Frog taxonomy changes and therefore a discussion of the types of frogs in the United States will change over time.
In formal terms, currently the types of frogs in the United States divides into ten families and over one hundred species:
- True Toads: Twenty two species
- Burrowing Toads: One species in South Texas
- Narrow-mouthed Toads: Four species
- North American Spadefoots: Seven species
- True Frogs: Thirty species
- Flesh-bellied Frogs: One species
- Free-toed Frogs: Three species
- Treefrogs: Thirty three species
- Tail-wagging Frogs: Two species
- Neotropical Thin-toed Frogs: One species in South Texas
Given the list, it’s still fairly safe to say in an informal manner that the types of frogs in the United States divide into three major groups, true frogs, tree frogs and toads.
True Frogs
The American Bullfrog pictured at the top of the page is no doubt the picture of American true fogs. It’s the biggest frog in the United States (growing up to nine inches).
Counting the bullfrog, about thirty true frog species have been documents in the United States. They make their homes in ponds, streams and other slow moving water bodies.
Red-legged frogs, in the picture, provide a good example of an east-west frog division. Two species live in slow moving water areas of the west.
Once abundant throughout the state, the California Red-legged frog population decreased over 90% and was listed as an endangered species list in 1996. The remaining population now survives primarily along California’s coastal areas, where they still compete for territory with California’s coastal loving human population.
Northern Red-legged frogs (Rana aurora) inhabit coastal and inland areas of the Pacific Northwest from northern California to British Columbia. They prefer slow moving or still, shallow water habitats for breeding. During non-breeding season their range extends to many of the nearby forest floors.
The types of frogs called true frogs, were limited to a group of water frogs that shared similar DNA characteristics in the northern hemisphere.
Many of the American frogs were then moved to the Lithobates genus. Older texts will often still have the Rana description in the formal Latin name for the frogs. Nine of the twenty two species are Leopard Frogs.
The Chiricahua Leopard Frog comes from Arizona.
Most Leopard frogs are medium size, between two to four inches. They can often be found near canals and ponds. In states that have overlapping species identification can be a challenge.
New Jersey, for example, recently discovered they had three different species, the Northern, Southern and Atlantic Coast Leopard Frog. The Atlantic Coast Leopard Frog was officially “discovered” as a new species in 2014 based primarily on the call of the male.
Green or Bronze Frogs are usually dark green or bronze in color depending on the environment. They are medium sized frogs found in most areas of the Eastern United States. The presence of skin folds behind the eyes and down the body are the best field identification clues.
Carpenter Frogs are small frogs found along the coastal areas of the Southeast. The presence of light lines going down the back are the best field identification clues.
Crawfish frogs are medium sized frogs that inhabit areas along the Mississippi River Valley and the Gulf Coast, where ever one of their food sources, crawfish, live.
As the picture highlights, they have a light colored body that is heavily spotted. Add in some skin folds and that translates into easy identification.
Pickerel Frogs might initially be mistaken for Leopard Frogs. The presences of two rows of spots between the dorsal folds is the best field identification clue.
Except for portions of the extreme Southeast and Florida, they are common in the Eastern part of the United States.
Wood Frogs are small and hardy frogs that live in the Northern Boreal Forests. You could call them the raccoons of the frog forest because the black mask on the eyes is the best frog identification clue.
River Frogs can grow up to five inches, making them one of the largest frogs in the Southeast.
They live next to rivers and streams. Location, size and the spots or blotches on the sides are the best identification guides.
The true frogs or Rana species in the United States are mostly limited to Western species. The color of the legs is also a prime field identification clue.
For example, three of the eight Rana species are yellow-legged frogs. As the picture of the Mountain Yellow-legged frog highlights, the yellow coloration on the underside of the leg is the principle field identification clue.
All three species are California frogs, although the Foothills species overlaps into southern Oregon.
Two of the Rana Species are Red-legged frogs. And again, both are West Coast Species. The Northern Red-legged frog lives in the coastal plain from Northern California to British Columbia. The California Red-legged frog picks up its range where the other leaves off. From below Northern California down the coastal areas of the state.
The picture highlights the rod coloration on the underside of the legs.
Columbia Spotted Frogs and Oregon Spotted Frogs and Pacific Northwest species. The presence of spots all over the body suggest a Leopard Frog. However they are a distinct Rana species with a stripe on the lip.
Types of Frogs: Tree Frogs
Three types of frogs in the tree frog category are also present in the United States. Most of the species are either true tree frogs or chorus frogs.
Three species of cricket frogs also are documented in the United States. They are fairly common East of the Rocky Mountains and are best identified by the more warty skin.
Ten treefrog species in the Genus Hyla, or Holarctic tree frogs inhabit the United States.
The top picture shows an Arizona Treefrog. It’s a mountain species of both Arizona and New Mexico, explaining the other common name, Wright’s Mountain Tree Frog.
They grow to about two inches in length and are recognized as the official amphibian of Arizona.
The Canyon Tree frog, the other western species, inhabits the rivers and stream banks of rocky areas in the desert Southwest. Their diet consists of the aquatic and terrestrial insects in their territory.
They are probably the most common amphibians found in the Grand Canyon. In Arizona they are also present in the canyons of Tucson.
Pine Barrens Treefrog have nice looking and somewhat bold purple stripes on the eyes.
They are a coastal species that inhabit the pine areas of Mid-Atlantic states from New Jersey south to South Carolina.
Pine Woods Treefrog identification starts by looking for a row of spots on the thigh. The sporadic chattering call of the pine woods treefrog gives it the nickname “Morse-code frog.” It can be heard from April to October.
Two Gray Treefrog species are common in the East. The Cope’s Gray Treefrog inhabits most areas of the east from north to south.
They vary in color from mottled gray to light green but their color can change depending on environment and activity. There is usually a light spot beneath eye and the inner thigh is bright yellow or orange when exposed.
With the exception of the Southeast, Gray Treefrogs do have gray skin. However, individuals of the species can also be found with green skin.
So, any gray treefrog found in the Southeast is a Gray Treefrog, because there are no Cope’s Gray Treefrogs in the area. In all other areas, both species can be found. Only their mating calls differentiate them.
Ranked as one of the most common, and arguably nicest looking of the Hyla tree frogs, American Green Treefrogs have light green bodies with a yellow strip running along the side. There’s no mistaking their identity.
Adaptability is a key element of their commonality. They adapt well to human environments and live in water areas along the Southeast, Gulf Coast and southern areas of the Mississippi River Valley. Look for them in the garden or on the porch during late spring through early fall.
If you are a person that loses sleep over a neighborhood dog that barks all night long, wait until the Barking Treefrog.
They are primarily a coastal bunch and inhabit the coastal regions of the Southeast and Gulf Coast. The presence of dark spots on the body is often a good field identification clue given the fact that their body color can change.
Bird-voiced Treefrog. The bird-voiced treefrog is usually a mottled gray color, but like many treefrogs, its color changes from brown to green depending on temperature and environment.
They can look very similar to Gray Treefrogs. It almost goes without saying that hearing their call, a chorus of birds, is the best way to know they are in the neighborhood. Look for them in wooded swamplands of the South, where they can be heard calling during spring and summer.
Residents along the coastal Southeast are very familiar with Squirrel Treefrogs, though they might not know it. They show up in backyards and gardens everywhere. The problem is that both their skin color and pattern change, making identification difficult.
For example, their skink color can range from green to brown. There might or might not be spots on the skin. Finally some might have light stripes on the sides. During any one season, the average gardener might think they have four different treefrog species in the year because four individuals look different.
Identifying types of treefrogs boils down to learning about local species and then using them as a base line for comparison. For example, in areas of the south species such as the Gray Treefrogs will have yellow spots on the thighs.
As a matter of introduction, any group of frogs croaking together gets the common name chorus frogs. The more formal group of chorus frogs belong to the treefrog family Hylidae and the genera Pseudacris.
The Society for the Study of Amphibians and Reptiles released a 2017 circular that currently documents eighteen species of chorus frogs in the United States. Boy oh boy can they sing up a storm as they males gather in common wetlands areas during the breeding season.
The large number of species also indicates regionalism. For example, the New Jersey Chorus Frog, not presented here, has a range limited to Southeastern Pennsylvania, New Jersey, and the Delmarva Peninsula of eastern Maryland, Delaware, and Virginia.
Many types of these frogs live in all areas of the United States. Of special note, each of the species also has a distinct song, and knowing the song is also a great way to get to know the neighborhood chorus frogs.
Some species such as Spring Peepers are easy to identify. X marks the identification for Spring Peepers. They are one of the more common chorus frog species with a range that extends across most of the Midwest and East.
Three cheers for the Little Grass Frog, officially the smallest frog in the United States. It’s about one-half inch in length and has a dark stripe from the nose down the side of the body. It ranges from coastal areas of Virginia south to Florida.
Boreal Chorus Frogs inhabit the forest areas in the Upper Midwest to the forest areas of norther New Mexico and Arizona.
The Illinois Chorus Frog is a nice looking gray or dark bodied spotted species with a range along the sandy shores of the Illinoi River and Mississippi River. Habitat destruction has led to calls for them to be placed on the Endangered Species list.
Ornate Chorus Frogs, can be initially identified by the small round toe tips.
They rank among the most colorful of the frogs in our region and come in gray, green, and reddish-brown color phases. Look for the black mask-like stripe across their eye.
This species can also have yellow on the groin along with small yellow spots on the insides of their legs.
Upland Chorus Frogs also show a a stripe across the eye. They are fairly common with a range from Pennsylvania down the Appalachian Mountains and in areas of the Midwest and Texas.
The Western Chorus Frog might have a bit misleading name. It’s range extends around the great Lakes and a bit south. Look for three stripes down the back as a good identification clue.
The Pacific Tree Frog lives in ponds and other small watering holes throughout the Pacific Northwest. Sometimes called the Pacific Chorus Frog, they can really croak up a symphony of sound during the night hours.
Much like the chameleon, Pacific Tree Frogs adopt a variety of colors depending on environmental factors such as background light. It’s not unusual to see their skin change from green to brown to rust, and any combination, in a matter of hours.
Change in color need not make this frog identification task difficult. They tend to be the only tree frog in their territory. In 2007, Washington State designated the Pacific chorus frog its official state amphibian.
The Sierran Treefrog or Sierran Chorus Frog, another common western species, inhabits mountains, fields and forest in most areas of the west from Idaho to Central California. In the Washington and Western Oregon Pacific Northwest, it is replaced by the Pacific Chorus frog.
Like most species, physical characteristics are not much help in identification because individuals tend to be chameleon like and adapt their skin color to match their environment.
Here’s a list rounding out the remainder of the Chorus Frogs in the United States. Like the ones already mentioned the frog identification task begins by noting their small size and loud voices.
- Mountain Chorus Frog
- Brimley’s Chorus Frog
- Spotted Chorus Frog
- Baja California Treefrog
- New Jersey Chorus Frog
- Southern Chorus Frog
- Strecker’s Chorus Frog
- Cajun Chorus Frog
Toads
Narrow-mouthed Toads, Spadefoots and True Toads constitute to native toad group. As a starting point, all toads are frogs.
Compare the less warty body of the Eastern Spadefoot Toads. It’s the only spadefoot species that lives east of the Mississippi river, and it follows the general identification rule of thumb for spadefoot toads having relatively smoother skin.
Consider the picture of the American Toad. When people think of a toad representative species they often think this toad. It’s a small species that inhabits many areas bordering the Mississippi River to the East Coast. It’s everything you’d expect in a toad including the dull color, warty skin with a stripe on the back. They are common in many back yards with a nearby water source.
Taking the general toad identification guidelines into consideration produces some immediate problems. First, if all toads have bodies that can change color depending on the environment, how is it possible to tell one toad species from another in areas with more than one species?
For example, the next picture shows a Fowler’s Toad. Like the American Toad it grows to about two to three inches in length, has dry, warty skin and a stripe on the back.
Fowlers Toads are also found throughout much of the eastern US, often in forests with nearby water sources.
The only physical difference might be, as highlighted in the picture, the presence of more warts within the dark spots on the back. The only environmental difference is habitat. So, it’s usually a good identification guess for Fowler’s in the forest and American toad in the back yard. The identification emphasis is on good, not perfect.
Size also helps with toad identification. Oak toads win the prize of smallest toads, growing no more than an inch and one-half. Oak toads, unlike most toad species, are usually active during the day. They can be found in southern pine forests by turning over logs and other woodland debris.
Like the Fowler’s and American toad, they grow to about three inches in length. The skin is usually brown and the chest is spotted.
Fowler’s usually don’t have a coastal presence and Southern Toads do, so in coastal areas along the Atlantic and Gulf of Mexico, it’s always a good guess to start with a Southern Toad identification.
When it comes to size as an identification tool, The Gulf Coast Toad stands as the easiest of the Southeast toads to identify. It grows up to five inches in length.
Size also helps with toad identification as one moves from Eastern to Midwestern species. Consider the Great Plains toad. It grow to a bit over four and one-half inches in length. The picture also shows a toad with dark splotches on the skin. In areas where it overlaps with American Toad territory, it’s fairly easy to distinguish between the species.
Moving to the Rocky Mountains and the West Coast, think size again. The Western or Boreal Toad can grow up to five inches, ranking them as one of the largest of the native toads. Of course the non-native Cane toads can grow up to eight inches, making them the largest toads in the United States.