Frogs in Idaho

Idaho is located in the northwestern part of the USA.

This state is known for its mountains, outdoor recreation sites, and protected wildernesses. It is made up of a variety of forest habitats.

Fifteen (15) species of anurans reside therein. There are three (3) species of toads and twelve (12) species of frogs in Idaho. In this article, the focus is on the adults of the named species.

Below are listed the anuran species in the state, with brief descriptions of them. It is important to note common attributes and characteristics of anurans and the differences between them before going forward.

The most conspicuous difference between frogs and toads is the length of their limbs compared to their bodies. Most frogs have long hindlegs and slender bodies. On the other hand, toads usually have stocky bodies and shorter limbs.

On their hindlegs, frogs and toads have five digits. On their forelegs, they have only four digits. These toes are usually webbed together, although the extent of the webbing varies across species.

While frogs move by jumping and leaping, most toads move slower by walking or hopping. The average frog has moist and smooth skin, but toads typically have rough and warty skin. These warts produce poisons to deter predators.

To further protect themselves from predation, anurans have other techniques and adaptations. While the various techniques peculiar to each species will be discussed under its listing, adaptations are more general.

Frogs and toads are dorsally colored to match their environs, be it the ground, water, or trees. Ventrally, they are white, cream, or bright yellow in color. This is to avoid aquatic predators by blending with the light entering the water.

Also, they have widely spaced eyes for wide vision, external ears (called tympana; singular tympanum) to sense vibrations, and the ability to live both on land and in water. Some species are adapted to live in trees.

Nocturnality (activity at night) also protects some toads and frogs, as predators may not easily see them when they are covered by darkness. Others may be diurnal (active in the daytime) or crepuscular (active at dusk and dawn).

Adults are usually preyed on by birds, snakes, fish, raccoons, otters, salamanders, larger frogs, and sometimes humans. They are insectivorous, having a diet largely made up of insects and their larvae.

This article contains the following facts on the listed species: biological family, zoological name, other common names, snout-vent length (SVL), longevity, geographic range, habitat, physical attributes, mating call, behavior, and additional anti-predator techniques.

Unless otherwise stated, these species are not threatened or endangered. However, we humans must be more intentional and careful about our environment, to avoid making it less conducive for other organisms we share it with.

Species of Frogs in Idaho

1. Rocky Mountain Tailed Frog

• Family: Leiopelmatidae/ Ascaphidae
• Scientific Name: Ascaphus montanus 
• Other Names: N/A
• Adult Size: 3.8 to 5.7 cm (1.5 to 2.24 in)
• Lifespan: 7 or 8 years up to 15 to 20 years

The rocky mountain-tailed frog is endemic to North America, found only in the United States and Canada.

It is native to Oregon, Idaho, Montana, Washington, and British Columbia. It lives in the Rocky Mountains and the Columbia Mountains.

This frog likes to inhabit small and fast-flowing mountain streams with high gradients. It usually prefers permanent forested streams with clear, cold water, cobble or boulder substrate, and little silt.

Dorsally, they could be colored reddish brown, brown, or olive-gray with yellow or gray spots. Their skin is granulated in texture and they have a dark stripe on each eye. Ventrally, they are mostly colored cream, white, or a pinkish pallor.

Rocky Mountain-tailed frogs lack tympana. Males have a tear-shaped organ, the “tail”, for copulation with females and internal fertilization of eggs. Only this species and coastal-tailed frogs show internal fertilization of eggs.

Frogs of this species are most active at night and in humid weather. Otherwise, they remain underwater, hiding under rocks or debris.

Because they do not have vocal sacs, they do not vocalize, and so they have no mating calls.

2. Coastal Tailed Frog

• Family: Leiopelmatidae
• Scientific Name: Ascaphus truei 
• Other Names: Pacific tailed frog, Western tailed frog
• Adult Size: 2.2 to 5.1 cm (0.87 to 2.01 in)
• Lifespan: 2 to 9 years, up to 14 years

Coastal-tailed frogs are found in Canada and the USA, in British Columbia, California, Washington, and Oregon.

There is a different distribution of this species in Idaho and Montana as well. They live in or around cold and fast-moving streams.

For this reason, they show some adaptations that are not common in other frog and toad species. They have smaller lungs and their toe tips are hard to help them crawl among rocks at the bottom of streams.

They are small and dorsally colored by the substrate. Their dorsal color could be tan, chocolate brown, or olive green, and their skin is usually rough and bumpy. Their toes are slightly webbed with the outer toes of their hindlegs flattened.

A coastal-tailed frog’s head is flattened and big in comparison with the rest of its body. Between its snout and eyes, there is a light triangular-shaped mark. It also possesses a dark stripe from the snout to each shoulder.

These frogs are also not vocal, lacking tympana, ear bones, tongues, and vocal sacs. They show internal fertilization alongside the rocky mountain-tailed frogs. For this reason, they have a short and tail-like organ for copulation.

Males are slightly smaller than females. Males also develop black horny pads on their thighs to grip females in the breeding season. Coastal-tailed frogs are more nocturnal than diurnal, and they do not communicate by calls.

3. Boreal Chorus Frog

• Family: Hylidae
• Scientific Name: Pseudacris maculata
• Other Names: Pseudacris triseriata maculata 
• Adult Size: 3 to 3.8 cm (1.18 to 1.5 in)
• Lifespan: 2 to 3 years, record longevity of 6 years

The boreal chorus frog is endemic to North America. It is largely distributed in Canada and in some states of the USA. It is found in Canadian provinces like Yukon, Ontario, British Columbia, Manitoba, and Quebec.

This frog likes to live in open spaces and in forests with open canopies. It has been found in grasslands, roadside ditches, splash pools, swamps, shallow lakes, flooded fields, and around other freshwater sources without fish.

Boreal chorus frogs live comfortably in any such habitat where there is enough vegetation for cover and protection, and food in the form of insects. They are small frogs that have smooth, moist skin.

Their dorsal skin is usually colored in any shade from a greenish gray to brown. Three stripes can be noticed on their backs in a darker pigment than their dorsal color. These stripes may be broken.

From each eye to the groin, there is a dark stripe on these frogs. Between the eyes of some boreal chorus frogs, a dark triangular pattern may be seen. A white stripe, as has been noticed on most chorus frogs, runs across their upper lip.

Their bellies are usually white, yellowish, or cream, and there may be dark mottling on the chest and throat. Their long toes are adapted for climbing with small toe pads. Their feet are webbed and their snouts are pointed.

The call of a boreal chorus frog is a loud and chirping sound. It has been likened to the sound of drawing a finger down a comb’s teeth. It is short and may be repeated 30-70 times per minute.

Individuals are diurnal, nocturnal and crepuscular. They show more daytime activity in cooler months and more activity at dusk, night, and dawn in the hotter parts of the year.

In the breeding season, they are active both day and night.

4. Pacific Tree Frog

• Family: Hylidae 
• Scientific Name: Pseudacris regilla 
• Other Names: Pacific chorus frog, Northern Pacific treefrog 
• Adult Size: 1.9 to 5 cm (0.75 to 2 in)
• Lifespan: N/A

Pacific tree frogs live in North America, inhabiting Mexico, Canada, and the US. They can be found in US states such as Oregon, Alaska, Arizona, California, Nevada, Utah, Washington, and Idaho.

They are found in the Pacific Northwest area of North America as their name suggests. They live on land, in dense vegetation, especially around ponds, springs, swamps, streams, and several other damp places.

Between the eyes of an individual of this species, a distinct Y-shaped mark is noticed. It has black spots on its dorsal skin and legs. There are also two black stripes, starting from each shoulder and running through each eye.

Although largely terrestrial, they are biologically adapted for climbing. The ends of their toes have adhesive circular disks (toe pads) on them for gripping trunks, branches, and twigs. Females are larger than their male conspecifics.

Each individual pacific tree frog is colored differently dorsally and is colored in various hues itself. Coloration is however usually any shade from lime green to brown. The shade of their skin can change due to humidity and temperature.

These frogs are nocturnal. Their call is a deep and loud croak, a rapid “cree-creek”.

They can change color to avoid being seen by predators, but they cannot willingly change their dorsal coloration to match their surroundings.

5. Sierran Tree Frog

• Family: Hylidae
• Scientific Name: Pseudacris sierra
• Other Names: Sierran chorus frog
• Adult Size: 1.9 to 5.1 cm (0.75 to 2 in)
• Lifespan: N/A

The range of the Sierran tree frog is not clear or defined, but individuals of this species have been found in Nevada, Oregon, Idaho, Montana, and British Columbia. The frog lives in Canada and the USA.

Frogs of this species live in various habitats. They are usually seen far away from water outside the breeding season. Such habitats include grasslands, forests, caves underground, pastures, oases, desert streams, and urban areas.

Sierran tree frogs are small frogs with heads that are large in comparison to their body size. Their large eyes have a wide and dark-colored stripe running through each, from their snouts to their shoulders.

There is often a Y-shaped marking between the eyes of these frogs. They have slim waists with long and slender legs. Their toes are slightly webbed and they have small and sticky pads to aid climbing.

Dorsally, this frog is usually colored green or brown, but there are some in tan, gray, reddish, or cream color. Ventrally, it is colored pale white with some yellow hue under the hindlegs. It can change its dorsal color in response to its environment.

The males have darker throats that are wrinkled. Although members of the tree frog family, Sierran tree frogs are mostly terrestrial, living among grasses and shrubs near water. However, they are sometimes found living high in trees.

They are both diurnal and nocturnal, showing more nocturnal activity in dry periods and more daytime activity in wet ones. They use two different mating calls: a two-part (diphasic) “rib-it” or “krek-ek”, and another one-part (monophasic) call.

Sierran tree frogs also make use of encounter calls, release calls, and land calls. To avoid predation, they change their body color and stay still.

If threatened, they leap a long way, jumping into the water and swimming into the vegetation to hide.

6. American Bullfrog

• Family: Ranidae 
• Scientific Name: Lithobates catesbeianus 
• Other Names: Rana catesbeianus, bullfrog, North American bullfrog 
• Adult Size: 9 to 15.2 cm (3.5 to 6 in)
• Lifespan: 7 to 9 years in the wild, up to 16 years in captivity

American bullfrogs are large frogs widespread across Canada and the United States.

They can be found in different natural and man-made habitats. They live in or around large permanent bodies of water like swamps, ponds, marshes, lakes, canals, rivers, and streams.

Dorsally, they could be colored in dark or bright shades of green or greenish brown. Their arms and legs are covered in dark spots. Their backs and sides may be solid colored or full of dark dots and patterns.

They are powerful swimmers with long legs. They have large and webbed feet, with wide and flat heads. The males and females show sexual dimorphism by differences in tympanum size and throat color.

Males’ tympana are much larger than their eyes and their throats are yellow. Females’ tympana are either smaller than or the same size as their eyes. Their throats are usually white or cream in color.

Because they are large in size, bullfrogs are able to prey on animals other than insects. They eat species of frogs that are smaller than themselves. As a result, there are several frog species endangered due to their activity.

They are both diurnal and nocturnal, but mostly active when the weather is moist and warm. They like the warm weather because they are cold-blooded.

Their call is very deep and resonant, likened to a rumbling “jug-o-rum” sound.

7. Columbia Spotted Frog

• Family: Ranidae 
• Scientific Name: Rana luteiventris
• Other Names: N/A
• Adult Size: 4.6 to 10 cm (1.81 to 3.94 in)
• Lifespan: 3 to 13 years in the wild

Another species of frog in Idaho is the Columbia spotted frog. They occur in North America, in states of the US and Canadian provinces, including Alaska, Yukon, British Columbia, Alberta, Montana, Wyoming, Oregon, and Nevada.

Still and slow-moving sources of freshwater are ideal for frogs of this species. They are mostly found living in, around, or along the banks of ponds, streams, lakes, and slow-moving streams.

A Columbia spotted frog is medium or average-sized. Its back could be tan, brown, or olive green in color. Dark and irregularly shaped spots are scattered across its back, legs, and sides. Ventral coloration is white, off-white, or yellow.

Along its upper lip is a yellowish or white line. It has a narrow snout, shorter legs, and webbed feet. Its skin has rough dorsal folds on it.

It is diurnal, with a call low in pitch that sounds much like rapid knocking or clucking.

A Columbia spotted frog is able to startle its predators by an alarm call. This alarm call is a 6-second shriek.

8. Northern Leopard Frog

• Family: Ranidae
• Scientific Name: Lithobates pipiens
• Other Names: Rana pipiens, grass frog, meadow frog
• Adult Size: 5 to 11.5 cm (1.97 to 4.37 in)
• Lifespan: up to 9 years in the wild

The northern leopard frog species is native to North America and found in Canada and the USA. Individuals are found in Idaho, Arizona, California, Colorado, Nevada, Oregon, Utah, British Columbia, Virginia, and Washington.

They are found in a variety of habitats, including marshlands, brushlands, and forests. They prefer to live in or along still or slow-moving water with lots of vegetation and open space.

Northern leopard frogs are medium or average-sized. The dorsal coloration of these frogs is usually green or greenish brown. There are also brown round spots arranged on their backs, sides, and legs, resembling a leopard’s spots.

A distinct white fold runs down their backs. This dorsolateral fold extends from each eye of these frogs. From their nose to each shoulder, a white line is also seen running across their mouths.

The ventral coloration of this species is usually white or greenish white. Males are typically smaller in size than females. These males have thickened thumb pads specialized for gripping females while mating and paired vocal sacs.

Northern leopard frogs are nocturnal. Their calls sound like a low and rumbling snore with clicks and croaks occasionally heard in between the snore-like sound. When threatened, they hop away while squawking or screaming.

They also employ mimicry by occurring with pickerel frogs, mimicking them, and taking advantage of the resemblance to avoid predation. Pickerel frogs look like these frogs.

They secrete poisons that are harmful to and deter attackers.

9. Wood Frog

• Family: Ranidae 
• Scientific Name: Lithobates sylvaticus 
• Other Names: Rana sylvatica, the frog with the robber’s mask 
• Adult Size: 3.8 to 8.2 cm (1.5 to 3.25 in)
• Lifespan: 3 to 5 years in the wild

The wood frog is another species of frog in Idaho. It is widely distributed across North America, commonly found in several places within the United States and Canada.

This frog lives mostly on the ground or around trees, but it can also be found in marshes, swamps, meadows, and mixed forests. Woods frogs leave their primary habitats in the breeding season, migrating to semi-permanent water bodies.

A wood frog has mask-like markings across its eyes, hence its other common name. These markings are black patches from each tympanum to the base of each of its forelegs. A white outline is also present, across its upper lip.

Frogs of this species come in different shades of gray, green, brown, tan, and rust. A mid-dorsal fold is also present, running down their backs in a bright yellow-brown color. Ventrally, the frogs are white.

Wood frogs show sexual dimorphism. Males are smaller in size with the ventral part of their legs colorful. Females’ white bellies fade to a yellow-orange pallor towards the legs, and they are more brightly colored dorsally than the males.

Individuals of this species are more diurnal, actively scrounging and feeding during the day. The males have a mating or advertisement call that sounds much like a chicken clucking.

Wood frogs produce poisons to irritate predators in case of capture or attack. When captured, this frog lets out a piercing cry.

This cry may startle the predator, or annoy such attacker enough for it to let the frog go.

10. Cascades Frog

• Family: Ranidae 
• Scientific Name: Rana cascadae 
• Other Names: N/A
• Adult Size: 5 to 7.5 cm (1.97 to 2.95 in)
• Lifespan: up to 3 years in the wild

Cascade frogs are native to the Cascade Range, a mountain range in North America that cuts through parts of British Columbia, Washington, Oregon, and California. They are found in Canada and the USA.

They are a near-threatened species, with populations declining as a result of pollution and ozone layer depletion. These frogs like to live in shallow ponds, mountain meadows, forests, marshes, or small streams.

They are medium-sized frogs with long legs and are usually brown, olive-brown, or olive dorsally. They have well-defined spots in darker pigment on their backs.

The belly of a cascade frog is a lighter color towards the groin and beneath the legs, with mottling around the groin. This color could be yellow, yellow-orange, or a yellowish tan. The dorsal part of their legs is also spotted in black.

There is a fold on each side of this frog, running along the length of its back. Its toes are not fully webbed, and the thumbs are swollen and darkened in males. Females are slightly larger in size.

Cascades frogs are a diurnal species, showing more activity in the daytime. Their mating call is a series of rapid clucking or low-pitched chuckling, each lasting for half a second.

They move slowly but try to swim faster when they sense danger.

11. Oregon Spotted Frog

• Family: Ranidae 
• Scientific Name: Rana pretiosa 
• Other Names: N/A
• Adult Size: 4.5 to 10 cm (1.8 to 3.94 in)
• Lifespan: usually over 3 years

Oregon spotted frogs are native and endemic to the Pacific Northwest and the Cascade Mountains.

They are found in parts of Canada and the USA. They have been listed as a vulnerable species, with populations decreasing.

They are highly aquatic and so live in wetlands, breeding in shallow ponds with grasses and hibernating in streams and springs. There are about three localities of this frog in British Columbia, four in Washington, and twenty-four in Oregon.

Oregon spotted frogs are mostly colored brown, reddish brown, or red on their backs. The dorsal skin on the back and sides of the frog is covered in tubercles and bumps. The frog’s back, legs, and sides have black spotting as well.

These large dots are irregularly shaped, their edges are indistinct and the middle of the dot is colored lighter than the edges. Ventral coloration towards the groin and beneath the hindlegs is usually reddish-orange or salmon colored.

Oregon spotted frogs have relatively short hind legs. The toes of their hind legs are webbed extensively. There is a size disparity between the sexes, as females are much bigger than males. They are nocturnal.

Their call is a series of 5 to 50 rapid notes that sound like tapping. They are a rare and vulnerable species.

This is probably due to urbanization, habitat alteration and loss, predators, introduced competitors, and drainage of habitat.

12. Northern Red-Legged Frog

• Family: Ranidae
• Scientific Name: Rana aurora
• Other Names: N/A
• Adult Size: 5 to 13 cm (2 to 5.25 in)
• Lifespan: up to 15 years in captivity

Red-legged frogs are native to Oregon and California.

Some have been found in British Columbia, Canada. There are two subspecies: Rana aurora aurora (Northern red-legged frog) and Rana aurora draytonii (California red-legged frog).

These frogs occur around the banks of still or slow-moving ponds and streams. They like habitats with vegetation to cover and protect them from predation, the heat of the sun, and the cold of winter.

Their dorsal color is usually reddish brown or gray, and they have several undefined splotches on their backs in a darker color. There is a light stripe on their jaw and folds on their back and sides.

Ventrally, they are colored yellow, with streaks of red on the underside of the lower abdomen and back limbs. Their toes are not fully webbed. Differences exist between the subspecies.

While the northern subspecies lack vocal sacs, the California subspecies have paired vocal sacs. The northern subspecies have smooth and thin skin without spots. California red-legged frogs are bigger and have rougher skin with light-centered spots on it.

Differences exist between sexes as well. While females grow to a larger size than their male conspecifics do, males have larger forearms and swollen thumbs.

These diurnal frogs flee into the water, swimming to its depths, as a response to an attack from a predator.

Species of Toads in Idaho

13. Great Basin Spadefoot

• Family: Scaphiopodidae
• Scientific Name: Spea intermontana
• Other Names: Scaphiopus intermontanus, Great Basin spadefoot toad 
• Adult Size: 3.2 to 6.7 cm (1.26 to 2.64 in)
• Lifespan: 11 to 13 years in the wild

Great Basin spadefoots are found in Canada and the USA, in California, Nevada, Colorado, Idaho, Wyoming, Nevada, Utah, Oregon, British Columbia, and Washington. They are adapted for living in xeric conditions.

These toads are found in dry areas like deserts, semi-desert shrublands, dunes, scrub forests, and mountains. They are able to survive such arid habitats by burying themselves in the burrowing friendly loose soils of these habitats.

Dark spots with brighter colored centers can be seen on the dorsal skin of a Great Basin spadefoot. This skin is typically gray, brown, or olive in color. There is also a marking shaped like an hourglass on its back, outlined in gray.

Its venter is white, creamy, or light gray, with no markings on it. In comparison to the skin on the backs of most toad species, the dorsal skin of this species is smooth. Small bumps can still be found on it.

These toads have a dark brown or orange spot on each of their upper eyelids. Their limbs and body are short, fat, and stubby, with females slightly larger than males. Like other spadefoot toad species, this one has a spade-like tubercle under each hindleg for burrowing.

Breeding does not take place at a particular time of each year for Great Basin spadefoot toads. Their calls are loud, duck-like snoring sounds.

They are nocturnal but also show activity early in the morning and late in the afternoon.

14. Western Toad

• Family: Bufonidae 
• Scientific Name: Anaxyrus boreas 
• Other Names: Bufo boreas, boreal toad, alkali toad, California toad, Southern California toad
• Adult Size: 5.6 to 13 cm (2.2 to 5.1 in)
• Lifespan: 9 to 11 years

The western toad is another species of toad in Idaho.

These toads are found in other US states like Utah, Alaska, Oregon, California, Montana, Nevada, Washington, and Wyoming. They also occur in parts of Canada and Mexico.

This species of toads prefer to live in mountainous areas but can also occupy desert streams and springs, mountain meadows, and grasslands. They are found in or near ponds, streams, lakes, and rivers.

The dorsal coloration of a western toad is usually dusky gray or greenish. A stripe runs down its back, and this line is white or cream in color. Black or dark-colored splotches can be noticed on this toad’s dorsal surface.

Ventral coloration is white and the surface is mottled. Toads of this species have oval and widely spaced parotid glands. They are larger than the toad’s upper eyelids. Cranial crests are absent in this species.

Some sexual dimorphism is evident in this toad species. Males have smoother skin, fewer blotches on their backs, and nuptial pads on their toes for gripping the females during the breeding season.

The dorsal skin of the female toads is rougher in texture than that of the males. They have many blotches on their skin and lack nuptial pads on their toes. Both male and female western toads are nocturnal.

The call of this toad species is quite peeping likened to the sound of little chicks. Like other toads, their anti-predator mechanism is the poison produced by their parotid glands and warts on their skin.

15. Woodhouse’s Toad

• Family: Bufonidae 
• Scientific Name: Anaxyrus woodhousii 
• Other Names: Bufo woodhousii, rocky mountain toad
• Adult Size: 4.4 to 12.7 cm (1.75 to 5 in)
• Lifespan: maximum 13 years

Woodhouse’s toads are found in several populations in states of the US like Arizona, Louisiana, Idaho, Texas, Montana, Oregon, Nevada, New Mexico, California, and North Dakota. Some have also been found in Mexico.

They occur in different habitats, including temporary, semi-permanent, and permanent water bodies. They inhabit moist meadows, ponds, irrigation ditches, temporary pools, grasslands, farms, desert streams, and even golf courses.

Their dorsal skin is usually gray, brown, olive, green, yellow-green, or yellow, with dark blotches scattered on it. A dorsolateral stripe running from their snouts down their backs is present in white or whitish color.

Ventrally, Woodhouse’s toads are pale cream or beige, and individuals may have their bellies mottled. Black and yellow marks can be noticed on the ventral surfaces of the groin and thighs.

They are large toads that have warts on their skin. Their cranial crests are prominent. Sometimes, a protrusion touching the separate parotid glands can be noticed between these cranial crests.

Woodhouse’s toads are nocturnal but they can sometimes be seen moving around in the daytime when they are not underground. Not much activity is noticed from them in the winter and so it is speculated that they hibernate.

Their call sounds like the muted bleating of a sheep bleating or a muted snore. This call typically lasts 1-4 seconds.

Their defense, like other toad species, is the poisonous secretions from their skin that deter their predators.

FAQs

Conclusion

Although not all native to the state, there are fifteen (15) anurans species known to live in Idaho: twelve (12) frog species and three (3) toad species. While some are abundant, others are endangered.

These anurans may not be seen much outside their breeding season and in the winter. In the breeding season, they come together in large numbers and take choruses. During the cold winter, they hibernate to survive.

Frogs and toads are important in our ecosystem and to our environment. They eat insects that are household and crop pests and provide food to larger animals up the food chain. Their calls also add to the magical beauty of nighttime.

Several human activities that are meant to make life more comfortable for us have led to declining in some anuran populations. A few are urbanization, with some harmful impacts on the ecosystem, and the use of off-road vehicles.

Different frog species make good pets for children and the household. This is because they are usually not harmful or irritant to humans.

Toads are toxic, however, and so may not be the best options for household pets.

Nearby states

• Frogs in Montana
• Frogs in Nevada
• Frogs in Oregon
• Frogs in Utah
• Frogs in Washington
• Frogs in Wyoming

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