Mexican Burrowing Toad Facts, Pictures, Video & In-depth Information: Discover A Unique Central American Amphibian

Mexican burrowing toad facts, pictures & in-depth information. Although fairly common in its range, the Mexican burrowing toad is heard more often than it is seen … groups of calling Mexican burrowing toads can be heard over half a mile (1 km) away!

Mexican burrowing toad
Photo by Greg Schechter from San Francisco, USA (Mexican burrowing toad) [CC BY 2.0]
This distinctive Central American amphibian has a number of adaptations both for burrowing and for eating its preferred prey of ants and termites. It is the only frog in the world that can extend its tongue straight forward rather than flicking it out.

Just listen to its amazing call …

Let’s find out more about this awesome amphibian …

Mexican Burrowing Toad Facts At A Glance

  • Other Name(s): Mexican burrowing frog, Burrowing toad, cone-nosed frog
  • Scientific name: Rhinoprhynus dorsalis
  • Type of Animal: Amphibian
  • Animal Family: Rhinophrhynidae
  • Where Found: Texas, Mexico and Central America
  • Snout-Vent Length: 3 to 8.0 cm (2.5 to 3.2 in)
  • Conservation Status: Least concern

Meet The Mexican Burrowing Toad: Introduction

The Mexican burrowing toad is the only member of the family Rhinophrynidae. The species is genetically distinct and not closely related to any other burrowing frogs.

The name of the genus Rhinoprhynus is derived from Ancient Greek and means ‘nose-toad’.


Frog Vs Toad

Both frogs and toads are in the same order: Anura. Although frogs with warty skin are commonly known as ‘toads’, this is an informal definition. Biologists tend to consider all anurans (members of the order Anura) to be frogs.


What Does The Mexican Burrowing Toad Look Like?

Mexican burrowing frog
The Mexican burrowing toad has a distinctive flat body and colourful markings. Photo by Greg Schechter from San Francisco, USA (Mexican burrowing toad) [CC BY 2.0]
The Mexican burrowing toad has a distinctive appearance, and can’t easily be confused with any other species. Its colorfully-marked body is covered in loose-fitting, wrinkled skin. When the frog makes its distinctive call, its body swells up like a balloon and the skin becomes taut and shiny.

The Mexican burrowing toad’s body is flat and almost as wide as it is long. The head is small and triangular. The snout is covered with tubercles (small bumpy outgrowths). The eyes are widely-spaced and have vertical pupils. There are no visible tympani (eardrums) behind the eyes.

The Mexican burrowing toad’s legs are short and muscular – more suited to burrowing than to moving over the ground. There is only a trace of webbing between the digits of the front limbs. The webbing is extensive between the toes of each hind foot.

The frog’s feet are equipped with short spade-like appendages which are reinforced with keratin – the same hard material out of which our nails are made. This is an adaptation for the frog’s burrowing lifestyle.

The frog’s skin ranges in color from dark brown to almost black. A bright red or orange central stripe runs along the length of the frog’s back. The frog is also marked with numerous other blotches and spots which are the same color as the central stripe.

The frog’s undersides are usually gray to dark brown in color, and either sparsely-marked or not marked at all.

Female Mexican burrowing toads are larger than the males.

Here’s more footage of that amazing mating call …

Tadpoles

Like most amphibians, the Mexican burrowing frog begins life in a larval stage (frog larvae are known as tadpoles) before metamorphosing (changing) into its adult form.

Mexican burrowing toad tadpoles have broad, flat heads with small eyes and wide mouths. The tail is roughly 1.5 times the length of their body. The coloration is generally dark gray or black with an iridescent silver underside.

Where Is The Mexican Burrowing Toad Found?

The Mexican burrowing toad is found in coastal areas of Central America and Mexico. The species is also present in southern Texas – the only US state in which the species is found.

The species’ range (i.e. the area in which it is found) extends south from Texas to Guatemala on the west coast of the peninsula (the Atlantic slope).

On the east coast (the Pacific slope), the frog is found from the state of Guerrero in Mexico southwards to Costa Rica.

You can find these areas on the map below:

Habitat

The Mexican burrowing toad inhabits a variety of coastal habitats. The species is strongly associated with seasonally flooded habitats. It occurs in tropical forests, savannas, scrubland, fields, gardens and cultivated areas at elevations up to 500 m above sea level.

The most important habitat requirement for the species is soil that is easily crumbled and therefore suitable for burrowing in.

Behavior

As its name suggests, the Mexican burrowing toad is a fossorial (burrowing) animal. It spends most of the year hidden underground in a self-made burrow, only emerging after prolonged heavy rain.

The frog is able to survive lengthy periods of drought inside its underground burrow. A captive individual was reported to have survived for 18 months without feeding.

The Mexican burrowing toad is nocturnal (active at night).

Vocalization

The call of the Mexican burrowing toad is as distinct as the animal’s physical appearance. The male frogs emit a loud, low-pitched ‘Whoooo’ sound. Each note lasts around 1.4 seconds and is repeated roughly 15 to 20 times per minute.

When the frog is alarmed or vocalizing (calling), its body becomes grossly inflated and resembles a balloon, with the head and the limbs almost concealed.

Mexican Burrowing Toad Life Cycle

After periods of heavy rainfall, the Mexican burrowing toad emerges from its underground burrow in order to mate. This may occur at any time of the year, but usually takes place at the beginning of the rainy season in summer.

The male frogs aggregate in large numbers to form ‘choruses’. Choruses take place in or near temporary bodies of water, including roadside ditches and flooded pastures.

The frogs may travel up to 1.6 km (1.0 mi) to find a suitable spot.

Mating takes place either on the surface of the water or on soil near the water. After mating the female lays several thousand eggs into the water. The eggs are laid in small clumps which quickly separate and sink to the bottom. The eggs hatch in just a few days.

The tadpoles form shoals which contain from 50 to several hundred individuals. The shoals have been observed swimming in a coordinated manner.

Mexican burrowing toad tadpoles feed on phytoplankton (microscopic organisms that live in water). The tadpoles develop quickly and metamorphose into their adult form within 1 to 3 months. The speed of development may be dependent on the availability of food.

What Do Mexican Burrowing Toads Eat?

The Mexican burrowing toad is a specialist eater of ants and termites. Its diet also includes a variety of other insects and invertebrates.

The frog has several morphological adaptations for feeding on these small insects, including bumps on its snout which appear to act as armor.

One of the frog’s most unusual adaptations is its tongue, which is unique among frogs.

Whereas most frogs flick their tongues out – either from the back or front of their mouths – the Mexican burrowing toad’s tongue actually changes shape, extending horizontally outwards from the mouth.

The frog is thought to push its head against the side of an ant or termite nest and push its tongue into the nest. The insects are brought back with the tongue as it is withdrawn.

The Mexican burrowing frog is the only known frog to have this type of tongue.

Is The Mexican Burrowing Toad Endangered?

The Mexican burrowing toad is rated ‘Least Concern’ by the IUCN.

The species’ burrowing lifestyle makes determining the size of the population difficult. However, the species is found in a large variety of habitats, has a wide distribution range, and is considered common throughout its range in Mexico and Central America.

The species is considered rare in Texas.


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