Amphibians
Great Plains Narrowmouth Toad
Gastrophryne olivacea · also called western narrow-mouthed toad
Tucked inside the entrance of a tarantula’s burrow, a Great Plains narrowmouth toad goes about picking off ants that might otherwise threaten the spider’s eggs, an unlikely roommate arrangement that benefits a toad built almost entirely for this one specific job.
Overview
The Great Plains narrowmouth toad, Gastrophryne olivacea, is a small, ant-eating amphibian native to grassland and prairie habitat across the central United States. Its narrow, specialised head shape and documented habit of sheltering inside tarantula burrows make it one of the more behaviourally unusual small toads in North America.
A toad built around a single food source
While most toads eat a broad mix of invertebrates, the Great Plains narrowmouth toad has narrowed its focus almost entirely to ants and termites, shaping its entire head around the specific challenge of raiding a colony rather than catching general prey.
Status
Least Concern — widespread and common across suitable grassland habitat throughout the central United States.
Great Plains Narrowmouth Toad: common questions
Why does the Great Plains narrowmouth toad have such a pointed head?
A Great Plains narrowmouth toad has a distinctly narrow, pointed head and small mouth, an adaptation well suited specifically to feeding on ants and termites, allowing the toad to probe into the tight spaces of an ant colony or termite nest rather than relying on the wider gape most other toads use for larger prey.
Does the Great Plains narrowmouth toad really live with tarantulas?
Some individuals have been documented living inside tarantula burrows, a relationship in which the toad may feed on ants that would otherwise threaten the tarantula's eggs, while the toad in turn gains a safe, sheltered place to live, a genuinely unusual example of two very different animals apparently benefiting from close cohabitation.
How does the Great Plains narrowmouth toad avoid being eaten by the ants it feeds on?
The Great Plains narrowmouth toad produces distasteful skin secretions that help deter many potential predators, including the ants and termites themselves, from mounting an effective defense or counterattack while the toad is actively feeding on their colony.
Where does the Great Plains narrowmouth toad live?
The Great Plains narrowmouth toad is native to grassland and prairie habitat across much of the central United States, spending much of its time burrowed underground and emerging mainly during humid conditions or to breed in temporary water.