 500 g (17.5 oz)
   
Diet: Voracious appetite; will eat almost anything that moves and that it can swallow - including invertebrates and small vertebrates such as mammals, birds, reptiles, fish, and even turtles and other frogs
   
Incubation: 20,000 eggs produced by a single large female hatch in four days or less
   
Sexual maturity: 2 to 4 years
   
Life span: Average 4 to 5 years
   
Range: Nova Scotia to Central Florida, west to Wisconsin and the Rockies; introduced to British Columbia and California
   
Habitat: Vegetation along edge of large, slow moving bodies of freshwater
   
Population:  
   
Status: Not listed by USFWS or CITES
   
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Fun Facts
1. Bullfrogs are capable of leaping 1 to 2 m (3-6 ft).
   
2. Bullfrogs are territorial and protect their territories by calls, displays, chases, jump attacks, and even wrestling. Females are attracted to males with territories that provide the most food.
   
3. A female bullfrog can lay up to 25,000 small eggs that are held together at the surface of the water.
   
4. Hearing is one of the most important senses to a frog. Male bullfrogs chorus at breeding ponds; females also give aggressive and reciprocation calls.
   
5. Bullfrogs have teeth in the roof of their mouth and a muscular tongue capable of flipping prey into their mouth.
   
6. Bullfrogs may remain at the tadpole stage for up to 2 years. A longer tadpole stage means a larger frog after metamorphosis, which usually means a better chance of survival.
   
7. Bullfrogs close their nostrils and continue to absorb oxygen through their skin while under water.
   
8. In general, frogs have smooth skin while toads have textured skin.
   
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Ecology and Conservation
 

Where bullfrogs occur naturally, they are common and help keep populations of insects in check. But they have been introduced into areas of the western United States where, because of their appetite, they are capable of reducing or destroying local populations of native species. Their populations can increase to become out of balance with the species native to those habitats because often they have no natural predators and their skin secretions make them unpalatable to many animals. Bullfrogs, like all amphibians, have porous skin and respond quickly to changes in the environment. The health of their populations can be an indicator of the health of the environment.

   
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Bibliography
 

Beringer and Johnson. 1995. Herpetological Review. 26(2):98.

   
  Conant and Collins. Reptiles and Amphibians of Eastern and central North America. Boston: Houghton Mifflin Co., 1991.
   
 

Dickerson, Mary. The Frog Book. New York: Dover Pub. Inc., 1969.

   
  Duellman and Trueb. Biology of the Amphibians. Baltimore: Johns Hopkins Univ. Press, 1986.
   
  Stebins and Cohen. A Natural History of Amphibians. 1995. Princeton University Press, Princeton, New Jersey.
   
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