Frog or Toad?
By Suzanne Wilson
Here's how to help your Cub Scouts identify a frog or a toad, plus learn more about amphibians.
On a spring day nature ramble, a young, sharp-eyed Cub Scout makes a discovery. “Look at what I found!”
It’s a small, squat creature, with a big mouth, bulgy eyes, no neck, and hind legs that fold up. Its mottled colors blend with its surroundings.
“It’s a frog!”
Another child disagrees: “No, it’s a toad. Can I hold it?”
Which is it? Eyes turn to you. How do you answer?:
(a) “Let’s figure it out. First, is its skin smooth or bumpy?”
(b) “Frog? Toad? You could have fooled me!”
(c) “Um, we could look it up.”
If (a) isn’t likely to be your response, maybe your last science class was too long ago.
Why do frogs and toads especially fascinate children? Well, compared to the average family cat or dog, frogs and toads are small, with strange-feeling skin, globular eyes, interesting toes, and startling hops or leaps. Some have a mouth that almost seems to smile.
Whether we think they’re beautiful or bizarre, watching them is just plain fun.
Wouldn’t it be handy to know some of the differences between frogs and toads? They are all around, in yards, gardens, and wetter, wilder places. And little tree frogs have even shown up in bathroom showers.
Unfortunately, the question is easier asked than answered, because there are no standard differences between the two that apply in every case.
Frogs and toads belong to the class of vertebrates (animals with backbones) called Amphibia, which also includes newts, salamanders, and caecilians (a legless, wormlike amphibian).
The word amphibious comes from the Greek amphibios. Amphi means “both,” and bios means “life.”
If you find a pond or a puddle where tadpoles have hatched, you’ll see the development of hind legs and front legs, the diminishing tail, and then the small froglets or toadlets—if you return before they hop away.
In most frog and toad species, fertilization of eggs is external. The male clings to the female’s back and covers the eggs with sperm as she releases them into water.
As cold-blooded creatures, their body temperature isn’t regulated internally; it stays close to the temperature around them, and they can warm up or cool down by changing locations.
In cold weather, they hibernate. Toads usually burrow into the ground. Frogs seek mud at the bottom of ponds or streams, or they find sheltered moist places on land.
Frogs and toads make up their own order of amphibians called Anura, meaning they have no tails.
When you find a frog or toad, you can point out many observations to young nature students.
There are four “fingers” on the front legs and five “toes” on the hind legs. Note webbing or lack of it.
Spadefoot toads have a sharp, black spade on each hind foot that they use to dig backward into loose sand or soil. Tree frogs’ digits have sticky concave disks like suction cups that hold them to slick, vertical surfaces, even glass.
When a frog or toad is calling, look below the mouth for a pouch expanding like a balloon. A few frog species have one on either side, just behind the head. The sac amplifies the sound made by the vocal cords.
As for ears, all you’ll see are two external eardrums, each a flat circular area behind the eye.
Look for a toad’s paratoid glands, a bump behind each eye. These can give a biting predator a squirt of poison that can lead to muscle spasms and breathing difficulties, as well as future avoidance of the toad. All-over skin secretions of toads and frogs will cause irritation, too.
When they sense danger, frogs and toads inflate their lungs, puffing up their bodies. This can startle a predator, and sometimes an unsuspecting human, too.
Frogs and toads don’t drink water, but their skin takes up or loses moisture as needed and secretes mucous to keep it moist. And though they breathe with their lungs, they also “breathe” through the skin, a process called cutaneous respiration.
Oxygen enters the blood by way of blood vessels close to the skin’s surface, and carbon dioxide is expelled. (Underwater, a frog receives all its oxygen from the water, through its skin.)
Frogs and toads frequently shed their skins and eat them.
What’s for dinner?
Frogs and toads eat almost anything alive that fits in the mouth and smells and tastes right, including insects, spiders, slugs, and earthworms. The South American Ornate Horned Frog can catch a mouse in its huge mouth.
The prey is swallowed whole and alive, because frogs and toads can’t chew their food. Toads have no teeth; frogs have tiny ones for grasping prey.
Toads and frogs have long, folded tongues, hinged at the front of their mouths. When they spy small prey, the sticky tongue flicks out at lightning speed for the catch.
Frogs, with their long, powerful hind legs, make sudden, spectacular leaps for their meals, while toads wait for prey to come within reach before striking.
To learn more
To learn more details and to identify frogs and toads in your region, consult state conservation publications, Web sites, and nonfiction books for children and adults. The Audubon First Field Guide: Amphibians (Scholastic, 1999) is written for children.
A trip to the amphibian collection of a zoo will introduce you to frogs and toads of other regions and countries, including the colorful tree frogs of the tropics.
Children can visit www.nwf.org/frogwatchUSA/ to learn about frogs and toads, hear their calls, and join monitoring programs.
Scientists are investigating declines in numbers of amphibians in many places. Habitat loss and pollution might be reasons, but the numbers have dropped even in some protected and pristine environments.
Climate change, ultraviolet radiation, invasive predators, and diseases are also being studied.
Malformations in amphibians—extra or missing eyes or legs and other deformities— have been reported in 44 states since 1996.
On the Internet, check out Amphibian Declines & Malformations at www.frogweb.gov, a site maintained by the U.S. Geological Survey.
Contributing editor Suzanne Wilson also wrote “Butterfly or Moth?” in Scouting’s January-February 2001 issue. Read it at www.scoutingmagazine.org/issues/0101/a-moth.html.