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In A Frog’s World
Step into the world of writers and photographers as they tell you about the best, worst, and quirkiest places and adventures they encountered in the field.

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Frogs Habitat

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By Virginia Morell Photographs by George Grall

Victims of pollution, disease, and habitat loss, amphibians are vanishing all over the globe.

Get a taste of what awaits you in print from this compelling excerpt.

In many frog species the males protect the eggs. In South America male Darwin’s frogs slurp up the fertilized eggs and hold them in their vocal sacs until the froglets emerge. In other species females provide the parental care. The female Surinam toad (Pipa pipa), an aquatic species, converts her entire back to a nursery. She and the male swim end over end in their mating dance, transferring the fertilized eggs to pouches in her back. Her skin grows over the eggs, sealing them in until the froglets hatch.

As wonderful as these adaptations are, none is—or was—as remarkable as that of Australia’s gastric-brooding frogs, Rheobatrachus. Researchers invariably mention the two species in this genus as the most astonishing example of what frogs can do. The females of this two-inch-long (five-centimeter-long) stream dweller swallowed their fertilized eggs or tadpoles, shut down their digestive systems, and hatched their young in their stomachs. About a month later the mother opened her mouth and regurgitated her tiny froglets.

“It was almost unbelievable,” says Keith McDonald, the chief ranger with the Queensland Parks and Wildlife Service. “You could see the little buggers pushing their tiny hands and feet inside their mum’s swollen belly.”

Stocky and pink-faced, with a twinkle in his blue eyes, McDonald had helped monitor the two known populations of gastric brooders shortly after they were first discovered about 25 years ago. “Then bang! They disappeared in the blink of an eye. Ahhh, how can I describe my feelings?” he says, his voice cracking and his eyes misting up. “I’d been watching this population; I went back three months later, and that’s when it hit me in the guts.” McDonald recalls walking frantically up and down the stream, turning over rocks, searching for frogs. None were to be found. No one has seen a gastric brooder in the wild since the 1980s, and none are in captivity; they are apparently extinct.

But the gastric brooders aren’t the only species of frogs to have vanished or fallen on hard times. Since the 1970s more than a dozen Queensland frog species, especially the stream-dwelling types, have experienced sudden, massive die-offs. At the same time many frog populations in protected areas of Central and South America and the western United States also plummeted. In some cases, such as in these remote Queensland mountains, certain frog populations vanished in a few short months.

Other frog species in the U.S. West and Midwest began turning up with deformities, particularly misshapen or extra hind limbs, in disturbing numbers. Though no evidence suggested a link between the outbreak of deformities and the die-offs, this much was clear: Something in the environment was adversely affecting frogs, but no one was certain what it was or how many factors were to blame.

Get the whole story in the pages of National Geographic magazine.

VIDEO Photographer George Grall talks about getting up close and personal with frogs.

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Frogs may signal that something’s wrong in the environment. How can we expand our knowledge of poorly researched areas before frogs and other key species disappear?
Join the discussion.

Final Edit
The one that got away from our coverage of frogs is this month’s Final Edit.

Point of View
Grall reveals the techniques used to get two of his most astounding frog photos.

In More to Explore the National Geographic magazine team shares some of its best sources and other information. Special thanks to the Research Division.

Some frogs and toads have poisonous substances in their skin and can be deadly if touched or eaten by predators—or curious explorers. In National Geographic magazine’s May 2001 story about frogs, there is a picture of biologist Karen Lips holding a poisonous frog in her hand. How can she touch such a dangerous animal? This particular species, the Panamanian golden frog (Atelopus zeteki), could be fatal if it was eaten by a small predator. However, its bright color serves as a warning to predators like snakes or birds to stay away. For a human, the frog’s toxic secretions are a painful irritant but do not cause permanent damage. “We try to remember not to touch our eyes or put our hands in our mouths after handling all frogs,” says Jeanne Robertson, Dr. Lips’s graduate student assistant, “but it is not an issue.” Most importantly, no one who is not a trained scientist should handle the Panamanian golden frog because it is an endangered species. It is illegal to keep, collect, or export this animal. If you’re fortunate enough to see one in the wild, enjoy its beauty from a distance.

—Robin Adler

Vanishing Frogs
From the tundra to the tropics, frogs are vanishing the world over. Why? Who are some of the victims? What can you do to help? Find out in this special feature produced by National Geographic senior text editor Carol Lutyk and students at Arizona State University in Tempe.

Declining Amphibians Population Task Force (DAPTF)
The DAPTF home page provides a wealth of information about amphibian declines worldwide. Factsheets on the site discuss possible causes of declines, explain why we should care about the disappearing amphibians, and showcase the task force’s work. The DAPTF is a network of over 3,000 scientists and conservationists from more than 90 countries around the world.

Frogwatch USA
Find out how to look for and study wild frogs and toads, discover which frogs and toads live in your part of the country, and sign up to become a volunteer for FrogWatch! This monitoring program depends on volunteers to help collect information about frogs and toads from across the country. The program is coordinated by the U.S. Geological Survey Patuxent Wildlife Research Center.

The Amphibian Decline Phenomenon
This site offers more than 25 possible causes of amphibian die-offs and deformities (such as drought, habitat loss, and the pet trade), and links to numerous other sites on the subject.

Comprehensive database providing taxonomic information about amphibian species worldwide. Searchable by scientific or common name. Search results provide links to museums that hold specimens of these species.

Amphibian Photo Search Page
Part of Amphibiaweb (see above), this searchable database helps you find pictures of some species of amphibians. You can search by scientific name, common name, location, or photographer.

What Is the Frog Chytrid?
A good source for scientific information about the chytrid fungus that is afflicting frogs throughout the world. Includes a bibliography.


Badger, David. Frogs. Voyageur Press, 1995.

Barker, John and others. A Field Guide to Australian Frogs. Surrey Beatty & Sons, 1995.

Blaustein, Andrew R., and David B. Wake. “The Puzzle of Declining Amphibian Populations,” Scientific American (April 1995), 52-57.

Duellman, William E., and Linda Trueb. Biology of Amphibians. Johns Hopkins University Press, 1986.

Phillips, Kathryn. Tracking the Vanishing Frogs: An Ecological Mystery. Penguin Books, 1994.

Souder, William. A Plague of Frogs: The Horrifying True Story. Hyperion, 2000.


Hill, Carolinda. “What’s the Difference?” National Geographic World (March 1998), 16-18.

Moffett, Mark W. “Poison-Dart Frogs: Lurid and Lethal,” National Geographic (May 1995), 98-111.

Miller, Charles. “Life Around a Lily Pad,” National Geographic (January 1980), 131-142.

Zahl, Paul A. “In Quest of the World’s Largest Frog,” National Geographic (July 1967), 146-152.

Davidson, Treat. “Bullfrog Ballet Filmed in Flight,” National Geographic (June 1963), 791-799.

Zahl, Paul A. “In the Wilds of a City Parlor,” National Geographic (November 1954), 645-672.

Cochran, Doris M. “Our Friend the Frog,” National Geographic (May 1932), 628-654.


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