Frogs and toads... the rise of the amphibian crisis

argentine horned frog FACT SHEET

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GlossAry of terms:

AZA: Association of Zoos and Aquariums - The Louisville Zoo is a member of the Association of Zoos and Aquariums (AZA), an organization that represents and accredits professionally managed zoos and aquariums in North America. For more information on AZA, visit www.aza.org.

Bioindicator: An organism that is used to describe the quality of the ecosystem.

Caecilians: A group of amphibians that look like large worms or slick snakes and do not have arms or legs.

Devonian Period: Started about 405 million until 345 million years ago. This period had a prevalence of fishes and included the appearance of amphibians and ammonites.

Dual Life Cycle: An ability to exploit both aquatic and terrestrial habitats

Ecosystem: A system formed by the interaction of a community of organisms with their environment.

Ectotherm: An organism whose body temperature is determined by the temperature of the environment, “cold-blooded.”

Endangered Species: A species at risk of extinction because of human activity, changes in climate, changes in predator-prey ratios, etc., esp. when officially designated as such by a governmental agency such as the U.S. Fish and Wildlife Service.

Invertebrates: Animals lacking a backbone or spinal column.

Metamorphosis: A process where amphibians undergo a dramatic change in anatomy, diet and lifestyle. During this time, amphibian larvae slowly change from fishlike, water-dwelling animals to animals better suited for life on land. In addition to developing lungs, salamanders and frogs grow limbs during metamorphosis. Most amphibians lose their gills, and the tails of frogs and toads disappear. The length of time required for metamorphosis varies widely among different species.

Newts: A family of salamanders that generally possess a rough skin. .

Permeable skin: Skin that allows substances (chemicals, pollutants, etc) to move freely into it.

Salamander: A name for an entire group, or scientific order, of amphibians that have tails as adults, and includes animals commonly known as newts and sirens.

Species Survival Plan (SSP): The Species Survival Plan or SSP is the AZA’s cooperative breeding and conservation program. It is the cornerstone of efforts to assist endangered species.  Institutions that agree to participate in SSP programs agree to manage their animals in the best interest of the species. Each SSP manages the breeding of a species in order to maintain a healthy, self-sustaining captive population that is both genetically diverse and demographically stable.   In addition, SSPs involve research, public education and field projects.  Click here to see which animals are currently on a SSP list at the Louisville Zoo, visit.

Vertebrates: Animals that have a backbone or spinal column.

Frequently Asked Questions

What is an amphibian?

Amphibians live part of their lives in water and part on land. They are separated into three groups:

1. salamanders and newts

2. frogs and toads

3. caecilians

Amphibians are vertebrates and ectothermic, too. This means they cannot regulate their own body temperature and must rely on their surroundings to either warm or cool themselves. If they need warmth, they will go into the sunlight. To cool their bodies, they must find a burrow or some other type of shade. Amphibians are most active when warm and tend to be sluggish in the cold.

Amphibians lay their eggs in water. When the eggs hatch they will have gills and breathe their oxygen from water like fish. As they develop, their body shape, diet, and lifestyle will go through a metamorphosis. During this stage, they will develop lungs and legs to live on land.

Amphibians have sensitive skin. Most have soft, moist skin that is protected by slippery secretion mucus. Their bodies can easily dry out which is why they are generally found near water or moist places.  Amphibians use their skin to help them breath. This is a main reason why they have become threatened—they absorb negative environmental changes like pollution and pesticides.

How many amphibian species are there?

It is believed that there are more than 6,000 amphibian species on the Earth.

What frog and toad species do you have at the Louisville Zoo and where are they located?

There are currently are about 17 species of frogs and toads at the Louisville Zoo. They include:

• African bullfrog

  • And a six-legged American bullfrog

• Argentine horned frogs

• Clawed frogs

• Colorado River toads

• Cuban treefrogs

• Fired-bellied toads

• Fowler’s toads

• Gray treefrogs

• Green treefrogs

• Panamanian golden frogs (Endangered)

• Poison-dart frogs (two species)

• Puerto Rican crested toads (Endangered)

• Smoky jungle frogs

• Squirrel treefrogs

• Tomato frogs

• White’s treefrogs

• We also have salamanders, ranging from the giant hellbender and amphiuma, to small newts.

They are located in the HerpAquarium and the MetaZoo Education Center.

What is the importance of amphibians?

The importance of amphibians should be viewed in a wide context. Louisville Zoo’s Curator of Ectotherms Bill McMahan has noted that amphibians have been on Earth a long time (since the Devonian Period) but many species are now in trouble, with about one-third of Earth’s 6,000 amphibian species deemed vulnerable to extinction.

Frogs and toads play an important role in Earth’s ecosystems—not only do they help control insect populations, they are also food themselves for many animals.

Amphibians also act as a “barometer” for the health of various ecosystems because their sensitive and permeable skin makes them one of the first species to react to any kind of contaminant or changes in the environment. This makes them a good indicator of the ways environmental contamination and other factors impact aspects of the ecosystem.

Why are amphibians globally declining?

According to the Louisville Zoo’s Curator of Ectotherms Bill McMahan, many theories have been put forth for the demise of several amphibian species, and they include:

• Thinning of Earth’s ozone layer and increased levels of ultraviolet radiation (which also causes skin cancer in humans)

• Widespread use of pesticides and herbicides (which can also have adverse effects on humans)

• Habitat destruction

• Pollution of our waterways (another concern to humans)

• Climate change

• The rapid spread of a chytrid fungus that destroys the skin of amphibians has been transported into regions where native amphibians have no resistance. The chytrid fungus is a disease that prevents amphibians from being able to breathe through their skins. The disease has appeared on many amphibians throughout Australia, Central and South America, Europe and the United States.

	Source: Global Amphibian Assessment
	click on map for larger image

So, there is an “Amphibian Crisis” going on worldwide?

Yes, there is an amphibian crisis going on. According to Global Amphibian Assessment, nearly 32 percent of the world’s amphibian species are considered to be threatened, which means their numbers are declining and they might become extinct. They estimate that 165 amphibian species may already be extinct. Only about 1 percent of the amphibian species show population increase this indicates that the number of threatened species is expected to rise. While the recent fungal disease is a serious factor in the declining species, habitat loss is posing the greatest threat to amphibians at this time.

How can I help protect and save frogs and other amphibians?

The Association of Zoos and Aquariums (AZA) is highlighting 2008 as the Year of the Frog to mark a major conservation effort to address the amphibian extinction crisis. Here are eight ways they suggest you can help frogs in 2008.

1. Look, listen, and learn: educate yourself and your family about amphibians.
   With more than 6,000 frogs, toads, newts, salamanders, and caecilians worldwide, there's a lot to learn. Pick up a book, hop around the Internet, or watch your favorite animal television show to educate yourself and your family about amphibians.

2. Visit the Louisville Zoo (an AZA-accredited institution) and experience your very own amphibian adventure! The Louisville Zoo is a great place to see and learn about amphibians from around the world.

3. Create an amphibian friendly environment in your back yard by providing clean water, hiding places and insects to eat. Prime amphibian real estate includes leaf litter, rocks, logs, and a source of water—backyard ponds make a great family project!

4. Don't pollute. Do your part to keep garbage, pesticides, herbicides and other chemicals, and non-native plants and animals out of the natural environment. Amphibians absorb chemicals through their skin easily. They also fall prey to non-native species. 

5. Be a responsible pet owner. Discourage your canine and feline family members from pestering wildlife, especially amphibians and birds. Curious cats and digging dogs cause a lot of stress for frightened amphibians. If you or your pet encounters an amphibian, study, look, listen and then leave it where it is.

6. Conserve water at home, school and work. Save water by using collected rainwater for watering gardens and potted plants. The water you save now remains a clean habitat for wild amphibians without being chemically treated.

7. Reduce the use of fossil fuels, such as oil, coal and natural gas. Climate change is impacting amphibian populations worldwide. By using less energy or choosing renewable sources of energy, you can help slow the rate of climate change. Drive less, buy fuel-efficient cars, and use compact fluorescent light bulbs!

8. Be an amphibian champion. Make a donation to the Zoo for amphibian conservation. Participate in citizen-science monitoring programs with your family. Be aware of legislation affecting wildlife and their habitat, global warming, and land use and development issues.

How can I find out more information on amphibians?

The Louisville Zoo will be hosting a Party for the Planet Celebration April 6-April 13. It is a nationwide celebration with the Association of Zoos and Aquariums (AZA) to help visitors discover ways to connect to the local environment and make a collective difference in conservation on a national and global level. This year we will celebrate the Year of the Frog during this Spring Break event. A variety of activities will be scheduled throughout the week.  You can check back in February for more details. Come join the fun and learn what you can do to help save our planet.

You can also check out these links:

• Anxious About Amphibians! by Doug McCoy, originally published in the Spring 2007 issue of Trunkline Magazine

• “A Silent Spring Revisited” by Bill McMahan, originally published in the Spring 2007 issue of Trunkline Magazine

• 2007-2008 Backyard Action Hero booklet

• http://www.globalamphibians.org/index.html

• http://www.amphibianark.org/finalhome.htm

• http://www.amphibians.org./

• http://www.savethefrog.com/

PHOTOS

Poison Dart Frog (photo by Will Bird)

Tomato Frogs (photo by William Quatman)

Panamanian Golden Frog (photo by Will Bird)

Clawed Frog (photo by Will Bird)

Argentine Horned Frog (photo by Kara Bussabarger)

Spotted salamander (photo by Will Bird)

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Poison Dart Frog (photo by Will Bird)

LOUISVILLE ZOO  *  1100 TREVILIAN WAY, LOUISVILLE KY  40213

BETTERING THE BOND BETWEEN PEOPLE AND THE PLANET