03/16/11

What's the Difference Between a Frog and a Toad?

illustration copyright Arnold Lobel

Ever wonder what the difference is between a frog and a toad? At FROGS ARE GREEN, we thought we’d enlighten you so that when you’re hiking in the woods and someone says, “Look at that cute frog!” you’ll be able to say, “That’s not a frog, that’s a toad!”

Frogs and toads are both amphibians in the order Anura.  Of the three major classifications of amphibians, frogs make up the vast majority, about 90 percent of all amphibian species (the other types of amphibians are salamanders and caecilians). Toads are a sub-classification of frogs, meaning that all toads are frogs, but not all frogs are toads (clear so far?).

WHERE DO FROGS AND TOADS LIVE

Both frogs and toads live near ponds, swamps, and marshes. Frogs can live on the ground or in trees. But toads live only on the ground.

SLIM VS. CHUBBY

Both frogs and toads have stubby front legs and they are both about the same size. But frogs have slimmer bodies and longer hind legs. These limbs are especially good for leaping from tree to tree and for swimming.

Toads are chubbier than frogs. They have shorter hind legs, good for hopping around on the ground, or walking and crawling. They are a bit slower and less active than their leaping frog cousins.

WEBBED FEET OR NOT?

Frogs usually have webbed hind feet, and some have webbed front feet. Some frogs, such as tree frogs, have pads on their toes that help frogs climb trees, or even stick to a glass window.

Most toads don’t have webbed feet or sticky toe pads. They move by a series of short hops on land.

SMOOTH VS. WARTY

Frog skin is usually smooth and moist. Toad skin is drier and bumpier. The bumps look like warts and its skin feels rough (don’t worry—you won’t get warts if you touch a toad’s skin!).

FROG AND TOAD EGGS

Frogs lay eggs in bunches, or clusters, which have a jelly-like substance around them. Toads lay their eggs in lines, or strands, on leaves of plants that live in the water.

These are the basic differences between frogs and toads, but things do get confusing. You can’t necessarily go by the common name of the frog or toad. In some parts of the world, especially tropical areas near the equator, frogs and toads often look alike. For example, the Harlequin frog is actually a toad. The only way to tell these frogs and toads apart is to look at the differences in their teeth and bones. Also, if a frog-like amphibian lives in a dry area, it is most likely a toad.

But for the most part, these guidelines will help you distinguish between the two types of amphibians. So this summer get your camera, your notebook, and binoculars and see if you can find some of these intriguing animals in the woods, near marshes and ponds, or even in your backyard.

10/12/10

The 10 Weirdest and Most Unusual Frogs on Earth

You might be familiar only with the green frogs or brown toads that live in nearby ponds or woods. But frogs and toads are among the most incredibly diverse animals on earth. Here are just a few of the weirdest and most unusual frogs and toads:

Tomato frog (D. antongilli)

Tomato frog, photo courtesy of Charles Paddock Zoo, Atascadero, CA

This frog is definitely NOT green! Colored as red a ketchup, the Tomato frog’s bright color is meant to warn predators that it is not safe to eat.  The frogs secrete a gummy substance that gets in a predator’s eyes so it will drop the frog, which can then make a quick escape.  The Tomato frog is found only in Madagascar.

Glass frogs (family, centrolenidae)

Glass frog. Image courtesy of iFrog.

Glass frogs are nocturnal tree frogs that live in the humid forests of Central and South America. Their name comes from the translucent skin on the underside of their bodies. In many species the glass frogs’ internal organs, even a beating heart, can be seen. This see-through skin helps them blend into the forest.

Ornate horned frog (Ceratophrys ornata)

Ornate horned toad. Image copyright American Museum of Natural History.

This frog is nicknamed the Pac-Man frog because of its enormous mouth and insatiable appetite. They are a sit-and-wait ambush predator and hide well-disguised on the ground or in leaf litter. Ornate horned frogs can swallow birds, insects, mice, or even other frogs whole. This species can be found in Uruguay, Argentina, and Brazil.

Turtle frog (Myobattachus gouldii)

Turtle frog. Photo by Evan Pickett. All rights reserved.

This unusual-looking frog looks like a turtle that has lost its shell. It has a short, blunt snout, little beady eyes, and short, fat limbs. It lives underground in burrows in sandy soil and chambers in termite colonies, upon which it feeds. During a few rainy nights in summer they emerge, mate, then then burrow underground where the eggs are laid. Four to six months later the eggs hatch as fully formed froglets. The Turtle frog only lives in the coastal plains and woodlands of extreme Southwestern Australia.

Wallace’s Flying Frog (Rhacophorus nigropalmatus)

Wallace's flying frog. Image copyright Tim Laman, National Geographic.

These frogs leap and glide from tree to tree by spreading out their huge webbed feet like parachutes.They are rarely found on ground except to mate and lay eggs. Their oversized toe pads help them stick to tree trunks and to land softly.  Flying frogs inhabit the dense tropical jungles of Malaysia and Borneo.

Water-holding frog (Cyclorana platycephala)

Unusual among frogs, water-holding frogs can catch prey—aquatic insects and small fish—underwater, lunging at the animals and stuffing them in their mouths with their arms. During the dry season they become inactive and burrow underground, secreting a mucous to line their burrows. This hardens around the body and enables the frog to retain water that might otherwise be lost due to evaporation. These frogs were traditionally used by indigenous people in Australia as a source of water. They would dig up the frogs, gently squeeze the water from them, and release them unharmed. Water-holding frogs live in grasslands, temporary swamps, and clay pans in arid areas of southern Australia.

Pinocchio-nose frog (no scientific name yet)

Pinocchio-nosed frog courtesy of Treehugger.com

The Pinocchio-nosed frog was discovered recently during a wildlife expedition to Indonesia’s remote Foja Mountains. This long-nosed frog, a tree frog, has a spike on its nose that points upward when the male is calling but deflates and points downward when he is less active. You can see the Pinocchio-frog and the other newly discovered species on the National Geographic site.

The hip pocket frog (Assa darlingtoni)

Hip Pocket Frog courtesy frogs.org.au

This is called a Male Marsupial frog because like a kangaroo it carries its young in pouches. It has two openings, one on each hip, where tadpoles develop. First the female lays eggs in damp sand, then they are guarded by the male, and finally they hatch into finless white tadpoles, which wriggle their way into the pouches. Only about half make it. They emerge 7 to 10 weeks later as froglets. Hip-pocket frogs are terrestrial and live among leaf litter in the forest (and like a few of our other unusual frogs, they are only found in Australia).

Southern gastric-brooding frog (Rheobatrachus silus)

Gastric brooding frog

This species was discovered in 1972 living in rocky creeks and ponds in the rainforest of Queensland, Australia. They have an amazing way of “bringing up baby.” First the female swallows her eggs, then her digestion slows down and she stops feeding and the tadpole develops in her stomach. After six to eight weeks, she opens her mouth, dilates her esophagus and the babies crawl out. Sadly, this extraordinary frog is most probably extinct. The last wild southern gastric-brooding frog was seen in 1981—the last known frog in captivity died in 1983.

Pipa or Surinam Toad (Pipa pipa)

Surinam toad

This Surinam toad is the world’s flattest amphibian—in fact, it looks like the victim of an unfortunate road accident. Yet this frog’s unusual shape helps hide it among the leaves and plant debris in the streams they inhabit in the Amazon River Basin of South America. Like some of the other frogs above, they have an amazing reproductive strategy: after the female lays eggs the male attaches them to the female’s back. They stick to her skin, which grows to form pockets over them, giving her a honeycomb appearance. The tadpoles grow within these pockets and emerge as toadlets after 20 weeks.

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We’ve designed a cool new 2011 calendar and poster: The Weirdest and Most Unusual Frogs on Earth. Get one for your kid’s room!

Note: I got most of the information for this post from The Golden Guide to Frogs and Toads:

Golden Guide to Frogs and Toads by Dave Showler, illustrated by Barry Croucher.

08/18/10

Back to School at FROGS ARE GREEN!

It’s back-to-school time and we’d like to introduce you to a few notable children’s books about frogs and other amphibians published recently:

THE FROG SCIENTIST by Pamela S. Turner, photographs by Andy Comins (Houghton Mifflin, 2009)

Dr. Tyrone Hayes, with his children, reads a book his mother gave him as a child, from THE FROG SCIENTIST. Photo copyright Andy Comins.

This book, part of the Scientist in the Field Series, is a biography of frog scientist Dr. Tyrone Hayes at UC-Berkeley, who has done groundbreaking studies about the effects of atrazine, a widely used herbicide, on frogs.  While the book is mainly a biography of Hayes, it is also a good overview of the global amphibian crisis and it includes an easy-to-understand explanation of the scientific method. The book has a lively, engaging design and many wonderful photos. It would be ideal for kids who are at that age (around 10 or so) when they decide that “science is boring.”

Dr. Hayes is an engaging subject for a biography, and the anecdotes about him are refreshing for this type of book (which can often be dry). A whole unit could be planned around THE FROG SCIENTIST, covering such topics as a science as a career, African Americans in science, the global amphibian decline, the scientific method, to name just a few.

A PLACE FOR FROGS by Melissa Stewart, illustrated by Higgins Ford (Peachtree 2009).

A PLACE FOR FROGS by Melissa Stewart, illustrated by Higgins Bond

For younger children (@5-8), this nonfiction picture book introduces different species of frogs and places them in their habitats. Each oversized double-page spread features a frogs species, their habitat, and shows some of the ways that human action and interaction can affect frog populations.

For example, one spread describes the Sierra Nevada Yellow-legged frog and its habitat, and explains why adding trout to the frogs ponds caused their decline (the trouts devoured the tadpoles). When people removed the trout, the frog populations began to recover. The frog and its habitat is depicted in gorgeous realistic paintings and is described in easy-to-understand language.

A Place for Frogs could be used for teaching kids about animal habitats (this author/artist team also did A Place for Butterflies and A Place for Birds). It could also be used in a unit about endangered animals, a unit devoted to frogs and amphibians, or it could be read as a springboard to study a local endangered frog in more detail, depending on where the school is located.

Big Night for Salamanders by Sarah Marwil Lamstein, art by Carol Benioff (Boyds Mill, 2010).

Illustration from BIG NIGHT FOR SALAMANDERS by Sarah Marwil Lamstein, art by Carol Benioff

In this narrative nonfiction picture book, a boy waits for the Big Night, the first rainy night in late winter or early spring when the blue-spotted salamanders begin their annual migrations. The salamanders must travel from their forest burrows to vernal pools, where they breed and lay eggs. The problem is the salamanders must cross a busy highway to reach the vernal pools. The boy, along with other volunteers, helps the salamanders cross the road. A parallel text in italics describes the migration of salamanders.

This is a lovely simple story about how one boy helps an endangered species close to home. It is illustrated in richly-colored gouache. At the back is information about the life cycle of blue-spotted salamanders, as well as information about the Big Night and vernal pools.

Big Night for Salamanders would be a good read-aloud book for younger children. It could also be used in units about the life cycles of animals, and about species whose habitats are threatened. Teachers could read this book in the spring and plan a field trip to a local vernal pool.

Don’t forget about the FROGS ARE GREEN ART CONTEST FOR KIDS! Please download and print out this flyer to tell kids about the contest.