Frogs in Wyoming

Frogs and toads are of some importance to the environment and ecosystem.

They are collectively called anurans, the order of amphibians without tails. In Wyoming, there are eleven (11) anuran species present.

These small animals play the role of pest control, eating the insects and non-insect arthropods that are pests to crops and households. They are in turn eaten by larger animals up the food chain.

There are six (6) species of toads and five (5) species of frogs in Wyoming. This article, with a focus on adults, lists and provides information on the various species. Beforehand, it is important to state some common characteristics.

Both frogs and toads go through three stages of development (metamorphosis), from egg to larva and then to adult. The females’ eggs are fertilized externally by the males’ sperm except in frogs of the family Ascaphidae (tailed frogs).

Reproduction occurs usually in the spring; this is called the breeding season. In this season, these animals who prefer a solitary life during other times of the year come together in large numbers at breeding pools.

Males take breeding choruses, calling out to females using mating or advertisement calls which are peculiar to each species. Interested females come and make their choices, they mate, and external fertilization occurs in water.

Anurans have several mechanisms against predation. Their dorsal skin matches their surroundings in color to blend them in and avoid the attention of terrestrial predators. Their ventral skin is colored brightly to avoid aquatic predators.

Toads secrete toxins from their parotid glands and warty skin. These are produced when they are attacked or threatened. Some species of frogs are also poisonous but most are not, so frogs are more ideal pets than toads.

Also, most species are nocturnal, showing heightened activity at night. Others are however crepuscular (showing most activity at dusk and dawn) or diurnal (showing most activity in the daytime). Some combine more than one.

Frogs and toads have some differences, the most conspicuous being the quality of their skin. Frogs on average have moist and smooth skin, while toads have rougher skin covered in warts.

In addition, frogs have more slender bodies and longer legs so they move by jumping or leaping. Toads’ stockier bodies and shorter legs make them move more slowly. Their movement is by walking or hopping.

With a focus on the adults, this article lists the species of toads and frogs in Wyoming, including brief descriptions. Such peculiar information as geographic range, morphological features, calls, and behaviors are stated below.

Species of Frogs in Wyoming

1. American Bullfrog

• Family: Ranidae 
• Scientific Name: Lithobates catesbeianus 
• Other Names: Rana catesbeianus, American bullfrog, North American bullfrog
• Adult Size: 9 to 15.2 cm (3.5 to 6 in), record length 20.3 cm (8 in)
• Lifespan: 7 to 9 years in the wild, up to 16 years in captivity

The American bullfrog is a species of frog native to North America, living in parts of the USA, Canada, and Mexico. It has been introduced to some other continents like Asia, Europe, and South America.

They are the largest true frogs in North America. This highly aquatic species lives around water bodies, preferring warm, still, and shallow water. Individuals are usually found around bogs, lakes, rivers, or ponds.

Dorsally, American bullfrogs could be colored in any shade of brown or green. They have spots of darker color on their backs and webbed hind limbs. There is sexual dimorphism in this species.

While males have yellow throats in the breeding season, females have white throats. The male’s tympanum is much larger than its eye. In females, the tympanum is smaller than or the same size as the eye.

American bullfrogs are both nocturnal and diurnal, but they are most active when the weather is warm and humid. Their low and rumbling calls, which have been described as a “jug-o-rum”, can be heard from far distances.

In addition to insects, these frogs eat snakes, salamanders, crustaceans, smaller frogs, and other terrestrial vertebrates. They are eaten by humans as a source of frog legs but not by some animals, especially fish, because of their foul taste.

2. 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 cm)
• Lifespan: 2 to 3 years, record lifespan of 6 years

Boreal chorus frogs are found in North America, Canadian regions, and states of the USA. Some regions of Canada that they inhabit include Yukon, Ontario, British Columbia, Manitoba, and Quebec.

They prefer living in open spaces and forests with an open canopy. As long as enough vegetation for cover and food in the form of insects are present, frogs of this species live comfortably in the area.

Boreal chorus frogs can be found in grasslands, marshy streams, roadside ditches, splash pools, beaver ponds, swamps, shallow lakes, flooded fields, and around other freshwater sources without fish.

These small frogs have smooth, moist skin. Their dorsal color is usually any shade from greenish gray to brown. They may have three often broken stripes on their backs in a darker pigment than their dorsal color.

From each eye to the groin, there is a visible dark stripe on them. A dark triangular pattern is also seen on the head of some boreal chorus frogs, between their eyes. Like on other chorus frogs, a white stripe runs across their upper lip.

Underneath them, the ventrum is usually white, yellowish, or cream, possibly with dark mottling on their chests and throats. They have long toes adapted with small toe pads for climbing. Their feet are webbed and their snouts pointed.

A male boreal chorus frog calls with a loud chirp-like sound likened to the sound of drawing a finger down a comb’s teeth. This call is short and may be repeated 30 to 70 times per minute.

The species is diurnal, nocturnal, and crepuscular. Individuals show more daytime activity in cooler months.

More activity at dusk, night, and dawn is shown in the hotter parts of the year. In the breeding season, they are active both day and night.

3. 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

The Columbia spotted frog occurs in North America, in states of the US and Canadian provinces. Such places include Alaska, Yukon, British Columbia, Alberta, Montana, Wyoming, Oregon, and Nevada.

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

The average-sized Columbia spotted frog could be tan, brown, or olive green in color dorsally. Dark and irregularly shaped spots are scattered across its back, legs, and sides. Ventrally, it is colored white, off-white, or yellow.

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

It is diurnal, with a low-pitched call that sounds much like rapid knocking or clucking. A Columbia spotted frog is able to startle its predators using an alarm call.

This alarm call is a shriek that typically lasts about 6 seconds.

4. 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 4.5 in)
• Lifespan: up to 9 years in the wild

This species of frog in Wyoming is native to regions of Canada and the United States.

It is the state amphibian of Minnesota and Vermont. It also lives in Washington, Oregon, Utah, Arizona, New Mexico, and Nevada.

Northern leopard frogs occur most frequently around permanent, slow-moving water with aquatic vegetation. They move far from the water when the breeding season is over and they prefer living in open spaces to living in woodlands.

Dorsally, their skins are green, yellow-green, or greenish brown in color. Their smooth skin is covered in large oval spots, with each spot bordered by a halo of lighter pigment. This spotting is the reason they are called leopard frogs.

Ventrally, they are usually white or cream. Two distinct ridges are present on the back of the northern leopard frog, running along each side. Males are smaller than females on average, possessing large thumb pads and dual vocal sacs.

They migrate to ponds during spring to breed and leave for grasslands or meadows in the summer. They are more nocturnal when breeding and more diurnal when foraging. The call of this frog is short and sounds like snoring.

Northern leopard frogs avoid their predators by leaping quickly and blending into a vegetated environment. Some take advantage of their likeness to pickerel frogs and live around them to avoid being eaten.

5. 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 a species commonly distributed across North America and found in several locations in the US and Canada. It leaves its primary habitat to breed, preferring to breed in semi-permanent water bodies.

They spend most of their time in the ground or around trees, but can also be found in marshes, swamps, meadows, coniferous forests, deciduous forests, and mixed forests.

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

These frogs come in various shades of gray, green, brown, tan, and rust. A lateral fold is also present, running down the center of their backs in a bright yellow-brown color. Ventrally, the frogs are white.

There are however some differences between the sexes. Male wood frogs are smaller in size. The ventral part of their legs is also colorful. On the other hand, female wood frogs are bigger than male ones.

Their white bellies fade to a yellow-orange pallor towards the legs. The females are more brightly colored dorsally than the males. Frogs of this species are more diurnal than nocturnal. Their call sounds much like the clucking of a chicken.

Wood frogs produce poisons to irritate predators. When captured, they let out an alarm call, which is a piercing cry. This cry may startle the predator and annoy this attacker enough to let the frog go.

Species of Toads in Wyoming

6. 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 California, Nevada, Colorado, Idaho, Wyoming, Nevada, Utah, Washington, Oregon, and British Columbia. They have adaptations that help them live in xeric (extremely dry) conditions.

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

On the dorsal skin of the Great Basin spadefoot, there are dark spots with their center more brightly colored. The skin is typically gray, brown, or olive in color. A marking shaped like an hourglass is also present on its back, outlined in gray.

The ventrum is white, cream-colored, or light gray and it lacks markings. Compared to the skin on the backs of most true toads, the skin on the back of this species is smooth. There are still small bumps found on it, however.

They have a dark brown or orange spot on each of their upper eyelids. Their limbs and body are short, fat, and stubby. The female toads tend to be slightly larger in size than their male conspecifics.

Like other species of spadefoot toads, the Great Basin spadefoot has a spade-like tubercle under each hindleg for burrowing. Breeding does not take place at a particular time of each year for this toad species.

Their calls are duck-like snoring sounds. These loud calls are used to attract females for mating. They are primarily nocturnal but they also show activity early in the morning and late in the afternoon.

7. Great Plains Toad

• Family: Bufonidae
• Scientific Name: Anaxyrus cognatus
• Other Names: Bufo cognatus
• Adult Size: 4.8 to 11.4 cm (1.9 to 4.5 in)
• Lifespan: up to 10 years in captivity

Toads of this species can be found from the southwest region of Manitoba, Canada to central US states like Utah and California. They also live in Mexican states like Durango and Chihuahua.

Great Plains toads can be found in damp sections of grasslands and arid areas. They live in temperate areas, deserts, savannas, temporary rain pools, reservoirs, and river floodplains.

They are average or medium-sized, with small heads and well-developed cranial crests. Their blunt snouts are rounded and their dorsal color is usually yellowish, greenish, brown, or gray. A light and narrow stripe may run down their backs.

There are large dark blotches on their backs bordered by a halo of lighter pigment. Each blotch has many warts on it.

The skin is very rough because of warts on it. Ventral coloration is cream to white without spots.

They are primarily nocturnal but sometimes they can be active during the daytime. Their call is a high-pitched trill like that of American toads, but it is more mechanical and compelling.

8. Plains Spadefoot

• Family: Scaphiopodidae
• Scientific Name: Spea bombifrons
• Other Names: American spadefoot, European spadefoot, Plains spadefoot toad
• Adult Size: 3.8 to 6.35 cm (1.5 to 2.5 in), record SVL 6.5 cm (2.56 in)
• Lifespan: up to 13 years

The Plains Spadefoot ranges from southern Canada through the United States and into northern Mexico. It can be found in Iowa, Kansas, Montana, Nebraska, North Dakota, Utah, Wyoming, Alberta, Manitoba, and Saskatchewan.

They prefer to live in grasslands with loose soil. This is because they like to burrow into the ground, like other spadefoot toads, and areas conducive and easy enough to burrow into.

On the head of an individual of this species, a pronounced round protuberance, also called a boss, can be noticed between the eyes. Its skin could be brown or gray with a greenish tinge.

Four vague longitudinal stripes may be noticed on its back. Its warts could be yellow or orange in color. However, the skin is moist and smoother than most toads’ skins, more like a frog’s skin.

Their toes are webbed and there is a single tubercle on the hindleg of a plain spadefoot. The tubercle is wedge-shaped and spade-like, an adaptation for burrowing. They are nocturnal and are most active during the rains.

These toads are largely terrestrial. They are considered vulnerable, as it is quite common but individuals are rarely seen across its geographical range. The call of a plain spadefoot is short and sounds like a duck.

The species has two distinct calls; one is low-pitched and raspy like a snore, lasting for approximately one second. The other call is short, resonant, and bleat-like, lasting for approximately half a second.

9. 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

Western toads are found in North America, in US states like Utah, Alaska, Oregon, California, Idaho, 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 color 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.

There is sexual dimorphism 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 female western toads is rougher in texture than males’. They have many blotches on their skin and lack nuptial pads. These nocturnal toads use a quiet peeping call likened to the sound of little chicks.

10. Woodhouse’s Toad

• Family: Bufonidae
• Scientific Name: Anaxyrus woodhousii
• Other Names: Bufo woodhousii
• Adult Size: 6 to 10 cm (2.4 to 3.94 in)
• Lifespan: 10 to 20 years, record longevity of 36 years

Woodhouse’s toads are found in several states of the US like Wyoming, Nebraska, Arizona, Louisiana, Idaho, Texas, Montana, Oregon, Nevada, New Mexico, Utah, California, and North Dakota. They also occur in parts of Mexico.

They live in several habitats — temporary, semi-permanent, and permanent water bodies. Moist meadows, ponds, irrigation ditches, temporary pools, grasslands, farms, desert streams, and even golf courses house these toads.

Their dorsal skin is usually colored gray, brown, olive, green, yellow-green, or yellow, and it has dark blotches on it. A dorsolateral stripe running up to their snout is present in white or whitish color.

Ventrally, Woodhouse’s toads are pale cream or beige, and individuals may have their bellies mottled or not. Black and yellow marks can be noticed towards the ventral groin and thigh areas.

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

They are nocturnal, most active during the night, but they are sometimes seen moving around in the daytime when they are not underground. Their call sounds like a sheep bleating but muted, or a snore. This call typically lasts 1 to 4 seconds.

11. Wyoming Toad

• Family: Bufonidae
• Scientific Name: Anaxyrus baxteri
• Other Names: Baxter’s toad
• Adult Size: about 6.35 cm (2.5 in)
• Lifespan: N/A

The Wyoming toad is only found in the Laramie Basin of Albany County in the southeastern part of Wyoming. It lives in floodplains, ponds, and small lakes. It is a burrowing animal that digs in mounds.

On their backs, these toads are usually colored greenish, dark brown, or gray. Small black blotches are scattered along their dorsal surface. An inconspicuous line runs along the middle of their backs.

Some Wyoming toads have light stripes on their skin. Round warts are found on their bodies, and there are well-developed tubercles on their hindlegs for cutting. They are found in elevations from 1,000 to 7,000 feet.

Their bellies are spotted and their cranial crests are fused. There is slight dimorphism between the sexes, as males usually have darker throats than females and females are larger on average than males.

This species of toad is considered to be on the brink of extinction. Their low-pitched calls can be heard as far as 200 meters away.

It is a buzz lasting 1.3 to 5 seconds with 80 or more individual trills per second.

FAQs

Conclusion

Wyoming is inhabited by eleven (11) species of anurans: six (6) toad species and five (5) frog species. These include abundant species like American bullfrogs and northern leopard frogs and endangered or near extinct ones like the Wyoming toad.

Several species are endangered for different reasons, and some are caused or fueled by human activities. Some of these reasons are habitat loss, prolonged drought, disease, and natural or introduced predators (like American bullfrogs).

Hibernation is a coping mechanism used by several animal species for the winter, and aestivation is a coping mechanism for the summer. Some frogs and toads will bury themselves underground in extreme heat to avoid desiccation (drying up).

Anurans are fascinating animals and they make good first pets as long as they are not poisonous. Most frogs are not poisonous and so they are better choices.

They are small, affordable to purchase, and easy to take care of.

Nearby states

• Frogs in Colorado
• Frogs in Idaho
• Frogs in Montana
• Frogs in Nebraska
• Frogs in South Dakota
• Frogs in Utah

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