Western Narrow-Mouthed Toad

Image of a western narrow-mouthed toad
Scientific Name
Gastrophryne olivacea
Microhylidae (narrow-mouthed toads) in the order Anura (frogs)

Like the eastern narrow-mouthed toad, this species has a plump body, small pointed head, and a fold of skin behind the eyes. This species is typically uniform in color, ranging from tan to gray or olive green, with few markings. The belly is white. Call is a high-pitched short peel sound that sounds similar to the buzz of a bee and lasts 1–4 seconds.

Similar species: The eastern narrow-mouthed toad has a darker overall color as well as a pattern of dark markings on the back. Also, its call is a bleating, nasal baaaa, like the cry of a lamb, and is nothing like the call of the western narrow-mouthed toad. These two species often occur in the same areas, but their mating calls are so different they don’t interbreed and hybridize.

Other Common Names
Great Plains Narrow-Mouthed Toad

Length (snout to vent): ⅞ to 1½ inches.

Where To Find
Western Narrow-Mouthed Toad

Western Missouri and along the Missouri River floodplain.

This species prefers grasslands, rocky and wooded hills, and areas along the edge of marshes. They spend most of their time hiding in loose soil, under rocks, boards, logs, or other objects, and have been known to hide in animal burrows.

Mostly ants. This species has evolved a toxic skin secretion that may protect it from ant bites, since it tends to sit on anthills while eating its preferred food.

This species used to be called the Great Plains narrow-mouthed toad.

Life Cycle

Breeding occurs from late May to early July. Warm, heavy rains stimulate males to congregate at ditches, temporary ponds, flooded fields, or pools in wooded areas. Special glands on the male’s belly secrete a gluelike substance that sticks the mating pair together. The female lays up to 645 eggs as a film on the water surface. These hatch in 2–3 days, and the tadpoles transform into froglets 20–30 days later.

As predators, these amphibians help control populations of many insects that are pests to humans. Additionally, their weirdly beautiful, strange-sounding choruses add to the magic of a Missouri evening.

Narrow-mouthed toads are predators that help keep populations of ants and other insects in balance. They, and especially their eggs, tadpoles, and young toadlets, become food for both aquatic and terrestrial predators ranging from water bugs to fish to grackles to raccoons.

Media Gallery
Similar Species
About Reptiles and Amphibians in Missouri
Missouri’s herptiles comprise 43 amphibians and 75 reptiles. Amphibians, including salamanders, toads, and frogs, are vertebrate animals that spend at least part of their life cycle in water. They usually have moist skin, lack scales or claws, and are ectothermal (cold-blooded), so they do not produce their own body heat the way birds and mammals do. Reptiles, including turtles, lizards, and snakes, are also vertebrates, and most are ectothermal, but unlike amphibians, reptiles have dry skin with scales, the ones with legs have claws, and they do not have to live part of their lives in water.