Amphibians
Crawfish Frog
Lithobates areolatus · also called crayfish frog, gopher frog of the prairie
The crawfish frog is a prairie animal with a very small world. It spends almost its entire life at the mouth of one burrow — a hole a crayfish dug and left behind — and leaves it only for a few frantic nights of breeding each spring.
Overview
Lithobates areolatus lives in the native prairie and pasture of the American Midwest and South. It is a large, stocky, heavily spotted frog, 7–11 cm long. Outside the breeding season it lives down a borrowed crayfish burrow, resting on a mud pad at the entrance and dropping down the shaft when alarmed.
A frog that knows its address
Radio-tracking has shown crawfish frogs returning to the exact same burrow year after year, walking back to it in a straight line after breeding — sometimes over a kilometre.
The snore
Breeding males give a deep, resonant snore so loud that a chorus carries more than a kilometre and a single frog is uncomfortable to hear up close. The frogs migrate to fishless wetlands on the first warm rains of spring, breed over a few nights, and go back underground.
Status
Near Threatened and declining, as native prairie, burrowing crayfish, and seasonal wetlands are all lost. Its close relative, the gopher frog, lives the same way in southeastern pinelands.
Crawfish Frog: common questions
Why does the crawfish frog live in a crayfish burrow?
The tallgrass prairie and pasture it lives in offers almost no natural cover for a frog. There are no forests to shelter in, few rocks, and the ground bakes hard and dry in summer and freezes in winter. Burrowing crayfish solve the problem by digging vertical shafts, often a metre deep, down to the water table, which they then abandon. A crawfish frog takes over one of these, and it gives everything the frog needs — a humid, temperature-stable refuge, protection from predators and fire, and a doorway from which to ambush passing insects. The frog does not dig its own burrow and cannot survive long in the open without one.
How can a frog be that loud?
Crawfish frogs breed in a short, intense window and males compete fiercely to be heard, so the species has evolved an exceptionally powerful call. The male inflates paired vocal sacs on the sides of the throat and produces a low, drawn-out snore that carries across open country far better than a high-pitched call would. Biologists working at breeding wetlands describe the full chorus as physically uncomfortable at close range and audible from more than a kilometre away across quiet farmland. The volume is part of why the species is easier to survey by ear than by sight.
Is it related to the gopher frog?
Yes, closely. The crawfish frog and the gopher frogs of the southeastern United States are near relatives in the same genus, Lithobates, and they share a very similar way of life, spending most of the year down a borrowed burrow and emerging to breed explosively in fishless seasonal ponds. The main difference is the landlord — the gopher frog relies chiefly on gopher tortoise burrows in sandy pinelands, while the crawfish frog relies on crayfish burrows in prairie and pasture. Both are declining for the same underlying reason, the loss of their specific habitat and the burrowing animals that engineer it.
What is being done to save the crawfish frog?
The core need is protecting and restoring blocks of native prairie or well-managed pasture that still have burrowing crayfish, together with the small, fish-free, seasonal wetlands the frogs breed in, and keeping the two close enough that frogs can migrate safely between them without crossing busy roads. Where local populations have crashed, as in Indiana, biologists collect egg masses, raise the tadpoles in captivity past the most vulnerable stage, and release the young frogs, a technique called head-starting, alongside habitat work. Prescribed fire is used to keep the grassland open.