The Green Frog is one of three species
of amphibians found on Block Island. They are distinguished
from similar looking Bull Frogs (which do not exist
on Block Island) by the lateral ridges running along
the outer edges of their back.
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Green Frogs:
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grow to about 3 inches. |
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have webbed hind feet
and dark bar markings on their hind
legs. |
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range in coloration from
green to olive to brownish above, and
usually have a distinct lime-greenish
to yellow chin and throat. |
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have a whitish belly,
sometimes with darker mottling. |
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have been known to live
up to 10 years in captivity. |
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Green Frogs are common throughout Block Island and
Rhode Island. They occur in a variety of freshwater
habitat types: large and small ponds, streams, marshes
and swamps, and long lasting vernal ponds.
Green Frogs have interesting adaptations that prepare
them well for their habitat. Their powerful hind
legs make them fantastic jumpers for escaping predators
or leaping for food; their webbed hind feet make
them good swimmers. With large protruding eyes,
Green Frogs can be almost completely submerged while
waiting for prey. Interestingly, these large eyes
can be pulled down into the eye socket thus aiding
in swallowing by pushing the food down the throat.
The tympanum (large disk placed below and to the
rear of the eye) is an external ear drum that allows
excellent hearing in their watery environment.
Green Frogs:
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are considered "aquatic" frogs; they must
stay in or near water to avoid desiccation.
These watery territories are relatively small;
individuals are often identified repeatedly
in the same area. |
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are opportunistic feeders,
thus eating whatever variety of insects, larvae
and algae exists in their wetland or happens
to fly by. |
Green Frogs, like all amphibians, lay eggs which
hatch into tadpoles and metamorphose into tailless
adult frogs.
Green Frog populations are fairly stable throughout
RI. Freshwater wetland regulations protect their
habitats, and Green Frogs appear to be tolerant
of development and habitat changes - as long as
the habitat stays wet and free of toxins.
In areas where Green Frogs (and other frog species)
are found with disturbing physical deformities,
they may be acting as an indicator of the presence
of pollutants, or other degradations of the ecosystem
due to biological or radiation imbalances. To learn
more, go to: www.pca.state.mn.us/hot/frog-faq.html
or http://news.minnesota.publicradio.org/features/199708/04_losurem_frog/.
Perhaps the most notable feature of a Green Frog
is its loud twangy vocalization - "guungk" - which
sounds like a bass banjo string being plucked. This
loud twangy "guungk" can be heard coming from ponds
and wetlands all over Block Island. Although the
Green Frog is not a particularly wary animal, enjoying
that voice may be the closest one gets to a Green
Frog encounter on Block Island.
There are 2 subspecies
of Green Frog.
- *Ranus clamitans
melanota is known as Green Frog and
is native throughout eastern and central
North America; including southern portions
of Ontario to Nova Scotia, Canada, and
extending as far south as northern parts
of the states of Georgia and Alabama.
- *Ranus clamitans
clamitans, known as Bronze Frog, is
found in the southeast and Gulf States
of the United States.
*(Ranus is the Latin for "frog"; clamitans
means "loud calling") |
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