|Common Name:||American Bullfrog|
|Scientific Name:||Lithobates catesbeianus (formerly Rana catesbeiana)|
|Genus:||Lithobates is Greek, Litho means "A stone", bates means "One that walks or haunts."|
|Species:||catesbeianus is in honor of Mark Catesby (1679-1749)|
|Average Length:||3.5 - 6 in. (9 - 15.2 cm)|
|Virginia Record Length:|
|Record length:||8 in. (20.3 cm)|
PHYSICAL DESCRIPTION: This is the largest native North American frog species in Virginia *1014* *11407*. Lengths range from 85-200mm (3.5-6 in) *1014* *11407*. The dorsal coloration is green, olive, or brown *1014* *11407*. It is typically plain but may have a net like pattern of gray or brown on the green background *11407*. The ventrum is whitish, often mottled with gray. This species lacks the dorsolateral folds but does have a thin fold or ridge along the border of the tympanum *1014* *11407*. Males are generally smaller than females, have a yellowish wash on their throat, and a larger tympanum, thumb, and forearm *1014*. The male breeding call is a deep, full series of notes best described as "jug-a-rum". Male has a single internal vocal sac that forms a flattened pouch beneath the chin when inflated *11407*.
REPRODUCTION: This species breeds from the late spring to early fall *11407*. Males are territorial. Mating success is influenced by the quality of the territory *11406*. The male breeding call is a deep, full series of notes best described as "jug-a-rum" *11407* *1014*. Females lay one or two clutches per season *11406*. Average clutch size is 12,000 eggs *1014* *11406*. Clutches are laid in a film on the water surface *11406*. Eggs hatch in approximately 5 days. Tadpoles can be very large, 125-150 mm *1014*. Metamorphosis usually takes 1 year, larvae will overwinter in ponds *1014* *11406*. Larval survivorship is <18% *11406*. This species typically reaches sexual maturity one year after metamorphosis *11406*. In mountain localities, transformation may take 2 years *11284*.
BEHAVIOR: This is a wary and solitary species that prefers large ponds, lakes, and still portions of streams *1014*. Males of this species defend territories typically within vegetated areas of ponds. Defending behaviors include encounter calls, postural displays, chasing the intruder, and combat. Size and age strongly determine territory success *11406*. This is a voracious predator feeding on insects, crayfish, small mammals, snakes and other frogs *11406* *1014*. Experiments have demonstrated that this species has the ability to orient to stellar patterns or the moon *11406*.
LIMITING FACTORS: This species requires medium to large permanent bodies of water to meet their one to two year early developmental period *11284*.
POPULATION PARAMETERS: Life expectancy for female frogs in a study in Michigan was found to be 4 years. The longevity record for a specimen in captivity was 16 years *11406*. Larval survivorship is typically <18% *11406*.
AQUATIC/TERRESTRIAL ASSOCIATIONS: This species prefers large ponds, lakes and quiet sections of streams *1014*. It prefers larger bodies of water than most frogs *11407*. It is usually found in aquatic vegetation or snags in which it can hide *11407* *11406*. Clutches of eggs are laid in still shallow water *11406*. OTHER:
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|Bullfrog Tadpole||Bullfrog vs. Green Frog||Green Frog(top) and Bullfrog (bottom)|