American Bullfrog (Lithobates catesbeianus)
Order Anura, Family Ranidae, Genus Lithobates, Species L. catesbeianus. Ranids are characterized by powerful hind legs, smooth skin, and webbed feet.
Species
American Bullfrog (Lithobates catesbeianus)
Family
Order Anura, Family Ranidae, Genus Lithobates, Species L. catesbeianus. Ranids are characterized by powerful hind legs, smooth skin, and webbed feet.
Size
Snout-to-vent length ranges from 90 to 152 mm or more; females are often slightly larger than males.
Conservation
IUCN Least Concern with stable population trends, though invasive populations threaten native fauna.
Description
A massive and iconic amphibian known for its booming call and voracious appetite, serving as an apex predator in many freshwater ecosystems.
Key Features
Large size, absence of dorsolateral folds, large circular tympanum, and deep bass vocalization.
Physical Description
Robust, stout body with a broad head, large tympanum, well-developed muscular hind limbs, and extensive webbing on the hind feet.
Skin Texture & Coloration
Smooth to slightly rough dorsal skin, typically olive-green to brown with dark spots or mottling, and a creamy-white belly.
Distinguishing Features
Large tympanum (larger than the eye in mature males), absence of dorsolateral folds, and prominent skin fold wrapping around the tympanum.
Habitat
Large permanent water bodies including ponds, lakes, marshes, and slow-moving streams with abundant emergent vegetation.
Geographic Range
Native to eastern and central North America, but widely introduced globally as an invasive species.
Behavior
Highly aquatic, nocturnal to crepuscular, highly territorial males with aggressive calling and defense behaviors.
Diet & Feeding
Opportunistic ambush predators consuming insects, fish, small mammals, birds, and other amphibians.
Reproduction
Prolonged summer breeders; females lay large floating egg masses up to 20,000 eggs in quiet shallows.
Vocalizations
Deep, resonant, foghorn-like 'jug-o-rum' call audible from a long distance.
Life Cycle
Eggs hatch in a few days into tadpoles that may overwinter once or twice before undergoing metamorphosis into juveniles.
Conservation Status
IUCN Least Concern with stable population trends, though invasive populations threaten native fauna.
Toxicity & Defense
Non-toxic; defends itself through powerful leaps into water, camouflage, and defensive screaming.
Ecological Role
Acts as both a top aquatic predator controlling insect and vertebrate populations, and prey for larger mammals and birds.
Similar Species
Green Frog (Lithobates clamitans), which features distinct dorsolateral folds running down the back.
Observation Tips
Search at night along the margins of permanent ponds and lakes using a flashlight to catch the greenish eye-shine.
Handling & Safety
Handle with wet hands or gloves to protect their permeable skin; be cautious of strong leg kicks and powerful jaws.
Seasonal Activity
Active from spring through late autumn, overwintering buried in the mud at the bottom of ponds during freezing months.
Cultural Significance
Frequently featured in literature, folklore, and southern cuisine as frog legs, and widely studied in biology classrooms.
Interesting Facts
Can consume prey nearly its own size, including snakes, birds, and small rodents.