18 COMMON Amphibians in Illinois (ID Guide)
Are you wondering what amphibians you can find in Illinois?
This is a great question! Although amphibians are widespread, they can be challenging to locate. Most amphibians, including frogs, toads, and salamanders, are secretive and shy. But in my opinion, looking for amphibians is a really fun experience!
Below you will find a list of the most COMMON and interesting amphibians that live in Illinois. In addition, you will find detailed pictures, along with range maps for each species to help with your identification!
- RELATED: 21 Common Reptiles in Illinois (W/Pics!)
18 Types of Amphibians That Live in Illinois:
#1. American Bullfrog
- Lithobates catesbeianus
- Adult body lengths range from 3.6 to 6 inches.
- Coloration is typically olive green, with some individuals having gray or brown spots.
- Fully webbed back feet.
The American Bullfrog is one of the largest amphibians in Illinois!
Believe it or not, they can grow to weigh as much as 1.5 pounds (.7 kg). Bullfrogs can be found in permanent bodies of water, including swamps, ponds, and lakes.
American Bullfrog Range Map
Green: native range. Red: introduced range.
Bullfrogs 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!
- RELATED: The COMPLETE List of Frogs in Illinois (14 Species)
They are named for their deep call, which is thought to sound like a bull bellowing.
#2. Northern Leopard Frog
- Lithobates pipiens
- 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 these amphibians in Illinois near slow-moving bodies of water with lots of vegetation. Northern Leopard Frogs are easy to see 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 amphibians eat various foods, including worms, crickets, flies, 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 like snoring. However, 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 a combination of habitat loss, drought, introduced fish, environmental contaminants, and disease.
#3. Green Frog
- Lithobates clamitans
- 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 among the easiest amphibians to find in Illinois.
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, often repeated.
They use a “sit and wait” approach to hunt, 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
- Adults are small and range from 1 to 1.5 inches long.
- They’re typically tan or brown, with the females lighter in color.
- Both males and females usually feature a darker cross or ‘X’ on their back.
These tiny amphibians are found across Illinois.
You’ll typically spot Spring Peepers on the forest floor among the leaves. However, they 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, where they breed and lay eggs in the spring. 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 like baby chickens’ peeps, and they are most often heard in early spring! LISTEN BELOW!
#5. Gray Treefrog
- Dryophytes versicolor
- 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.
- *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.*
Chameleons aren’t the only animal that can change colors! This incredible amphibian can slowly change colors to camouflage itself and match what it’s sitting on. 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 their range. You’ll spot them in various wooded habitats, from backyards to forests to swamps. Like most amphibians in Illinois, they tend to live close to a water source.
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, commonly heard in spring and summer.
#6. Pickerel Frog
- Lithobates palustris
- Adult body length ranges from 2 to 4 inches.
- Dark green-brown coloration with two rows of dark squarish spots running down its back. The underside of the hind legs is a bright yellow.
- Females are typically darker and larger than males.
Like many amphibians in Illinois, Pickerel Frogs prefer cool, clear water. You can find them in ponds, rivers, lakes, slow-moving streams, and ditches.
Pickerel Frog Range Map
Pickerel Frogs are one of the few poisonous amphibians in Illinois!
When attacked, they produce toxic skin irritations that can be fatal to other animals and may cause skin irritation in humans if handled. So, as you can imagine, most predators leave them alone!
During the breeding season, the males attract females with a low, snore-like call. Then, the females will attach egg masses to branches in cool water, where the tadpoles will spend 87-95 days before becoming frogs.
#7. Western Chorus Frog
- Pseudacris triseriata
- Adult body length up to 1.6 inches long.
- Smooth skin with color that varies from gray to green or brown.
- Dark brown or gray stripes run down the back, a dark stripe from the snout through the eye, and a white stripe on the upper lip.
- Also called the Midland Chorus Frog.
In Illinois, look for these amphibians in woodland ponds, marshes, swamps, meadows, and grassy pools.
Western Chorus Frog Range Map
For breeding, they try to find bodies of water without fish, including flooded fields, beaver ponds, roadside ditches, marshes, and shallow lakes and ponds. The female attaches small masses of eggs to underwater vegetation.
Western Chorus Frogs are secretive and nocturnal, so they can be hard to spot. Your best way to locate one is to use your ears. Listen for a unique call that is rapid and relatively short and sounds a bit like running your finger over the teeth of a comb. PRESS PLAY BELOW.
#8. American Green Treefrog
- Dryophytes cinereus
- Adults can grow up to 2.5 inches long and have smooth skin.
- Yellowish-green to lime green with pale yellow or white undersides.
- White stripes down their sides sometimes have black borders.
Even though they are common in their range, these arboreal amphibians can be hard to find in southern Illinois since they spend most of their lives high in trees. They also can change color based on light and temperature.
American Green Treefrog Range Map
American Green Treefrogs are often kept as pets. They are popular because of their attractive appearance, size, and how easy it is to take care of them. For example, they don’t require artificial heating like most amphibians. But being nocturnal, it’s unlikely you will see them moving around much, so they are probably not the most exciting pets!
Their breeding call is a repeated, abrupt, nasal “bark” that’s incredibly easy to identify. Therefore, sound is typically the best way to locate these amphibians.
#9. American Toad
- Anaxyrus americanus
- Adult length is 2-3 ½ inches.
- Coloring is usually brown to gray, olive, or brick red. Typically, they have patches of yellow, buff, or other light colors, with dark spots.
- The American Toad is distinctive for its many warts present over the back and legs.
These amphibians are common in Illinois.
American Toads are found in a wide variety of habitats, including forests, prairies, and suburban backyards. They are carnivorous and mainly eat insects, worms, spiders, and slugs.
American Toads have a very recognizable call. Listen for a musical trilling noise that can last for 30 seconds.
They like to breed in shallow water, and tadpoles have an amazing defense against predators. Incredibly, their skin secretes a toxic chemical so powerful that eating one tadpole can kill a fish! And like their tadpoles, adult American Toads are also toxic to other animals.
#10. Fowler’s Toad
- Anaxyrus fowleri
- Adult length is 2-3 inches.
- Coloring ranges from gray to brownish green or olive, with dark splotches on the back with three or more warts. Adults have a pale stripe down their backs.
- The belly is usually white or yellowish, sometimes with dark spots breaking into smaller flecks.
Fowler’s Toads live in a wide range of habitats, including forests, river valleys, farms, and urban and suburban gardens. Like many other amphibians in Illinois, they eat various insects and are very good at pest control!
Fowler’s Toad Range Map
The mating call of the Fowler’s Toad only lasts about 1-4 seconds. Listen for a nasal “wa-a-a-ah” sound, similar to the call of a Canada Goose.
Interestingly, the Fowler’s Toad mating call attracts both males and females.
The male occasionally tries to mate with another male, only realizing his mistake when he hears the other toad’s warning chirp.
#11. Eastern Spadefoot
- Scaphiopus holbrookii
- Adult length is 1 ¾ – 2 ¼ inches.
- The coloring is brown to almost black, with two yellowish lines running down the back from the eyes.
- Spade is sickle-shaped and three times as long as it is wide.
Although they’re related to toads, spadefoots are a separate class of amphibians. Their name refers to a specialized “spade” on their leg that helps them burrow underground!
Eastern Spadefoot Range Map:
It’s rare to spot these amphibians in southern Illinois because they spend so much time underground. In fact, they can go years without a breeding season, preferring to come out only after a period of extended rain and breed explosively for a short time.
Male Eastern Spadefoots call to attract females with a short grunting noise during the breeding season. Interestingly, males float in bodies of water while they call, instead of waiting on land and following a female into the water.
#12. Eastern Newt
- Notophthalmus viridescens
- Larvae are aquatic and have smooth, olive green skin, narrow, fin-like tails, and feathery gills.
- Juveniles are terrestrial and have rough, orangish-red skin with darker spots outlined in black.
- Adults have slimy, dull olive-green skin, dull yellow undersides, darker black-rimmed spots, and a blade-like tail.
Eastern Newts have the most complicated life cycle of any amphibian in Illinois!
When they’re first hatched, they spend all of their time in the water. This larval stage lasts for two to five months. After that, they metamorphose into juvenile Eastern Newts.
They live in terrestrial forest habitats for two to seven years during their juvenile stage. Even though they generally remain hidden under moist leaf litter and debris, you may see them moving about on rainy days and nights, foraging insects, worms, and spiders. This is the stage of life you’re most likely to see an Eastern Newt. If you spot one, be careful – they have glands that secrete a potent neurotoxin when they’re threatened.
- RELATED: The COMPLETE List of Salamanders in Illinois (15 Species)
Finally, Eastern Newts will migrate back to a water source and metamorphose into aquatic adults, where they eat small amphibians, fish, and worms. They can live up to 15 years and spend the rest of their lives in this aquatic form.
#13. Spotted Salamander
- Ambystoma maculatum
- Adults are 5.9 to 9.8 inches long with wide snouts. They are typically black but may also be bluish-black, dark grey, dark green, or dark brown.
- They have two uneven rows of spots down their back, from just behind their eyes to the tip of their tail. Spots on the head are orange and fade to yellow further down the body and tail.
The Spotted Salamander is found primarily in hardwood forests with vernal pools, temporary ponds created by spring rain. Like many small amphibians in Illinois, they require vernal pools for breeding because the fish in permanent lakes and ponds would eat all their eggs and larvae.
These amphibians are fossorial, meaning they spend most of their time underground. Spotted Salamanders are typically only seen above ground just after heavy rain, so you’ll need to get a little muddy to find one! They go dormant underground during the winter months and don’t come out until the breeding season between March and May.
#14. Eastern Tiger Salamander
- Ambystoma tigrinum
- Adults range from 6 to 8 inches in length.
- Their coloring is dark gray, brown, or black with brownish-yellow to greenish-yellow markings, ranging from large spots and stripes to small irregular shapes on the head, back, and tail.
- This species has a thick body and neck, short snout, strong legs, and a lengthy tail.
These amphibians are one of the largest salamanders in Illinois.
Eastern Tiger Salamanders are secretive and spend much of their time underground in woods, grasslands, or marshes. You’re most likely to see them moving about and foraging on rainy nights.
Their diet is primarily made up of insects, worms, slugs, and frogs. However, if there’s a prey shortage, they become much less picky. They’ve been observed feeding on baby snakes, newborn mice, and small salamanders of other species. They will even cannibalize their own young in times of low food supply!
Although Eastern and Western Tiger Salamanders are closely related, it would be unusual to mix up these two species. First, they rarely share the same range and aren’t often seen together. Secondly, Eastern Tiger Salamanders are much larger and have a black patch on their snout.
#15. Common Mudpuppy
- Necturus maculosus
- Adults range from 8 to 19 inches in length.
- This species is rusty brown to gray or black with scattered bluish-black or black spots.
- The large, bushy, red, or maroon external gills behind the flattened head make this species easy to identify.
Common Mudpuppies are among the most well-known amphibians in Illinois.
These LARGE salamanders can be found in nearly any body of water, including lakes, reservoirs, ditches, and rivers. They are secretive and require habitats with lots of cover, such as boulder piles, submerged logs, tree roots, or vegetation.
Common Mudpuppies are nocturnal and spend their days hiding under rocks. They’re active at night and hunt by walking along the lake or river bottom, but they can also swim. These opportunistic feeders eat whatever aquatic organisms they can catch, including insect larvae, small fish, fish eggs, aquatic worms, snails, and even carrion.
In the spring, when water temperatures don’t fluctuate as much, these amphibians spend time in shallow water. However, they have been reported in water as deep as 100 feet during the summer and winter!
#16. Red-backed Salamander
- Plethodon cinereus
- Adults range from 2 to 5 inches in length.
- Adults can occur in two color phases: the “lead-back” is consistent gray or black, and the “red-back” has an orange to red stripe down the back and tail.
Unlike most other amphibians in eastern Illinois, Red-Backed Salamanders don’t have lungs OR gills! Instead, they “breathe” with their thin skin, absorbing oxygen through moisture. This unique trait means they must stay moist to survive.
Red-backed Salamanders are typically found beneath leaf litter, logs, bark, rocks, or burrows in deciduous forests. They have a low tolerance for dry weather, and typically you’ll only see them during or after rainfall. In the winter, they hibernate underground.
The different phases are also believed to have different methods of predator evasion. For example, the “lead-back” phase salamanders tend to run from predators, while the “red-back” phase will freeze. Both phases of the Red-backed Salamander may also drop all or part of their tail to escape a predator. Eventually, the tail will grow back but is usually duller in color.
#17. Four-Toed Salamander
- Hemidactylium scutatum
- Adults grow up to 3.9 inches in length.
- Orangish-brown to reddish-brown coloring with a brighter tail, grayish flanks, and white underside with small black spots.
- They have an elongated body and limbs, short snout, prominent eyes, and four toes on their hind feet.
Adult Four-Toed Salamanders are typically found in hardwood forests near bogs, floodplains, or swamps. They’re almost always found near sphagnum moss, and you’ll want to look under the leaf litter, logs, rocks, or other debris to find them.
As adults, these amphibians primarily feed on small invertebrates such as spiders, worms, and insects. Predators like larger salamanders, snakes, and birds of prey will hunt Four-Toed Salamanders while they forage. If threatened, they may play dead or drop their tails, giving them a chance to escape predators.
These amphibians are relatively uncommon in Illinois due to their specialized habitat. So if you see one in the wild, consider yourself lucky!
#18. Marbled Salamander
- Ambystoma opacum
- Adults range from 3.5 to 4.25 inches in length.
- Their coloring is dark brown or black. Males have white crossbands while females have silver or gray.
- Stout-bodied and chubby, females tend to be larger than males.
Marbled Salamanders occupy various damp habitats, from low-lying floodplains to moist, wooded hillsides. However, they spend most of their time underground or beneath rocks, logs, leaf litter, or other debris, so it’s unusual to find one unless you’ve disturbed its hiding place!
These amphibians are considered a keystone species in Illinois, an animal whose disappearance would completely change its ecosystem.
For example, let’s look at the relationship between Marbled and Spotted Salamanders:
Marbled Salamanders eat Spotted Salamander larvae, which eat zooplankton. Therefore, if Marbled Salamanders were suddenly removed from this food chain, the Spotted Salamander population would explode.
With so many more Spotted Salamanders eating zooplankton, eventually, the zooplankton would become extinct in that area. Then, once their food source disappeared, Spotted Salamanders would also disappear.
What types of amphibians in Illinois have you seen?
Let us know in the comments!