Page 116 - A Field Guide to Fairfax County's Plants and Wildlife
P. 116
rican Bullfrog

(Lithobates catesbeianus)


Virginia’s largest native frog,
males range from 8.5 to 18
centimeters, and females from
9 to 20 centimeters. Adults are
drab olive-green with lighter
underparts. Both males and
females have an enlarged eardrum (called a tympanum) behind each eye, but
the eardrums of males are larger than the females’. Bullfrogs are active mainly
at night. They are solitary and very territorial. Male bullfrogs claim and defend
their territories by calling, aggressive posturing and even fighting with other
males. In Virginia, American Bullfrogs breed from late spring to early fall. After
mating, the female lays up to 20,000 eggs on the water’s surface. The eggs
hatch into tadpoles (also called “pollywogs”) in five days. Bullfrog tadpoles
can grow to be quite large, and may take one to two years to metamorphose
into adults. In winter, bullfrogs dig themselves into the mud and hibernate.

The deep call of the male American Distribution and Habitat
Bullfrog (“Jug-a-rum…jug-a-rum”)
resembles the mooing of a cow American Bullfrogs are found in all
(hence its name) and can be heard five physiographic provinces. They
up to a kilometer away. live in freshwater ponds, lakes and
swampy areas.
Did you know that a group of frogs is
called an “army?” Role in Food Web

Tadpoles are omnivorous and can
be cannibalistic. Adults will eat
almost anything they can overpower
and stuff into their huge mouths.
Insects, crayfish and other bullfrogs
are the most important prey items.
Large bullfrogs have even been
known to catch and eat birds!
Predators include fish, snakes and

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