10 Types of Frogs Found in Wisconsin! (ID Guide)
“What kind of frogs can you find in Wisconsin?”
I love finding, observing, and hearing frogs!
Even as a kid, I used to patrol the swamps by my house, catching them and then trying to sell them as pets to cars passing by. As you can imagine, no one was interested in buying my frogs, and I ended up letting them go at the end of each day. 🙂
Today, I’m providing a guide to teach you about the different kinds of frogs found in Wisconsin.
One of the BEST ways to find frogs is to learn the noises they make. So, in addition to pictures, you will find audio samples for each species below!
10 Frog Species in Wisconsin:
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#1. American Bullfrog
- Lithobates catesbeianus
Identifying Characteristics:
- Adult body lengths range from 3.6 to 6 inches.
- Coloration is typically olive green, with some individuals having gray or brown mottling or spots.
- Fully webbed back feet.
The American Bullfrog is the largest frog in Wisconsin!
Believe it or not, they can grow to weigh as much as 1.5 pounds (.7 kg).
American Bullfrog Range Map
Green = native range. Red = introduced range.
Bullfrogs can be found in permanent bodies of water, including swamps, ponds, and lakes. During the breeding season, the male frogs select egg sites in shallow waters, which they defend aggressively. A female will then select a male by entering his territory.
They are named for their deep call, which is thought to sound like a bull bellowing.
Bullfrogs are known to eat just about anything they can fit in their mouth and swallow! The list of prey includes other frogs, fish, turtles, small birds, bats, rodents, insects, crustaceans, and worms. I have personally witnessed one even trying to eat a baby duck!
#2. Northern Leopard Frog
- Lithobates pipiens
Identifying Characteristics:
- Adults range from 2 to 4.5 inches long.
- Smooth skin is green, brown, or yellow-green with large dark spots.
- Lighter-colored raised ridges extend down the length of the back.
You can spot Northern Leopard Frogs in Wisconsin near slow-moving bodies of water with lots of vegetation. You might see them in or near ponds, lakes, streams, and marshes. I love how bright green most individuals appear!
Northern Leopard Frog Range Map
Due to their fairly large size, these frogs eat various foods, including worms, crickets, flies, and small frogs, snakes, and birds. In one study, a bat was even observed being eaten!
During the spring breeding season, the males will float in shallow pools emitting a low call thought to sound a bit like snoring. The Northern Leopard Frog may also make a high, loud, screaming call if captured or startled.
Northern Leopard Frog populations are declining in many areas, and the cause is not exactly known. It’s thought to be some combination of habitat loss, drought, introduced fish, environmental contaminants, and disease.
#3. Green Frog
- Lithobates clamitans
Identifying Characteristics:
- Adult body lengths range from 2 to 4 inches, and the females are typically larger than males.
- Coloration is normally green or brown with darker mottling or spots on the back.
- Ridges run down the sides of the back and they have webbed hind feet.
Green Frogs are one of the easiest frogs to find in Wisconsin.
Green Frog Range Map
Look for them in permanent bodies of water, including lakes, ponds, swamps, and streams. They spend most of their time near the shoreline but jump into deeper water when approached. They also breed and lay eggs near the shore, typically in areas with aquatic vegetation.
The Green Frog produces a single note call that is relatively easy to identify. Listen for a noise that sounds like a plucked banjo string, which is often repeated.
To hunt, they use a “sit and wait” approach, so they are fairly opportunistic. Green Frogs will try to eat almost anything they can fit inside their mouth. The list includes spiders, insects, fish, crayfish, snails, slugs, small snakes, and even other frogs!
#4. Spring Peeper
- Pseudacris crucifer
Identifying Characteristics:
- Adults are small and range from 1 to 1.5 inches long.
- They’re typically tan or brown, with the females being lighter in color.
- Both males and females usually feature a darker cross or ‘X’ on their back.
These tiny frogs can be found all over Wisconsin.
You’ll typically spot Spring Peepers on the forest floor among the leaves. However, they do have large toe pads that they use for climbing trees.
Spring Peeper Range Map
You can find them in ponds and small bodies of water in the spring, where they breed and lay eggs. After hatching, the young frogs remain in the tadpole stage for about three months before leaving the water.
Spring Peepers get their name from their distinctive spring chorus. They’re thought to sound a bit like baby chickens’ peeps, and they are most often heard in early spring! LISTEN BELOW!
Their calls are very distinctive, and once you know what to listen for, these frogs are very easy to identify by sound.
#5. Gray Treefrog
- Dryophytes versicolor
Identifying Characteristics:
- Adult body lengths range from 1.5 to 2 inches.
- Mottled gray, green, and brown coloring. Look for a whitish spot beneath each eye.
- Bumpy skin, short snouts, and bright orange on the undersides of their legs.
Chameleons aren’t the only animal that can change colors! This incredible frog can slowly change colors to match what it’s sitting on to camouflage itself. They can vary from gray to green or brown. It’s common for their back to display a mottled coloring, much like lichen.
Gray Treefrogs are ubiquitous throughout Wisconsin. You’ll spot them in a wide variety of wooded habitats, from backyards to forests to swamps.
Gray Treefrog Range Map
They stick to the treetops until it’s time to breed. Gray Treefrogs prefer to mate and lay eggs in woodland ponds without fish. They’ll also use swamps and garden water features.
Gray Treefrogs are easier to hear than to see.
Listen for a high trill that lasts about 1 second, which is commonly heard in spring and summer.
*Gray Treefrogs are essentially identical to Cope’s Gray Treefrogs. The only way to tell the difference is to listen to their breeding calls. You can learn more by visiting this site.*
#6. Pickerel Frog
- Lithobates palustris
Identifying Characteristics:
- Adult body length ranges from 2 to 4 inches.
- Dark green-brown coloration with two rows of dark squarish spots running down its back. Bright yellow color on the underside of hind legs.
- Females are typically darker and larger than males.
Pickerel Frogs prefer cool, clear waters in Wisconsin. You can find them in ponds, rivers, lakes, slow-moving streams, and even ditches.
Pickerel Frog Range Map
During the breeding season, the males attract females with a low, snore-like call. The females will attach egg masses to branches in cool water, where the tadpoles will spend 87-95 days before becoming frogs.
Pickerel Frogs are the ONLY poisonous frog native to Wisconsin.
When attacked, they produce toxic skin irritations that can be fatal to other animals and may cause skin irritation in humans if handled. As you can imagine, most predators leave them alone!
#7. Wood Frog
- Lithobates sylvaticus
Identifying Characteristics:
- Adult body lengths range from 1.5 to 3.25 inches.
- Coloration is various shades of brown, gray, red, or green, with females tending to be more brightly colored.
- Distinct black marking across the eyes, which resembles a mask.
As the name suggests, Wood Frogs are found in Wisconsin in moist woodland habitats, including forested swamps, ravines, and bogs. They travel widely and visit seasonal pools to breed.
Wood Frog Range Map
This incredible little frog has a wide range across North America. They have adapted to cold climates by being able to freeze over the winter. Their breathing and heartbeat stop, and their bodies produce a type of antifreeze that prevents their cells from bursting. In the spring, they thaw and begin feeding again.
Interestingly, Wood Frogs seem to be able to recognize their family. Scientists have found that as tadpoles, siblings will seek each other out and group together!
Wood Frogs are one of the first amphibians to emerge after the snow melts.
Listen for a call that sounds a bit like a clucking chicken near vernal pools and other small bodies of water!
#8. Mink Frog
- Lithobates septentrionalis
Identifying Characteristics:
- Adult body lengths range from 1.9 to 3 inches.
- Coloration is green with darker green or brown blotches. Cream, yellow, or white underside.
- Bright green lips and webbed hind feet.
The Mink Frog gets its name from the unusual scent it produces when handled. It’s believed to smell like a mink or rotting onions!
Mink Frog Range Map
These small frogs are primarily aquatic and can be found in ponds, lakes, swamps, and streams, particularly in wooded areas. They favor areas with water lilies which they utilize for protection from predators.
During the breeding season, the males produce a rapid series of croaks thought to sound like tapping a hammer on wood.
When large numbers of Mink Frogs gather together in Wisconsin and croak in chorus, many people think it sounds like horses walking down a cobblestone street. 🙂
Interestingly, tadpoles remain in the larval stage for a year before turning into a frog!
#9. Boreal Chorus Frog
- Pseudacris maculata
Identifying Characteristics:
- Adults range from 1 to 1.5 inches long.
- Coloration is brown, olive green, or tan with three dark stripes down the back that are sometimes broken into blotches.
- Prominent black stripe on each side from nostril, through the eye, and down the sides to the groin.
- Looks very similar to the Western Chorus Frog. Boreal Chorus Frogs are distinguished by having shorter legs.
While the Boreal Chorus Frog can be common in Wisconsin, they are rarely seen. They’re small and secretive, inhabiting moist meadows and forests near wetlands.
Boreal Chorus Frog Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
These frogs breed in shallow temporary ponds and pools such as flooded fields and roadside ditches. They require waters free of fish; otherwise, most of their eggs and tadpoles would be eaten!
Males produce a loud chorus of calls at breeding sites, which are easy to identify.
The sound has been compared to someone running a finger over the teeth of a comb (“reeeek“). You’re most likely to hear the calls in the late afternoon or evening.
#10. Blanchard’s Cricket Frog
- Acris blanchardi
Identifying Characteristics:
- Adults range from 0.6 to 1.5 inches long.
- Warty skin is typically tan, brown, olive green, or gray with darker banding on the legs.
- Dark triangular mark between the eyes on the head.
Blanchard’s Cricket Frogs can be found in or near permanent bodies of water in Wisconsin, including bogs, lakes, ponds, marshes, and slow-moving rivers and streams. They can also sometimes be spotted in temporary bodies of water such as flooded fields and drainage ditches as long as there is a permanent water source nearby.
Blanchard’s Cricket Frog Range Map
Interestingly, although they are in the “treefrog” family, they spend most of their time on the ground and in the water.
Unfortunately, Blanchard’s Cricket Frogs are declining in parts of their range and are considered threatened. They face habitat loss, chemical contamination, and competition for resources. Another pressure they face is their short life span, as the average individual only lives one year.
Males make unique, repetitive, metallic breeding calls.
The calls are thought to sound like two pebbles or marbles being clicked together. The females lay small clusters or even single eggs, and the tadpoles emerge in late summer.
Do you need additional help identifying frogs?
Try this field guide!
Which of these frogs have you seen in Wisconsin?
Leave a comment below!
