Skip Navigation Links

Bullfrog - Rana catesbeiana

Frog Tumbnail Image Jug o-Rum Rum

Download

Description & Identification:

Largest frog in North America, may reach 8" (20cm). Dorsum is dark olive green to almost black with indistinct markings; the hind legs are frequently marked by conspicuous dark bands; the head may be the same color as the back or it may be dark to bright green; underside is white with a mottling of black; throat of males may be bright yellow and tympanum in males is larger than the eye (equal or smaller in females); reduced dorsolateral ridges that extend from the eye and around the tympanum but not on the trunk; webbing of hind toes does not extend to tip of longest toe. Skin is smooth.

Development:

Bullfrogs breed when the water temperature exceeds 70 degrees F (21 degrees C), generally from April through the summer months. The eggs are black above, white below, and are laid in a jelly mass at or near the surface. The tadpoles are large, up to 3" (76mm); greenish brown flecked with black; upper tail fin is spotted with black, lower is not. Tadpoles may not metamorphose until after their second year.

Habitat & Behaviors:

This is an aquatic species preferring larger, permanent bodies of water such as lakes, ponds, bogs, and sluggish streams, where they transform through all stages of their life cycle. This large frog may feed on any other animals small enough for it to swallow, including other frogs, snakes, and baby ducks. Male bullfrogs are territorial and may occassionally enter into mock battles if they find themselves face to face, whereupon both stand up on their back legs and embrace until falling over. When one is determined the victor, the loser moves on.

Similar Species:

Bronze frogs have more pronounced dorsolateral ridges that end farther back on the body, yet not reaching the groin. River frogs have white spots on the jaw and lip areas, and a highly motted underside. Pig frogs have webbing on hind toes that extends to tip of largest toe.

Voice Call:

A deep, resonant, "jug-o-rum" or shortened "o-rum" which can be heard for great distances; generally call from the bank from April through summer and into September.

Frog Observation Data

This frog has been observed at the following locations. Click on the map to view the data.

Map showing observation locations for this frog

Frog Image Slideshow

Frogs Being Monitored

Select a frog to view species details, hear audio samples and view photographs.

Thumbnail Image of Frog
Barking Treefrog Hyla gratiosa
Thumbnail Image of Frog
Bronze Frog Rana clamitans clamitans
Thumbnail Image of Frog
Bullfrog Rana catesbeiana
Thumbnail Image of Frog
Cuban Treefrog (invasive) Osteopilus septentrionalis
Thumbnail Image of Frog
Eastern Narrow-mouthed Toad Gastrophryne carolinensis carolinensis
Thumbnail Image of Frog
Eastern Spadefoot Toad Scaphiopus holbrooki
Thumbnail Image of Frog
Giant Toad (invasive) Bufo marinus
Thumbnail Image of Frog
Gopher Frog Rana capito aesopus
Thumbnail Image of Frog
Green Treefrog Hyla cinerea
Thumbnail Image of Frog
Greenhouse Frog (invasive) Eleutherodactylus planirostris planirostris
Thumbnail Image of Frog
Little Grass Frog Pseudacris ocularis
Thumbnail Image of Frog
Oak Toad Bufo quercicus
Thumbnail Image of Frog
Pig Frog Rana grylio
Thumbnail Image of Frog
Pinewoods Treefrog Hyla femoralis
Thumbnail Image of Frog
River Frog Rana heckscheri
Thumbnail Image of Frog
Southern Chorus Frog Pseudacris nigrita verrucosa
Thumbnail Image of Frog
Southern Cricket Frog Acris gryllus dorsalis
Thumbnail Image of Frog
Southern Leopard Frog Rana sphenocephala
Thumbnail Image of Frog
Southern Toad Bufo terrestris
Thumbnail Image of Frog
Spring Peeper Pseudacris crucifer bartramania
Thumbnail Image of Frog
Squirrel Treefrog Hyla squirella

Calendar of Events