Tennessee is home to 21 species of frogs and toads.
What is the difference between a frog and toad? In general:
Frogs have smooth moist skin, can jump very well, and usually are found close to a water source even as adults.
Toads have dry warty skin, make short hops, and may be found far from water as adults. However, technically toads are frogs! Frogs and toads belong to the group of animals known as amphibians.
Eastern Spadefoot
American Toad
Fowler’s Toad
Northern Cricket Frog
Southern Cricket Frog
Bird-voiced Treefrog
Cope’s Gray Treefrog
Green Treefrog
Barking Treefrog
Gray Treefrog
Mountain Chorus Frog
Spring Peeper Frog
Upland Chorus Frog
Eastern Narrow-mouthed Toad
Crawfish Frog
Gopher Frog
American Bullfrog
Green Frog
Pickerel Frog
Southern Leopard Frog
Wood Frog
More information about amphibians
Amphibians from Around the World
Tennessee Amphibian Monitoring Program
Amphibians
Amphibians are the class of vertebrate animals containing the Anura (frogs and toads), Urodeles or Caudata (salamanders and sirens), and the lesser known Gymnophiona (caecilians) which do not occur in North America.
Amphibians are ectothermic (cold-blooded), have smooth porous skin, primarily fertilize their eggs externally and do not have a hard shell or membrane around the eggs.
The word amphibian comes from the Greek language and means “dual life.” This refers to the lifestyle practiced by many amphibians. The adults are primarily terrestrial (land-dwelling) and the larva (tadpoles) are mainly aquatic (live in water).
Male frogs gather at the breeding pools and begin to vocalize (call) to attract females. Females arrive at the breeding sites and seek out the most attractive males. Those males with the deepest voices and the longest calls attract the most females.
Larger frogs have deeper voices and those frogs that are the largest and have the longest calls are the most fit. A male grasps a female from behind and grips her behind her front legs and hangs on until mating is completed (amplexus). During amplexus, the female expels her eggs and the male releases sperm into the water to fertilize them. This type of fertilization is called external fertilization.
The eggs are laid in jelly-like masses in groups of a few to as many as several hundred depending upon the species. The egg cells of each embryo begin to divide into more cells (egg cell cleavage) and grow to form the tadpole. The eggs hatch within a few days.
Tadpoles remain in the water a few weeks for most species, and up to 2 years for other species, before they metamorphose. Metamorphosis is the process in which a tadpole changes into a frog.
Population Information
Natural extinctions and population fluctuations are a normal part of nature. Scientists have uncovered five mass extinctions throughout the history of earth. But the accelerated rate at which many species are now declining and disappearing is very alarming to the scientific community. It is believed we are now in the sixth mass extinction event; the first ever caused by the actions of a single species, humankind. During the past couple decades, scientists have become concerned that many of our amphibian populations are declining and some species have become extinct in areas of the world that are relatively undisturbed by man. Below are but a few examples of the many declines and extinctions of the past two decades:
The golden toad (Bufo periglenes) was first discovered in the remote and pristine cloud forests of the Monteverde Preserve of Costa Rica in 1967. This toad was very unusual because it was sexually dimorphic (the sexes could easily be identified.) The last golden toad ever seen was in 1987 and they have now been declared extinct.
The northern gastric brooding frog (Rheobatrachus vitellinus) of Australia was discovered in 1984 and last seen in the wild in 1985 following the fate of the closely related gastric brooding frog (Rheobatrachus silus) that was discovered in Australia in 1973 and had disappeared by 1981. These unusual frogs brooded their young in their stomachs and were of interest to the scientific and medical community as they ceased [Chiricahua leopard frog] producing hydrochloric acid in the stomach when they were brooding young frogs.
In the United States, populations of the western toad (Bufo boreas) and Chiricahua leopard frog (Rana chiricahuensis) have plummeted by 80%, the mountain yellow-legged frog (Rana mucosa) has disappeared from much of its range, and recent surveys to find the Yosemite toad (Bufo canoris) in Yosemite National Park were fruitless. Two species, the relic leopard frog (Rana onca) and the Wyoming toad (Bufo baxteri) are on the brink of becoming extinct in the wild and the Vegas Valley leopard frog (Rana fisheri), last seen in 1942, is now extinct.
Population declines and extinctions are not the only problems facing amphibians today. Scientists have noted an increase in reports of malformations. Scientists believe there are three main factors contributing to the increase in malformations: increases in UV-B radiation because of the thinning ozone layer, chemical pollution (insecticides and pesticides), and parasites (chytrid fungus). These factors combined with a weakened immune system due to environmental stressors, can increase the number of malformations found in a population. Malformations come in many forms ranging from missing limbs, bones and eyes, to extra limbs, digits and eyes. Few, if any, of these malformed amphibians survive to reproduce. Tennessee does not appear to have an abnormal number of malformations, but we need to be watchful. For more information about malformations, including state maps showing reported malformations, visit the North American Reporting Center for Amphibian Malformations.
Amphibians, including the frogs and toads, around for over 360 million years, survived the mass extinction event that killed the dinosaurs. Below is relative time scale showing geologic history and when the amphibians first appeared.
Some Identified Causes of Amphibian Declines Around the World
Increased UV radiation due to ozone depletion (montane species which breed in open water are most at risk.)
Chemical pollution (including fertilizers, pesticides, insecticides and herbicides.)
Climate change, both temporary and long term (temporary changes include, drought and flood; long term changes include changes in wind patterns, rain patterns and especially global warming.)
Disease (chytrid fungus has been implicated in the decline of many species.)
Increased predation (cats, coyotes and some introduced species are major predators of tadpoles, frogs and other wildlife. )
Introduction of exotic species, including plants (native species often lose out when having to compete with exotic species, and native plants can use up resources, like water, that are needed by amphibians.)
Land use policies (stocking fish in amphibian habitat, installation of dams, planting of non-native plants.)
Habitat loss and degradation (including agriculture, construction, logging, urbanization and mining.)
Habitat fragmentation (division of a habitat by roadways, housing developments and other impenetrable barriers.)
TWRA: TN’s Frogs and Toads
American Bullfrog Rana catesbeiana
Photo by John White
Description: American bullfrogs are
the largest
native frogs in the U.S. They typically range from 3.5 – 6
inches long. They are green to brown in color and are characterized by a ridge curving
from behind the eye around the tympanum (the “ears”). They will eat almost any
living creature they can fit into their mouths.
Reproduction & Growth: Females
lay 1000 – 5000 eggs
in a thick surface film. Metamorphosis of tadpoles takes 1 – 2 years. The
American bullfrog requires 2 – 3 additional years to reach maturity.
Habitat: American bullfrogs live in
medium to large permanent bodies of water (lakes or ponds)
throughout Tennessee.
Voice: (WAV or AU file 73K)
Described as a deep, bass “VRUU-UUM.” (Recording courtesy of Lang
Elliott.)
Green Frog Rana clamitans
Photo by William
Flaxington
Description: Green frogs range in
size from 2 – 3.5
inches long. They are green to brown in color, and are characterized by
ridges around the tympanum and folds of skin extending down the middle of the back.
Reproduction & Growth:
Females lay 1000 – 4000 eggs
on the water’s surface. Metamorphosis of tadpoles takes 2 – 3 months.
Maturity is reached in 2 years after completion of metamorphosis.
Habitat: Green frogs live in
semi-permanent to permanent shallow bodies of water
(lakes, ponds, streams or ditches) throughout Tennessee.
Voice: (WAV or AU file 36K)
Similar to the sound of a loose banjo string. (Recording courtesy of Lang
Elliott.)
Wood Frog Rana sylvatica
Photo by Scott Egan,
University of Rhode Island Dept. of Natural Resources
Description: Wood
frogs are typically 1.25 – 3 inches long. They are brown to
pink in color and are characterized by a dark mask extending from the eye backwards across
the tympanum. Wood frogs are found as far
north as Alaska.
Reproduction & Growth:
Females lay large globular
masses of up to 3000 eggs and anchor them to submerged vegetation. Wood
frogs are communal breeders so many egg masses are often laid at one time.
Eggs hatch within 3 weeks. Metamorphosis of tadpoles takes about 2 months,
and maturity is reached in 2 – 4 years.
Habitat: Wood frogs are found in
moist woodlands in eastern to north central Tennessee.
Breeding may take place in open water ponds to roadside ditches.
Voice: (WAV or AU file 34K)
A harsh “quacking” sound. (Recording courtesy of Lang Elliott.)
Southern Leopard Frog Ranasphenocephala
Photo by Denny
Cannon
Description: Southern leopard frogs
are 2.5 – 3
inches long. They are green and brown in color with dark rounded spots on
the back, a light line on the lip, and a light spot in the center of the
tympanum. They have a long pointed snout.
Reproduction & Growth:
Females may produce 3000 –
5000 eggs laid in a globular mass and attached to stems of vegetation. Eggs
hatch in 7 – 12 days. Metamorphosis of tadpoles takes about 2 -3
months.
Habitat: Southern leopard frogs are
found in shallow permanent or semi-permanent water
from woodland ponds to roadside ditches throughout Tennessee except in the eastern high
elevations. These frogs may travel far from water if there is adequate cover.
Voice: (WAV or AU file 175K)
A series of chuckling notes followed by a grunting sound. (Recording courtesy of Lang
Elliott.)
Pickerel Frog Rana palustris
Photo by Allen
Sheldon
Description: Pickerel frogs are
typically 1. 75 – 3 inches long. They are brown,
copper or green in color and are characterized by distinctive square spots
in two rows down the back, and bright yellow to orange splotches on the
inner surfaces of the upper thighs and groin.
Reproduction & Growth:
Females lay eggs underwater in
loose globular masses attached to vegetation. Eggs take about 2 weeks to
hatch. Metamorphosis of tadpoles takes about 2 – 3 months.
Habitat: These frogs are found in
moist woods, bogs,
grassy fields near streams, and in the twilight zones of caves. They are
found throughout the state, but are more rare in the western part of
Tennessee.
Voice: (WAV or AU file 37K) A
low-pitched snore lasting 1 – 2 seconds. (Recording courtesy of Lang
Elliott.)
Gopher Frog Rana capito
Photo by Bob
English, LEAPS
Description: Gopher frogs are 2. 5 –
3.5 inches long. They are dark gray in
color with dark irregular spots on the back, and a mottled belly. They have
prominent folds of skin extending down the back.
Reproduction & Growth: The dusky
gopher frog is an
explosive breeder, all of the mature, healthy adults in a population
breeding at once. The males usually call to attract females only after heavy
rains. Females lay egg masses of up to 7000 eggs and attach them to
vegetation. Metamorphosis of tadpoles takes about 3 – 4 months.
Habitat: The dusky gopher frog is
found in wooded
areas where it spends the daylight hours underground in the burrows of other
animals. Only two individuals of this species have been found in Tennessee
in the central region.
Voice: (WAV
or AU file 74K) A
deep snore lasting 2 seconds. (Recording courtesy of Carl Gerhardt.)
Crawfish
Frog Rana areolata
Photo by Bob
English, LEAPS
Description: Crawfish frogs are
typically 2. 25 – 3 inches long. They are
dark gray in color and are characterized by dark spots outlined with a light border on the
back.
Reproduction & Growth:
Females lay masses of 3000 –
7000 eggs. Eggs are attached to stems of vegetation. Metamorphosis of
tadpoles takes about 2 months.
Habitat: Northern crawfish frogs are
normally found in lowland woods, river floodplains and
wetland prairies in western Tennessee. They remain underground in the burrows of other
animals (often crawfish burrows) during the day.
Voice: (WAV or AU file 66K) A
deep snore that sounds like “waaaaater.” (Recording courtesy of Carl
Gerhardt.)
Green Treefrog Hyla cinerea
Photo by John
Pickering, www.discoverlife.org
Description: Green treefrogs are
1. 25 – 2.25 inches
long. They are usually bright green in color with a distinct white or yellow
stripe from the mouth to the thigh. Occasionally, the back is flecked with
yellow.
Reproduction & Growth:
The eggs are laid in small
packets or films at or near the surface and attached to floating vegetation. The
eggs are brownish to black with white or cream. Metamorphosis of tadpoles
takes about 1 – 2 months.
Habitat: These frogs are found in
forested areas and swamps in western Tennessee that
have abundant vegetation surrounding the shoreline.
Voice: (WAV or AU file 57K) A
loud nasal “Queenk…Queenk.” (Recording courtesy of Lang
Elliott.)
Barking Treefrog Hyla gratiosa
Photo by John White
Description: Barking treefrogs are
typically 2 – 2. 5
inches long. They are green to brown in color with an indistinct white or
yellow stripe from the mouth to the thigh.
Reproduction & Growth: Females
deposit single eggs on
the bottom of ponds or pools. A single female may produce as many as 2000
eggs. Metamorphosis of tadpoles takes about 1 – 2 months.
Habitat: Barking treefrogs have been
found in West Tennessee, the extreme north central
part of the state, and near the Sequatchie Valley. They are found in wet woodlands,
shallow ponds, and cypress swamps.
Voice: (WAV or AU file 59K) A
harsh barking “aaark-aaark” or a hollow “oonk.” (Recording courtesy
of Lang Elliott.)
Gray Treefrog Hyla versicolor
Photo by Scott Egan,
University of Rhode Island Dept. of Natural Resources
Description: Gray treefrogs are 1.25
– 2 inches long.
Their coloration is highly variable but usually gray or green with irregular
markings on the back. They are characterized by a white spot under the eye,
warty skin, and yellow-orange on the concealed surfaces of the thigh.
Reproduction & Growth:
Females lay clusters of 10 to
30 eggs that are attached to vegetation near the surface of the water. The
eggs hatch in 3 – 6 days. Metamorphosis of tadpoles takes from 1 – 2 months
and maturity is reached in 2 years.
Habitat: They are found in varied
habitats with small trees or shrubs. They are rarely
found outside of the breeding season as they forage in the canopy. Their distribution in
Tennessee is not well known.
Voice: (WAV or AU file 110K) A
short, slow trill. (recording courtesy of Lang Elliott.)
Cope’s Gray
Treefrog Hyla chrysoscelis
Photo by Terry
Hibbitts
Description: Cope’s gray treefrogs are 1. 25 – 2
inches long. Their
coloration is highly variable but usually gray or green with irregular markings on the
back. They are characterized by a white spot under the eye, warty skin, and yellow-orange
on the concealed surfaces of the thigh.
This species is indistinguishable from the gray treefrog except by call or chromosome
analysis. The gray treefrog has 48 chromosomes, while Cope’s gray treefrog has 24.
Reproduction & Growth: Females lay clusters
of 10 – 30 eggs that
are attached to vegetation near the surface of the water. Eggs hatch in 3 –
6 days. Metamorphosis of tadpoles takes about 1 – 2 months. Sexual maturity
is reached in 2 years.
Habitat: They are found in varied habitats with
small trees or
shrubs
throughout Tennessee.
Voice: (WAV or AU file 51K) A
short, fast trill. (Recording courtesy of Carl Gerhardt.)
Bird-voiced Treefrog Hyla avivoca
Photo by Walter W.
Knapp
Description: Bird-voiced treefrogs
are 1 – 1.75 inches
long. Their coloration is highly variable but usually gray or green with
irregular markings on the back. They are characterized by a white spot under
the eye, warty skin, and yellow-green to pale green on the concealed
surfaces of the thigh.
Reproduction & Growth: Females
lay small masses of 6
– 15 eggs in shallow water. Metamorphosis of tadpoles takes about 1 month.
Habitat: They are found in western
Tennessee, in permanent backwater swamps of creeks
and large rivers.
Voice: (WAV or AU file 73K) A
series of birdlike whistles. (Recording courtesy of Carl Gerhardt.)
Spring Peeper Pseudacris crucifer
Photo by John White
Description: Spring peepers are
0. 75 – 1.25 inches
long. They are brown to gray with a dark “X” on the back.
Reproduction & Growth:
Females lay from 800 – 1000
eggs singly or in clusters of 2 – 3. Eggs are attached to submerged
vegetation and hatch in 2 – 3 days. Metamorphosis of tadpoles takes from 3 –
4 months. Sexual maturity is reached within 1 year.
Habitat: They are found in wooded
or brushy areas near temporary or semi-permanent
bodies of water throughout Tennessee.
Voice: (WAV or AU file 57K) A
high pitched, piping whistle, “peep, peep, peep.” (Recording courtesy of Lang
Elliott.)
Southeastern Chorus Frog Pseudacris feriarum
Photo by Terry
Hibbitts
Description:
Southeastern chorus frogs are 0.75 – 1.5 inches long.
Their coloration varies from pale gray to dark brown. They have a white line on the upper
lip, and a dark line extending from the snout through the eye and ending at
the groin.
Reproduction & Growth:
Females lay up to 100 eggs and
attach them to vegetation. The eggs hatch within 18 days. Metamorphosis of
tadpoles takes about 2 – 3 months. Tadpoles become mature adults within 1
year.
Habitat: They are found statewide,
in wet meadows, moist hardwood forests, or swampy
bottomlands.
Voice: (WAV
or AU file 60K) A
series of rapid clicks. (Recording courtesy of Lang Elliott.)
Mountain Chorus Frog Pseudacris brachyphona
Photo by Walter W.
Knapp
Description: Mountain chorus frogs
are 1 – 1.25
inches long. They are brown, gray, or olive with a dark triangle between the
eyes, a light line on the upper lip, yellow on the concealed surfaces of the
hind legs, and two stripes in the form of reverse parenthesis on the back.
Reproduction & Growth:
Females lay eggs in groups of
10 – 50, laying as many as 400 eggs. Egg masses are attached to vegetation
in ditches or pools. Metamorphosis of tadpoles takes about 2 months.
Habitat: They are found in the
upland woods of hills and mountains
of the Cumberland
Plateau, Cumberland Mountains, and the extreme northeast and southeast of the Blue Ridge
Mountains.
Voice:
(WAV or AU file 60K) A
series of fast, low- pitched clicks, “REEK-raaack.” (Recording courtesy of
Carl Gerhardt.)
Northern Cricket
Frog Acris crepitans
Photo by Will
Cook
Description: Northern cricket frogs
are 0.5 – 1.5 inches long. Their
coloration varies, but they all have a dark triangle between the eyes, the skin is warty,
and there is a dark ragged stripe on the thigh.
Reproduction & Growth: Females
lay clusters of 10 –
15 eggs, laying up to 200 eggs on the water surface and attach them to vegetation.
Metamorphosis of tadpoles takes from 1 – 2 months. Northern cricket frogs
become sexually mature within 1 year.
Habitat: They are found statewide,
except for the
extreme northeast, near permanent bodies of shallow water and slow moving
streams where cover is abundant.
Voice: (WAV or AU file 57K) A
series clicks that begin slowly, speed up, and slow down again. (Recording courtesy of
Lang Elliott.)
Southern Cricket Frog Acris gryllus
Photo by Walter W.
Knapp
Description: Southern cricket frogs
are 0.5 – 1.25 inches long. Their
coloration varies, but they all have a dark triangle between the eyes, the skin is warty,
and there is a dark clean-cut stripe on the thigh. The snout is pointed.
Reproduction & Growth: Females
lay around 150 eggs in
shallow ponds with vegetation. More than 1 spawning may occur in a year.
Metamorphosis of tadpoles takes 2 – 3 months.
Habitat: They are found in southwest
Tennessee, near semi-permanent bodies of water
such as temporary ponds or ditches surrounded by grasses.
Voice: (WAV or AU file 80K) A
series of clicks that remain constant in tempo. (Recording courtesy of Lang
Elliott.)
American Toad Bufo americanus
Photo by Charlie
Freeman, TWRA
Description: American toads are 2 –
3.5 inches long.
Their coloration varies from shades of gray or brown to brick red. They have some
spotting on the chest, and only 1 – 2 warts per dark spot. The cranial
crests do not lie against the parotoid glands (see Fowler’s toad. )
Reproduction & Growth:
Females lay spiral strands
of 4000 – 8000 eggs that normally hatch within 1 week. Metamorphosis of
tadpoles takes about 2 months. The toad reaches maturity in 2 – 3 years.
Habitat: They are found statewide,
from backyard gardens to upland forests. They are
active mostly at night.
Voice: (WAV
or AU file 249K) A
long, high pitched trill lasting 6-30 seconds. (Recording courtesy of Lang
Elliott.)
Fowler’s Toad Bufo fowleri
Photo by Dennis
Desmond
Description: Fowler’s toads are 2-3
inches long.
Their coloration varies from shades of gray or brown to brick red. They do not have
any spotting on the chest, and have 3 or more warts per spot. The cranial
crests butt up against the parotoid glands.
Reproduction & Growth:
Females lay strings of
7000 – 10,000 eggs attached to vegetation in shallow ponds . The tadpoles
hatch in 5 – 7 days. They are small and dark, often attach themselves to
underwater vegetation and swim in dense groups. Metamorphosis of tadpoles
takes about 30 – 40 days and maturity is reached by two years of age.
Habitat: They are found statewide,
from backyard gardens to upland forests. They are
active mostly at night.
Voice: (WAV or AU file 66K) A
nasal “WAAAAAAH” lasting 1 – 4 seconds. (Recording courtesy of Lang
Elliott.)
Eastern Spadefoot Scaphiopus holbrookii
Photo by John White
Description: Eastern spadefoots are
1.75 – 3 inches
long. They have a spade-like protuberance on each hind foot for digging.
Their coloration varies from gray to brown. A lyre shape may be formed by
two lines on the back. This is our only frog or toad with vertical pupils.
Photo by Walter W. KnappSpade
Reproduction & Growth:
Eastern spadefoots are
explosive breeders and heavy summer rains initiate breeding. The eggs are
laid in easily broken strands and attached to vegetation. Hatching occurs in
24 – 72 hours in hot weather and may take up to one week in cooler weather.
Metamorphosis of tadpoles takes less than one month.
Habitat: They are found statewide,
except in the Blue Ridge Mountains, in forested areas
with loose or sandy soil. They spend most of their time underground.
Voice: (WAV or AU file 32K) A
short, loud “BURR.” (Recording courtesy of Mississippi
Department of Wildlife, Fisheries, and Parks.)
Eastern
Narrow-mouthed Toad
Gastrophryne carolinensis
Photo by Peter
May
Description: Eastern narrow-mouthed
toads are 1 –
1. 25 inches long. They are triangular in appearance with a fold of skin just
behind the eyes. They may be gray, brown, or reddish in color with dark
markings on the back.
Reproduction & Growth:
Eastern narrow-mouthed
toads are explosive breeders and heavy summer rains trigger breeding.
Females lay 10 – 150 eggs in masses upon the surface of the water in shallow
ponds and pools. Metamorphosis of tadpoles takes 1 – 2 months.
Habitat: They are found statewide,
except in the Blue Ridge Mountains, usually under
rocks and logs or underground in burrows.
Voice: (WAV or AU file 45K) Sounds
like the bleat of a lamb, lasting 1/4 – 4 seconds. (Recording courtesy of Carl
Gerhardt.)
Many thanks to Lang Elliott of NatureSound Studio, Carl Gerhardt of the University of
Missouri, and the Mississippi Department of Wildlife, Fisheries and Parks for giving us
permission to use their recordings of frog and toad songs for this web site.
This type of fertilization is called external fertilization.
Below are but a few examples of the many declines and extinctions of the past two decades:
Two species, the relic leopard frog (Rana onca) and the Wyoming toad (Bufo baxteri) are on the brink of becoming extinct in the wild and the Vegas Valley leopard frog (Rana fisheri), last seen in 1942, is now extinct.
For more information about malformations, including state maps showing reported malformations, visit the North American Reporting Center for Amphibian Malformations.
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They will eat almost any
Wood frogs are found as far
They are green and brown in color with dark rounded spots on
75 – 3 inches long. They are brown,
5 –
25 – 3 inches long. They are
25 – 2.25 inches
5
of Natural Resources
25 – 2
75 – 1.25 inches
They have a white line on the upper
The snout is pointed.
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