The sound of a banjo-like call from a Michigan swamp at dusk almost certainly comes from a green frog rather than a bullfrog. This Michigan frog identification guide will help you tell them apart, along with every other frog species in the state.
Michigan is home to about 13 species of frogs and toads. Some are common, some are rare. Knowing which one you’re looking at can be tricky, but it’s not impossible.
This guide covers size, color, calls, and habitat. You’ll learn to identify each species quickly. No fluff, just practical steps.
Michigan Frog Identification Guide
Frogs in Michigan fall into two main groups: true frogs and treefrogs. Toads are a separate group. Each has unique features.
Start by looking at the skin. Frogs have smooth, moist skin. Toads have dry, warty skin. This is the easiest first step.
Next, check the size. Bullfrogs are huge. Spring peepers are tiny. Size alone can narrow down the options.
Finally, listen to the call. Each species has a distinct sound. A recording app can help, but your ears work fine.
True Frogs In Michigan
True frogs have long legs, smooth skin, and live near water. They include bullfrogs, green frogs, and leopard frogs.
American Bullfrog
This is the biggest frog in Michigan. Adults can reach 8 inches long. They are green or brown with no distinct spots. The call is a deep, low “jug-o-rum.”
- Size: 3.5 to 8 inches
- Color: Green to brown, no spots
- Habitat: Permanent ponds, lakes
- Call: Deep, resonant “jug-o-rum”
Green Frog
Green frogs look like small bullfrogs. They have two ridges (dorsolateral folds) down their back. The call is a single, banjo-like “twang.”
- Size: 2.25 to 4 inches
- Color: Green or brown, with ridges
- Habitat: Marshes, streams, ponds
- Call: Single “twang” sound
Northern Leopard Frog
This frog has distinct spots on its back. It’s medium-sized and common near grassy areas. The call is a low, guttural snore.
- Size: 2 to 4.5 inches
- Color: Green or brown with dark spots
- Habitat: Meadows, marshes
- Call: Low, snoring sound
Pickerel Frog
Pickerel frogs look like leopard frogs but have square-shaped spots. They also have a yellow or orange wash on their inner thighs. The call is a low, snoring sound similar to the leopard frog.
- Size: 1.75 to 3.5 inches
- Color: Brown with square spots
- Habitat: Cold, clear streams
- Call: Low snore
Mink Frog
Mink frogs smell like mink when handled. They have a green back with dark spots and a yellow belly. The call is a series of short, rapid clicks.
- Size: 1.75 to 3 inches
- Color: Green with dark spots
- Habitat: Bogs, northern lakes
- Call: Rapid clicks
Wood Frog
Wood frogs have a dark mask across their eyes. They are brown and live in forests. The call is a quacking sound like a duck.
- Size: 1.5 to 3.25 inches
- Color: Brown with dark mask
- Habitat: Woodlands, vernal pools
- Call: Quacking
Treefrogs In Michigan
Treefrogs have sticky toe pads for climbing. They are small and often colorful. Michigan has three species.
Gray Treefrog
Gray treefrogs can change color from gray to green. They have a bright yellow patch on their inner thighs. The call is a short, musical trill.
- Size: 1.25 to 2.25 inches
- Color: Gray to green, yellow thighs
- Habitat: Trees, shrubs near water
- Call: Musical trill
Spring Peeper
Spring peepers are tiny frogs with a dark X on their back. Their call is a high-pitched “peep” that fills the air in early spring.
- Size: 0.75 to 1.25 inches
- Color: Brown or gray with X
- Habitat: Woodlands, marshes
- Call: High-pitched peep
Western Chorus Frog
Western chorus frogs have three dark stripes down their back. They are small and secretive. The call is a rising, raspy trill.
- Size: 0.75 to 1.5 inches
- Color: Gray or brown with stripes
- Habitat: Wet meadows, ditches
- Call: Raspy trill
Toads In Michigan
Toads have dry, warty skin and short legs. They are more terrestrial than frogs. Michigan has two species.
American Toad
American toads are common in gardens and yards. They have a bumpy back and a dark belly. The call is a long, musical trill.
- Size: 2 to 4.5 inches
- Color: Brown, gray, or olive
- Habitat: Gardens, forests, fields
- Call: Long trill
Fowler’s Toad
Fowler’s toads look similar to American toads but have a white belly and more spots. The call is a short, harsh trill.
- Size: 2 to 3.5 inches
- Color: Gray or brown, white belly
- Habitat: Sandy areas, fields
- Call: Short, harsh trill
How To Identify Frogs By Call
Listening is one of the best ways to identify frogs. Each species has a unique call. Here’s a quick guide.
- Bullfrog: Deep “jug-o-rum”
- Green Frog: Single “twang”
- Leopard Frog: Low snore
- Pickerel Frog: Low snore (similar)
- Mink Frog: Rapid clicks
- Wood Frog: Quacking
- Gray Treefrog: Musical trill
- Spring Peeper: High-pitched peep
- Western Chorus Frog: Raspy trill
- American Toad: Long trill
- Fowler’s Toad: Short, harsh trill
Record the call with your phone. Compare it to online recordings. This helps confirm your ID.
How To Identify Frogs By Habitat
Where you find a frog tells you a lot. Different species prefer different habitats.
- Permanent ponds and lakes: Bullfrog, green frog
- Streams and rivers: Pickerel frog, green frog
- Bogs and northern lakes: Mink frog
- Woodlands and vernal pools: Wood frog, spring peeper
- Wet meadows and ditches: Western chorus frog, leopard frog
- Gardens and fields: American toad, Fowler’s toad
- Trees and shrubs: Gray treefrog
Think about the time of year too. Spring peepers call in early spring. Bullfrogs call in summer.
Common Mistakes In Frog Identification
Many people confuse green frogs with bullfrogs. Look for the ridges on the green frog’s back. Bullfrogs lack these.
Leopard frogs and pickerel frogs are also easy to mix up. Check the spots. Leopard frogs have round spots. Pickerel frogs have square ones.
American toads and Fowler’s toads look alike. Look at the belly. American toads have dark bellies. Fowler’s toads have white bellies.
Another mistake is thinking all small frogs are spring peepers. Western chorus frogs are similar in size. Look for the three stripes on the chorus frog’s back.
Tools For Frog Identification
You don’t need expensive gear. A few simple tools help.
- Field guide: A book with photos and range maps
- Smartphone app: Apps like iNaturalist or FrogID
- Binoculars: For watching frogs from a distance
- Flashlight: For night spotting
- Camera: Take photos for later comparison
Always handle frogs gently. Wet your hands first. Frogs absorb chemicals through their skin.
Frog Conservation In Michigan
Some Michigan frogs are rare. The Blanchard’s cricket frog is a species of special concern. It has declined due to habitat loss.
You can help by protecting wetlands. Avoid using pesticides near ponds. Report sightings of rare species to the Michigan DNR.
Frogs are indicators of ecosystem health. A decline in frogs often means something is wrong with the environment.
Frequently Asked Questions
What is the most common frog in Michigan?
The green frog is one of the most common. You’ll find it in almost any wetland. The spring peeper is also very common in early spring.
How can I tell a bullfrog from a green frog?
Look for the ridges (dorsolateral folds) on the green frog’s back. Bullfrogs have no ridges. Also, bullfrogs are much larger.
Are there poisonous frogs in Michigan?
No native Michigan frogs are poisonous to humans. Some toads secrete a mild toxin that can irritate skin. Wash your hands after handling any amphibian.
What time of year do frogs call in Michigan?
Frogs call from early spring to late summer. Spring peepers start in March. Bullfrogs call in June and July. Some species call after rain.
Can I use a frog identification app in Michigan?
Yes. Apps like iNaturalist and FrogID are helpful. They use your location to suggest species. You can also upload photos for community identification.
Final Tips For Using This Michigan Frog Identification Guide
Start with the easiest features. Look at size and skin texture. Then check color and markings. Finally, listen for the call.
Practice in your own yard. You might find American toads under a porch light. Visit a local pond at dusk. You’ll hear green frogs and bullfrogs.
Keep a journal of your sightings. Note the date, location, and call. Over time, you’ll become an expert.
Remember, this Michigan frog identification guide is a starting point. The more you observe, the better you’ll get. Frogs are fascinating creatures. Enjoy learning about them.
If you find a frog you can’t identify, take a photo. Share it with a local nature group. Many people are happy to help.
Frog identification is a skill. It takes practice. But with this guide, you’re well on your way. Happy frog watching!