6 Types of Frogs Found in Montana! (ID Guide)
“What kind of frogs can you find in Montana?”
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 Montana.
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!
6 Frog Species in Montana:
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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 Montana!
Believe it or not, they can grow to weigh as much as 1.5 pounds (.7 kg). Unfortunately, these massive frogs are not native to Montana and were introduced from the eastern half of the country. Their giant appetites can be incredibly destructive to native ecosystems when they arrive.
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 Montana 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. 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 Montana, 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.
#4. Pacific Treefrog
- Pseudacris regilla
Identifying Characteristics:
- Adults can reach 2 inches long, with the males typically being smaller.
- Most are green or brown with pale white undersides, but some are reddish, gray, cream, or black.
- Dark mask across the eyes to the shoulders and uniformly bumpy skin.
The Pacific Treefrog can be found in a wide range of elevations in Montana, ranging from sea level to 10,000 feet (3,050 m)!
Pacific Treefrog Range Map
Look for them in woodlands and meadows. Interestingly, these frogs spend most of their time on the ground despite being a treefrog. They even hide from predators in underground burrows!
The Pacific Treefrog travels to the shallow water of ponds and lakes to breed and lay eggs. The female attaches the eggs to sticks or other underwater debris.
Also called the Pacific Chorus Frog, this species can be heard during the spring.
Their mating call is a two-part call that sounds like “kreck-ek” or “rib-bit.“
#5. Sierran Tree Frog
- Pseudacris sierra
Identifying Characteristics:
- Adults can reach 2 inches long, with males typically being smaller.
- Dark mask across the eyes to the shoulders and uniformly bumpy skin.
Sierran Tree Frogs are mainly found in Montana in forests.
Adults typically appear as shades of either brown or green. But interestingly, individuals can change colors over the course of a few hours to help them blend into their environment. So if you find one and come back to find it later, it may look completely different. 🙂
The Sierran Tree Frog has an interesting, if not confusing, history. These frogs used to be known as Pacific Tree Frog (Pseudacris regilla), but in 2006, a scientific paper came out that split Pseudacris regilla into three species:
- Pacific Tree Frog (Pseudacris regilla), Baja California Tree Frog (Pseudacris hypochondriac), and the Sierran Tree Frog.
Unfortunately, the paper did not provide any way to tell the difference between these three species, nor any maps as to where each one is primarily found. While this change has been controversial, it has stuck over the years.
#6. Columbia Spotted Frog
- Rana luteiventris
Identifying Characteristics:
- Green or brown with black spots on its back
- The upper lip and belly are white.
- Compared to other frogs, they have shorter back legs, upturned eyes, and a narrower snout.
You will almost always find Columbia Spotted Frogs near permanent bodies of water, such as ponds, lakes, slow-moving streams, and marshes. In addition, they need lots of vegetation to provide adequate protection because many different predators hunt them!
Females lay up to 1,300 eggs at a time in shallow water. Interestingly, once laid, this mass of eggs absorbs water and can grow to the size of a softball! And these eggs are not attached to anything, so they just float around until the tadpoles are ready to hatch.
To attract a female, male frogs will sing a song that ranges from long, deep sounds to clicks. You can listen to an example of the clicks below:
Do you need additional help identifying frogs?
Try this field guide!
Which of these frogs have you seen in Montana?
Leave a comment below!
