A Study of Habitat Preference by
Different Types of Frogs in Vernal
Pools in Massachusetts
By Andrew Kalaris and Rebecca
Zoller
Two Frogs Studied

GREEN FROG
vs.

WOOD FROG
Distribution
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Green frogs are widely distributed in Canada
from Nova Scotia west through Quebec and
southern Ontario (Degraaf and Yamasaki
2001). Their range covers the eastern half
of the United States, occurring as far west
as eastern Minnesota, Iowa, Missouri,
Oklahoma, and Texas (Klemens 1993). They
range as far southeast as northern Florida.

http://www.uri.edu/cels/nrs/paton/LH_gree
n_frog.html

Wood frogs range farther north than any
other amphibian in North America, reaching
69° latitude within the Arctic Circle (Martof
and Humphries 1959; Klemens 1993). Their
northern range limit corresponds with the
edge of the northern limit of spruce forests.
Wood frogs are found throughout the
northeastern United States, the Great Lakes,
and throughout Canada into Alaska; their
range covers approximately four million
square miles (Martof and Humphries 1959).
They also range south along the
Appalachian Plateau to extreme northern
Georgia, and eastern Tennessee and
Kentucky, with disjunct populations occur in
Alabama, Arkansas, and Missouri (Klemens
1993).
http://www.uri.edu/cels/nrs/paton/LH_wood
_frog.html
Habitat Preference

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Green frogs are found in:
Swamps
Wooded swamps
Ponds
Lakes
Marshes
Bogs
Banks of slow moving rivers
and streams
(http://animaldiversity.ummz.u
mich.edu/site/accounts/inform
ation/Rana_clamitans.html)
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Wood Frogs are found in:
Woodlands during the summer
Under stones, stumps, leaf
litter in winter
Wood ponds and vernal pools
while breeding
(http://animaldiversity.ummz.u
mich.edu/site/accounts/inform
ation/Rana_sylvatica.html)
Description
Green Frogs:
“Green frogs are green, greenish brown,
brownish, yellowish green and olive, with
some rare individuals being blue. They are
generally brighter in front with small
irregular black spots. Their legs have dark
transverse bands. They are yellowish or
white below, and males usually have a
bright yellow throat. The tympanum
(eardrum) is large; in males the tympanum
is much larger than the eye and females
tend to have a tympanum the same size as
the eye. The dorso-lateral ridge is well
defined and extends from the back of the
eye posteriorly down the body. The toes are
well webbed and the first fingers do not
extend beyond the second. The tibia and
femur are equal to ½ of the body length,
which is 7.5 to 12.5 cm for adults. ”

http://animaldiversity.ummz.umich.edu/site/acco
unts/information/Rana_clamitans.html
Wood Frogs:
“Wood frogs range from 3.5 to 7.6 cm. Females
are much larger than males. This species
exhibits a number of color morphs, usually
browns, tans and rust, but can also be
found in shades of green and gray. In all
cases however, they can be distinguished by
a black patch that extends over the
tympanum to the base of the front limb. It is
this characteristic that causes them to be
referred to as the frog with the "robber's
mask". They are also known to have a white
spot on the upper lip. Most specimens have
a light yellowish brown middorsal lateral
fold. The underparts of the frogs are
yellowish and sometimes greenish-white,
with male frogs having more brilliant colors
on the ventral aspect of the legs.”

http://animaldiversity.ummz.umich.edu/site/
accounts/information/Rana_sylvatica.html
Food Habits
Green Frogs eat:
 Insects and small
invertebrates – slugs,
snails, crayfish,
spiders, flies,
caterpillars, snakes,
and frogs from the
water and land
Wood Frogs eat:
 Insects and other
small invertebrates –
spiders, beetles,
bugs, slugs, snails
Reproduction
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Green Frog
“Green frogs breed in semi-permanent
or permanent freshwater habitats of
various sizes and vegetation structure.
Typical breeding sites include lakes,
ponds, margins of rivers, streams,
bogs, swamps, and vernal ponds with
long hydroperiods”


http://www.uri.edu/cels/nrs/paton/LH_
green_frog.html
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Wood Frog
“Wood frogs prefer forested vernal
pools (semi-permanent and temporary
flooded ponds) for breeding. However,
observers have noted wood frogs
breeding in grassy pasture ponds,
ditches, fens, wooded swamps,
flooded meadows (Klemens 1993)
and, in Maine, abandoned beaver
flowages, old gravel pits, cattail
swamps, and slow moving streams
(Knox 1999). The common
characteristic amongst these
waterbodies is that they are typically
fishless. Wood frogs bred in both
closed and open-canopy wetlands”
http://www.uri.edu/cels/nrs/paton/LH_
wood_frog.html
Areas of Study
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We selected two areas of study, the
Landfill vernal pool and the shallows of
Lake Romeyn to set our traps.
We checked the traps the 21st, 22nd, and
23rd of May, 2005.
The weather was cold during the times we
attempted to catch frogs
Results
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We caught two fish – but no frogs.
The unusually cold spring clearly killed or caused many frogs to
remain inactive.
Disturbance might have scared off the frogs when we attempted to
catch them using nets
In retrospect, we should have increased the length of time we set
traps in, to avoid this type of massive bias and error.
Setting more traps in more pools would have given us a better
chance to collect some amount of data.