The San Diego Zoo’s first amphibian, a giant marine toad, joined our collection in 1933. It was taken from a hollow log in a Central American jungle by the Zoo’s first professional herpetologist, C.B. Perkins. In 1968, a reptile and amphibian exhibit was opened, dedicated to Laurence Klauber, the Zoo’s first reptile curator.
Today, visitors to the San Diego Zoo can see some of the many frogs and toads in our remarkable collection in our Reptile House and in our new Reptile Walk. They include Panamanian golden frogs, poison frogs, smooth-sided toads, tomato frogs, and Surinam toads. We care for more than 280 individual amphibians that represent 27 different species. Some of the threatened and endangered species we’ve bred here are tomato frogs, golden mantellas, and mountain yellow-legged frogs. We also work with some unusual species that are not endangered but provide us with valuable experience in caring for and raising frogs, including Bornean eared frogs, Surinam toads, and mossy tree frogs.
At the San Diego Zoo Safari Park, you’ll find some African frog species in our Hidden Jungle habitat. And you can meet an African bullfrog or White’s tree frog up close, with the help of a naturalist, at our new Nairobi Station. Hop to it!
Hear from the experts! Read our Reptile & Amphibian blog.
The world is currently facing an amphibian extinction crisis, with 33 percent of the world’s amphibians threatened with extinction. In the 1980s, scientists began getting reports from all over the world about disappearing amphibian populations, even in protected areas! Amphibian extinctions are alarming, as these animals play a critical role in their ecosystems. For example, imagine what could happen if frogs weren’t around to eat insects!
The loss of wetlands and other frog habitat because of industry and human population growth is one of the biggest causes of amphibian decline. The increase of roads has been hard on migrating frogs, too. When frogs try to cross a highway to get to their breeding pools, cars squash many of them. Nonnative species like trout and even other frogs that humans introduce often eat all the native frogs. There are also pollutants that get into the rivers and ponds and kill the frogs and tadpoles.
An emerging disease called chytrid fungus is causing severe declines in many frog populations. The fungus lives in water, so frogs are easily infected, and it covers their thin skin so the frog can’t breathe or get water. It also affects larvae and tadpoles, growing on their mouth parts and preventing them from eating. But its impact is not limited to wild frogs, because maintaining healthy zoo populations is also essential for conservation programs. Captive amphibians that are free of disease have a much higher survival rate and have less risk of exposing wild populations to disease during reintroduction efforts.
San Diego Zoo Global has long supported the Panama Amphibian Rescue and Conservation Project to save frogs through biosecurity consultation and education, providing disease testing to over 80 zoos nationwide. We have developed disease-control guidelines for a variety of endangered amphibians, including the Kihansi spray toad, a species from Tanzania that currently exists only in zoos. In Central and South America, 60 amphibian species have been rescued and are being maintained in safe survival-assurance colonies until a time when it is safe to return them to their habitat. Twelve of the most at-risk species have now reproduced in managed care, including the horned marsupial frog, crowned tree frog, and Limos harlequin frog.
In Ecuador, which is third only to Colombia and Brazil for having the greatest number of amphibian species, an amphibian conservation program called Balsa de los Sapos (Life Raft of the Frogs) is now establishing breeding colonies for safekeeping, creating assurance colonies as a safety net for vulnerable frog species. San Diego Zoo Global works with its staff to help keep this valuable population of amphibians healthy and sustainable by providing disease-screening services. Assisting in coordination of activities and providing educational resources is the Amphibian Ark, a joint effort of the World Association of Zoos and Aquariums and the International Union for Conservation of Nature.
Closer to home, and once abundant in the mountain ranges of Southern California, the mountain yellow-legged frog Rana muscosa is now critically endangered. Multiple factors have contributed to the decline of the species, including habitat loss, drought, introduced predators, pollution, and chytridiomycosis. San Diego Zoo Global is working to restore the ecosystem balance in the San Jacinto Mountains through our captive-breeding and reintroduction efforts for the mountain yellow-legged frog. Since 2010, we have successfully reintroduced zoo-bred mountain yellow-legged frog tadpoles into the wild at Hall Canyon on the University of California’s James San Jacinto Mountains Reserve, where the frogs had been extinct for more than 40 years. Radio transmitters in frog-sized backpacks have revealed a healthy 95-percent survival rate the first month and are now breeding in the wild!
This effort required the collaboration of many groups, including the U.S. Forest Service, U.S. Fish and Wildlife Service, California Department of Fish and Game, U.S. Geological Survey, and the University of California Natural Reserve System. The ultimate goal of this project is to reestablish stable populations of mountain yellow-legged frogs in their historic range, the mountain streams of southern California.
We’re also gearing up to establish and freeze amphibian cell cultures in our Frozen Zoo® to help conserve the genetic diversity of frog and toad species. We’re hoping to team up with other zoos and field researchers to collect additional amphibian samples to increase our genome bank.
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, watch your favorite animal television show, or visit the San Diego Zoo to discover how great amphibians are. Prime amphibian real estate includes hiding places like leaf litter, rocks, and logs, a source of clean water, and insects to eat. Creating a well-kept and water-wise backyard pond makes a great family project! Do your part to keep garbage, chemicals, and nonnative plants and animals out of the natural environment to protect amphibian species from pollution and predation. Discourage your canine and feline family members from pestering wildlife. Curious cats and digging dogs cause a lot of stress for frightened amphibians. If you come across an amphibian, look, listen, and leave it where it is!