Frogs in Wisconsin: identification guide and where to start looking

What frogs are found in Wisconsin?

Wisconsin hosts roughly 12 native frog species, plus a few toads. The most widespread include the American toad, gray tree frog, spring peeper, green frog, northern leopard frog, and bullfrog. The rare pickerel frog and Blanchard's cricket frog occur in scattered populations. The state also has the boreal chorus frog in northern counties and Cope's gray tree frog, which overlaps with the common gray tree frog. Start with the species you are most likely to hear: spring peepers and chorus frogs call early in spring, while green frogs and bullfrogs dominate summer choruses.

How can you identify Wisconsin's tree frogs?

Wisconsin has five tree frog species: gray tree frog, Cope's gray tree frog, spring peeper, boreal chorus frog, and the rarely seen western chorus frog (often considered a subspecies). The gray tree frog and Cope's are nearly identical in the field; both can change color from green to gray to brown, but the best field mark is the bright yellow-orange flash on the inner thigh. Spring peepers are tiny (under 1.5 inches) with a dark X-shaped mark on their back. Boreal chorus frogs are slightly larger with three dark stripes down the back and a white upper lip. For a deeper look at frog identification, check out ourfrog species overview.

Where in Wisconsin should you look for frogs?

The best frog habitat in Wisconsin is along the southern half of the state, especially in the driftless area and the Lake Michigan shoreline. Top spots include the Horicon Marsh, the Wisconsin River floodplains, and the many kettle ponds in Kettle Moraine State Forest. In the north, look for frogs in Voyageurs National Park and the extensive wetlands of the Chequamegon-Nicolet National Forest. The most reliable early-season chorus comes from ephemeral ponds in hardwood forests. For a state-wide breakdown of wildlife viewing areas, see ourWisconsin wildlife page.

See ourstate animal guidefor the next step.

When is the best season for frog watching in Wisconsin?

Late March through early May is peak frog watching for spring-breeding species. By April, you can hear spring peepers, chorus frogs, and wood frogs calling from shallow wetlands. Summer breeders like green frogs and bullfrogs call from June to August. The best time of day is after sunset from 8 p.m. to midnight. Weather matters: warm (above 50°F), damp evenings with light rain trigger the most activity. Winter is quiet; only the wood frog's freeze tolerance keeps it alive under leaf litter. For timing your trip, plan around the first warm rain of spring.

What are the key field marks for Wisconsin frogs?

Start with dorsal folds: green frogs and bullfrogs have prominent ridges running down their back; leopard frogs and pickerel frogs have interrupted or spotted folds. Check toe pads: tree frogs have large, sticky pads; true frogs (Ranidae) have smaller pads or none. Look at the belly: leopard frogs have white bellies, pickerel frogs have bright yellow-orange on the inner thighs. The eye color and eardrum (tympanum) size also help separate green frogs (tympanum larger than eye) from bullfrogs (tympanum about same size as eye). For visual aids, browse ourfrog prints and artthat show detailed illustrations.

How do you tell apart similar-looking species like green frogs and bullfrogs?

The green frog and bullfrog look alike but differ in size and ridge pattern. Green frogs reach about 4 inches, bullfrogs can exceed 6 inches. Green frogs have two continuous dorsolateral folds; bullfrogs lack prominent folds. Their calls also differ: the green frog makes a single plunk like a banjo string, while the bullfrog moans an echoing jug-o-rum. Another tricky pair: the northern leopard frog and pickerel frog. Leopard frogs have irregular spots and a white belly; pickerel frogs have squarish spots in two rows and a yellow wash on the inner thighs. Pickerel frogs also secrete a skin toxin that can irritate small wounds.

Want to remember your frog sightings? Check out these prints

After a successful outing, bring the memory home with a detailed frog illustration. These prints highlight the species you might see in Wisconsin.

### Red Eyed Tree Frog Limited-Edition Print

Though not native to Wisconsin, this iconic species makes a striking display piece for any frog fan. The print captures its vivid red eyes and green body in crisp detail.Check Price and Availability

### Pine Barrens Tree Frog Limited-Edition Print

A close relative of Wisconsin's gray tree frog, this species shows similar toe pads and coloration. Great for comparing eastern tree frogs side by side.Check Price and Availability

### Wall art print: Frog by Eimear Maguire

This whimsical illustration works well as a framed piece in a study or kids' room. It pairs nicely with other wildlife art from ourwildlife shirt collection.Check Price and Availability

### iCanvas Frog Green Wall Art by Jo Lynch

A bold, colorful close-up that highlights the amphibian's texture and eye. It arrives ready to hang on your wall.Check Price and Availability

Frequently asked questions about Wisconsin frogs

**What is the most common frog in Wisconsin?** The green frog is likely the most frequently seen frog statewide, followed by the gray tree frog and northern leopard frog. Spring peepers are the most heard.

**Are there poisonous frogs in Wisconsin?** No, but the pickerel frog secretes a mild toxin that can irritate skin and is harmful to small predators. It is not dangerous to humans unless ingested.

**When do frogs start calling in Wisconsin?** The first calls come from wood frogs and spring peepers as early as late March in southern Wisconsin, with full choruses by mid-April.

**Where can I hear frog choruses near Milwaukee?** Try the Milwaukee County Zoo's frog exhibit, or visit the Schlitz Audubon Center and the ponds in Havenwoods State Forest.

**What is the difference between a frog and a toad?** Frogs have smooth, moist skin and long legs for jumping; toads have warty, dry skin and shorter legs. In Wisconsin, the American toad is the only widespread true toad.

See ourtour planning ideasfor the next step.