Meet 9 of Panama’s ‘Lost Frogs’

The deadly amphibian chytrid fungus has caused much devastation to Panama’s native frogs, salamanders and caecilians. We have learned a lot about this disease in the last 10 years and we have been able to take stock of its effects. A recent survey of Panamanian frog experts revealed that of Panama’s 214 described amphibian species, about 100 species can still be reliably found even in places where the chytrid fungus is found, and experts consider these species less susceptible to the fungus. Approximately 80 species are very rare, and we simply do not have any idea about their susceptibility to chytridiomycosis, or their current population numbers. 36 species were considered highly susceptible to the chytrid fungus and were once reliably encountered but have experienced, or are predicted to experience, severe chytridiomycosis-related declines.
Unfortunately a number of these species have already completely disappeared in the wild and have not been seen in many years. We call these Panama’s ‘lost frogs’.

1) Atelopus chiriquiensis – Chiriquí harlequin frog
These attractive diurnal frogs were appealing research subjects and occurred in high numbers in highlands on the border of Costa Rica and Panama. There are many scientific papers about this species, and they were primarily studied for their highly toxic tetradotoxins in their skin as well as their unique signaling and aggressive mating behavior. A study by Dr. Karen Lips in the las Tablas reserve of Costa Rica reports that they occurred in high numbers – up to 20 individuals seen in 100m of stream on a single visit, but the frogs experienced a severe chytridiomycosis-related decline over a 5-year period and were last seen in 1996.

A pair of Atelopus chiriquiensis in amplexus. Photo (c) Marcos Guerra, Smithsonian Tropical Research Institute.

A pair of Atelopus chiriquiensis in amplexus. Photo (c) Marcos Guerra, Smithsonian Tropical Research Institute.

2) Atelopus zeteki – Panamanian golden frog
This is Panama’s national amphibian, a charismatic emblem of the environment and conservation. August 14th is a dedicated national day to honor the golden frog as a symbol for Panama’s incredible biodiversity heritage. Recognizing the chytridiomycosis threat, a conservation project called Project Golden Frog established a healthy breeding colony of golden frogs at the Maryland Zoo in Baltimore, another colony is maintained in Panama at the El Valle Amphibian Conservation Center. As predicted, Panamanian golden frogs experienced severe chytridiomycosis-related declines starting in 2006, and the last confirmed observation of Panamanian golden frog in the wild was in 2009. Project Atelopus continues to survey known golden frog sites for survivors, and a detailed conservation plan has been developed by stakeholders and facilitated by the IUCN Species Survival Commission for golden frogs in Panama. The plan aims to eventually reintroduce them to the wild.

One of 2,000 captive Panamanian Golden Frogs managed in captivity by the Golden Frog Species Survival Plan and the Maryland Zoo in Baltimore Photo: Brian Gratwicke Smithsonian Conservation Biology Institute

One of 2,000 captive Panamanian golden frogs managed in captivity by the Golden Frog Species Survival Plan and the Maryland Zoo in Baltimore Photo: (cc) Brian Gratwicke, Smithsonian Conservation Biology Institute

3) Craugastor obesus
This species was found in the spray zone on rocks, boulders in the Atlantic-facing slopes of Western Panama and Costa Rica. The species was last recorded from Costa Rica in 1984 rainforest. This species belongs to the Craugastor rugulosus group and all these closely related species of amphibians have all been have been decimated by the amphibian chytrid fungus.
4) Craugastor punctariolus
This semi aquatic species was found in mountainous streams of Central Panama. Rapid chytridiomycosis-related declines and disappearances were observed in the field in 2004-2008. This species belongs to the Craugastor rugulosus group and all these closely related species of amphibians have been decimated by the amphibian chytrid fungus. Genetic analysis revealed that it is likely a species complex. It has been maintained in captivity, and occasionally deposited eggs that were either infertile or did not develop fully and a viable captive population was not established.

Craugastor punctariolus, Bob's Robber Frog at the El valle Amphibian Conservation Center, photo (c) Kevin Johnson Amph

Craugastor punctariolus, Bob’s Robber Frog at the El Valle Amphibian Conservation Center (EVACC) photo (c) Kevin Johnson Amphibian Ark

5) Craugastor rhyacobatrachus
This species is found in premontane and lower montane southern slopes of the Talamanca Mountains of Costa Rica and western Panama. Despite extensive searches for this species in both Costa Rica and Panama, there are no recent records of this species. This species belongs to the Craugastor rugulosus group and all these closely related species of amphibians have all been have been decimated by the amphibian chytrid fungus.
6) Incilius majordomus
Males of this species were lemon yellow, and females were brown, the only other known toad of this genus that exhibited similar sexual dimorphism was Incilius peringelis—the famous Monte Verde Golden Toad of Costa Rica that is now extinct. Incilius majordomus is known only from the Pacific slope of Cerro Bollo, on the border between the provinces of Bocas del Toro and Chiriquí. This species was described in 2013 using a series of specimens collected in 1980. It has not been seen in the wild since 1980 despite extensive herpetological surveys in the area.

Incilius majordomus type specimen © Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Incilius majordomus type specimen © Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

7) Isthmohyla calypsa
A  treefrog frog covered with spiny tubercles found in a small mountainous area on the border of Costa Rica and Panama where is used to be locally common. At las Tablas in Costa Rica, the species experienced severe chytridiomycosis-related declines between 1993 and 1998. Despite extensive recent survey efforts in Costa Rica and Panama, the species has not been seen recently and is possibly extinct. Many other stream breeding species in this genus have also experienced dramatic declines and are now extremely rare frogs.

1454685426

Isthmohyla calypsa in the wild, Photo (c) Marcos Guerra, Smithsonian Tropical Research Institute.

8) Ecnomiohyla rabborum – Rabbs’ fringe-limbed treefrog
Rabbs’ treefrog is thought to be endemic to the vicinity of El Valle de Anton, where it was always a rare frog difficult to find as they live high in trees and breed in tree holes. Experienced herpetologists could hear their calls reliably at some places, but the last individual was heard in El Valle de Anton in 2008. A few individuals of this species were collected for captive breeding efforts at the El Valle Amphibian Conservation Center and at the Atlanta Botanical Gardens, but captive breeding efforts were unsuccessful. As of 2015 only a single individual persists in captivity at the Atlanta Botanical Gardens.

Ecnomiohyla rabborum - Rabb's Fringe-Limbed Frog at the Atlanta Botanical Gardens. Photo (c) Brad Wilson

Ecnomiohyla rabborum, Rabb’s fringe-limbed  tree frog at the Atlanta Botanical Gardens. Photo (c) Brad Wilson

9) Oophaga speciosa – Splendid poison frog
This large, unmistakable bright red dart frog lives only in the mountains of Western Panama. It was once collected for the pet trade, and was exported as recently as 1992. This species has not been seen in the wild in many years, despite intensive searches. It is not known whether it still lives in captivity, but has probably disappeared from the wild.

Oophaga speciosa, the Splendid poison dart frog. Photo (c) Marcos Guerra, Smithsonian Tropical Research Institute

Oophaga speciosa, the Splendid poison dart frog. Photo (c) Marcos Guerra, Smithsonian Tropical Research Institute

If you have any recent records of these missing species please let us know, and consider uploading your record to the global amphibian bioblitz on inaturalist.

by Brian Gratwicke

*WE ARE SEEKING VOLUNTEERS TO HELP TRANSLATE OCCASIONAL AMPHIBIANRESCUE.ORG WEB PAGES INTO SPANISH, IF YOU ARE WILLING TO HELP US OUT OCCASIONALLY, PLEASE EMAIL Gratwickeb[AT]si.edu FOR MORE INFORMATION.

New Amphibian Study Helps Smithsonian Scientists Prioritize Frogs at Risk of Extinction

graphical abstractScientists at the Smithsonian Institution and partners have published a paper that will help them save Panamanian frog species from extinction due to a deadly fungal disease called Chytridiomycosis (chytrid). The study, which was published Jan. 4 in Animal Conservation, draws on the expertise of amphibian biologists and scientists the Panama Amphibian Rescue and Conservation Project to mathematically determine which frog species have the best probability of escaping extinction with the rescue project’s help.
“We don’t want to arbitrarily decide which species lives and which species don’t, nor do we want to waste our time on species that don’t need our help,” said Brian Gratwicke, co-author on the paper and international coordinator of the rescue project out of the Smithsonian Conservation Biology Institute. “This study took into account the differences in opinions among amphibian experts in Panama and found consensus in a systematic away. This has allowed us to focus on the species where we have the best chance of making a difference.”

The study also found that eight Panamanian species are likely now extinct in the wild due to disease-related declines. About 80 of Panama’s frog species were too rare for conservationists to prioritize their need for help or the likelihood of successful rescue. The new prioritization scheme, however, will allow the scientists to adapt to new information as it becomes available.

“Over the years, several frog populations—and even species—have vanished or nearly vanished from Panama,” said Roberto Ibáñez, the in-country director of the rescue project at the Smithsonian Tropical Research Institute, “Unfortunately, it is impossible to save them all through conservation programs. With this study, we can focus our limited resources on those species that we are more likely to find in the wild and breed in captivity, while we simultaneously look for a way to manage chytrid.”

Since 2009, the rescue project has been building and maintaining insurance populations of frog species susceptible to chytrid, bringing small groups into captivity to breed as the species crashes in the wild. For each of Panama’s 214 known frog species, the paper’s authors asked amphibian experts to determine the probability that: 1) the rescue project could locate an adequate founding population (20 males and 20 females), 2) the rescue project could successfully breed the species and 3) without the rescue project’s help, the species would go extinct.

While most of the rescue project’s original priority species ranked high based on the new prioritization scheme, the conservationists have already started making some changes. They have determined that the likelihood of successfully breeding La Loma tree frogs (Hyloscirtus colymba) is low and they are instead shifting resources to the recently discovered Craugastor evanesco and the Rusty robber frog (Strabomantis bufoniformis), both of which came up as high priorities.

The Panama Amphibian Rescue and Conservation Project is a project partnership between the Cheyenne Mountain Zoo, the Houston Zoo, Zoo New England and Smithsonian Institution.

Update from Project Atelopus: One small frog

There are two types of golden frogs in Panama, Atelopus zeteki, the Panamanian golden frog, and Atelopus varius, the variable harlequin frog, which has more variable coloration ranging from mostly yellow to this darker chevron form. Photo: Jamie Voyles, Project Atelopus

There are two types of golden frogs in Panama. This one, Atelopus varius is the variable harlequin frog, which ranges in appearance from from this browner form to a bright yellow color at some sites. Atelopus zeteki is the distinctive day-glow yellow  Panamanian golden frog. Photo: Jamie Voyles, Project Atelopus

Jamie Voyles

One small frog can offer a great deal of hope. This frog, an adult male Atelopus varius, belongs to a genus that is critically endangered – not a single species, but the entire genus – and it is, therefore, one of the most rare creatures on earth. The Panamanian golden frog Atelopus zeteki carries the additional distinction of being Panama’s national animal and it is a symbol of good luck for the Panamanian people – so much so, that in the past golden frogs graced the face of lottery tickets. So, the loss of Atelopus, due to the lethal disease chytridiomycosis, has been nothing short of a tragedy for Panamanians, as well as for the larger global community.

About a decade ago, together with my colleague, Cori Richards (now Dr. Cori Richards-Zawacki), and I watched these golden jewels vanish from the streams of Panama as the disease chytridiomycosis (“chytrid”) spread across the country. Cori and I were still graduate students; we had a youthful (albeit slightly naïve) enthusiasm for confronting the ominous conservation disaster. Cori focused on golden frogs for her PhD and sampled thousands of frogs before they succumbed to disease. I was interested in understanding which species would be affected by the disease, not knowing that chytrid would, in a few short years, cause a wholesale wipe-out of entire amphibian communities. When frogs started to disappear, our research projects ground to a halt. After all, no frogs means no frog research. So our advisers, perhaps wisely, advised us to move on. As we shifted our research projects to other locales, the golden frogs reached the brink of extinction; sightings of these now-rare creatures dwindled until they were mere rumors.

Jamie_Cori

Drs Cori Richards-Zawaki and Jamie Voyles, the principal investigators of Project Atelopus.

Fast-forward ten years. Cori and I had both advanced in our academic careers, but we were still haunted by the loss of Panamanian amphibians. When Cori visited the University of California, Berkeley, where I was finishing up my post-doctoral work, we spent an afternoon sitting on the green campus lawn and reflecting on our work of a decade earlier; despite the projections, we had not realized the full scope of what had been coming – especially for those beautiful Panamanian  frogs. In those days, we remembered, not very many people outside of a small group of researchers had even heard the word “chytrid”, much less tried to pronounce it. Few were paying attention to the global decline of amphibian populations; even fewer were aware of Panama’s devastating loss of its national mascot and lucky charm. So, naturally, we hatched a plan to return. We needed to see for ourselves what remained of the Panama’s golden frogs.

We set about gathering money from conservation grants, one small award at a time. The news coming from field reports was grim, but we remained determined. We pooled our small pots of funds (including support from the Smithsonian and Project Golden Frog) and galvanized small research team (including Edgardo Griffiths, Heidi Ross and Matt Robak). Soon enough, we trudged the misty mountains of Panama, machetes in hand and hopes held high despite the overwhelming odds. We visited numerous sites where Atelopus varius and Atelopus zeteki were historically found, including all of Cori’s old golden frog sites. We followed rumors, tips and hints. After several months of surveys, after hours of climbing trails with heavy packs and muddy boots, we repeatedly stumbled out of the rainforest disappointed, bug-bitten and empty handed. It would have been easy to admit that we weren’t chasing frogs anymore – now we were chasing ghosts.

Until, after months of searching, we finally found our glimmer of hope. On November 8, 2012 we found a healthy adult male Atelopus perched on a mossy boulder, unconcerned that a cross-continent scramble had been underway for months, just to find him. We sat in the rain, watching him and snapping pictures. We collected non-invasive samples for diagnostic and genetic testing and then, somewhat reluctantly, we said good-bye and wished him well. We were overjoyed…. and here’s why: One small frog in the wild suggests that there are at least some surviving populations out there. And if there is even one small population holding on, there is hope – not just for that population, or even for the species, but for the whole genus. Having evidence to support that hope, in the form of that single, small and beautiful frog, is something even better than holding a winning lottery ticket with his picture on it.

To find out more about Project Atelopus follow their field blog here.

Mission Critical: Amphibian Rescue

This award-winning documentary featuring our race to find a cure for a deadly amphibian disease and to build an amphibian ark in Panama is now available for FREE.  Watch the trailer below and download the full feature if you would like to see more on the itunes store for a limited time only.

CLICK HERE to download the full episode of Smithsonian Networks Mission Critical: Amphibian Rescue film. FREE FOR A LIMITED TIME ONLY!

Frog Poetry and the Washington Post

Washington Post

On Dec. 30, the Washington Post ran a front-page story about the rescue project.

The year ended on a high note for the Panama Amphibian Rescue and Conservation Project. William Booth, a science writer for the Washington Post, joined rescue project researchers on a field expedition and his story about the rescue project came out on the front page of the Post on Dec. 30. The story inspired one reader, Tim Torkildson, to share a lovely poem about frogs and the disease that is wiping them out.

Booth also did this NPR interview about his recent trip to Panama.

If you saw the story and are interested in making a donation to the rescue project, please follow this link to the National Zoo’s website.

THE FROG
by Tim Torkildson

The frog is an amphibian
Who thrives most ev’rywhere,
From the dry Namibian
To just off ol’ Times Square.
The ones who have a bumpy skin,
With warts and pits and nodes,
Are the closest Phylum kin;
We simply call them toads.
The bullfrogs in the early spring
give ponds reverberation
With their raucous verbal fling,
Attempting procreation.
The have a courtship ritual
that’s called, I think, amplexus,
Which gives them fits conniptual
Between the two odd sexes.
A little boy will manage to
Corral a tadpole, yes,
And give it quite a slimy view
Right down his sister’s dress!
And did you know the urine from
a pregnant lady will
cause some frogs to lay a scum
of eggs, with no male thrill?
And so they’re useful critters,
As the French will tell you so;
Their legs taste good in fritters,
Are mistaken for turbot.
And what of cane toads, mind you,
Where, if you lick the skin,
The psychedelics blind you
To sorrow, grief and sin?
But frogs, those little gargoyles,
Which are funny in cartoons,
Are engaged in lethal broils
That leaves their lives in ruins.
A fungus known as “Bd” kills
The frogs down in Belize,
Then jumps the valleys and the hills
So others it may seize.
The Costa Rica Golden Toad
Is now extinct, alack.
More are headed down that road,
Since habitat is slack.
Toxins give some frogs three legs,
Which doesn’t help them jump.
Instead they are like clumsy kegs
Who in the water flump.
Scientists preserve some frogs
In habitats in labs.
Dressed in their starched, stiff white togs
They keep meticulous tabs.
To save the frogs, oh please donate
A dollar or a yuan,
So the polliwog birth rate
Will someday be a shoo-in!

Using genetic tools to understand and manage chytridiomycosis

Lowland leopard frog (Lithobates yavapaiensis)

The lowland leopard frog is the focus of SCBI postdoc Anna Savage's work looking at the relationship between genes and chytrid resistance.

Chytridiomycosis, the disease wiping out frog species around the world, was described in 1999 by a team of researchers at the Smithsonian and the University of Maine. Today, in addition to creating an insurance population for various Panamanian species, the Smithsonian Conservation Biology Institute aims to find a way to manage this disease. One of the most promising solutions to stopping the killer may rest in genetics. SCBI scientists are looking to identify genes within frogs that provide resistance to the pathogen or that make them more susceptible to it.

Researchers pursuing this approach are optimistic that genetics could provide different answers than those offered by probiotics, which SCBI is also pursuing. The genetic approach is one based on natural selection.

“If you look across species, including humans, diseases rarely wipe out an entire species without any evidence of resistance, regardless of how virulent they are,” said Anna Savage, an postdoctoral fellow in SCBI’s Center for Conservation and Evolutionary Genetics studying the genetics of chytrid. “Immune systems are so complex that there’s a strong possibility for the development of resistance. The probability that a species develops no resistance to a disease is rather small.”

Genetics research within the last decade has identified frogs with varying degrees of resistance to chytrid. Savage is focusing her research on the lowland leopard frog (Lithobates yavapaiensis), which exhibits an intermediate level of resistance to the pathogen. Some individuals demonstrate resistance while others of the same species die if infected with chytrid. The identification of genetic variations between the individuals holds the potential of being the answer between life and death. One of the new frontiers for genetic research is the examination of a frog species’ immune system genes.

“If we can identify the genes responsible for resistance, we can breed the animals in captivity to ‘spread’ this genetic resistance and give adaptation a headstart,” Savage said. “This area of research holds the potential for creating populations of self-sustaining frogs that confer resistance to the rest of the population through reproduction.”

Anna Savage with bullfrog

Savage's research could hold the key to putting a stop to a deadly pathogen killing frogs around the world.

In order to understand a frog’s response to chytrid, the focus must be broadened to understanding how immune system genes interact with one another and which ones are being expressed during resistance. Savage is using this approach to understand chytrid susceptibility in lowland leopard frogs that are being raised at the Smithsonian’s National Zoo. This approach could potentially help scientists identify genes responsible for chytrid resistance. While this type of research shows considerable potential, researchers are only just beginning to scratch the surface.

“Disease outcomes from chytridiomycosis can depend on several factors,” said Brian Gratwicke, SCBI wildlife biologist and Panama Amphibian Rescue and Conservation Project international coordinator.  “Some frogs appear to have innate resistance to the disease and produce antimicrobial peptides from glands in their skin. It is possible that some might acquire resistance through exposure, while other frogs have beneficial anti-fungal skin bacteria or a behavioral preference for temperatures that are bad for the fungus. As the fight against chytrid continues, we remain hopeful that the answers are out there and that Dr. Savage’s work will give us some insight into how this system really functions.”        

–Will Lazaro, Smithsonian’s National Zoo

(Frog photo by Jared Grummer; photo of Anna Savage by Dennis Caldwell)

The Wyoming Toad: Almost extinct in America’s backyard

Wyoming toad

In 1993 what was thought to be the last 10 living toads were captured at Mortenson Lake and brought into captivity to start a breeding program. (Photo courtesy of Cheyenne Mountain Zoo)

The Wyoming toad (Bufo hemiophrys) was discovered in 1946 by Dr. George T. Baxter,  a University of Wyoming professor. This toad was originally considered a subspecies of the Canadian toad (Bufo hemiophrys). The historic range of the toad included flood plains of the Big and Little Laramie Rivers and the margins of ponds in the Laramie Basin within 30 miles of the city of Laramie, Wyo.

Wyoming toad tadpoles

More than 100,000 tadpoles and toadlets have been reintroduced since 1995. (Photo courtesy of Cheyenne Mountain Zoo)

Wyoming Toads In Decline

  • Once was one of the most plentiful vertebrate species in the Laramie River Basin Wyoming.
  • Rapid declines in the toad population seen in the 1970’s, the exact cause of these declines is unknown. Possible causes include aerial spraying of pesticides, chytrid fungus, red-leg disease and habitat alteration.
  • Federally listed as an endangered species in January of 1984.
Wyoming toads eggstrand

The Wyoming toad was declared “extinct in the wild” and still is. (Photo courtesy of Cheyenne Mountain Zoo)

US Fish and Wildlife Service Recovery Plan

  • The first Wyoming Toad Recovery Group was formed in September 1987.
  • In 1993 what was thought to be the last 10 living toads were captured at Mortenson Lake and brought into captivity to start a breeding program.
  • The Wyoming toad was declared “extinct in the wild” and still is.
  • The first successful captive reproduction of the toad occurred in 1994 at the Sybille Wildlife Research and Conservation Center in Wyoming.
  • Local land owners provide safe harbor sites for the reintroduction of Wyoming toads.
  • More than 100,000 tadpoles and toadlets have been reintroduced since 1995.
  • Sites are surveyed annually to monitor population numbers. So far we have seen mixed results.

American Zoo and Aquarium Association (AZA) Species Survival Plan (SSP)

  • The SSP was formed in 1996.
  • Only seven AZA accredited zoos and two Fish and Wildlife facilities participate in the SSP program by breeding toads.
  • Volunteers from zoos travel to Laramie to assist in surveys for toads each summer.

For more information, visit www.wyomingtoad.org

Della Garelle, Cheyenne Mountain Zoo

Happy Third Annual Golden Frog Day!

Panamanian golden frogs

In 2010, the National Assembly of Panama passed a law that honors the significance of one of the most striking amphibian species, the Panamanian golden frog. That day is Aug. 14. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

It’s National Golden Frog Day in Panama today and we’re celebrating here on the blog with some thoughts from the rescue project’s partners and other stakeholders about what the golden frog means to each of us individually, to Panama’s culture, to the ecosystem and to the world:

Adrian Benedetti, Smithsonian Tropical Research Institute
“The golden frog was the first animal to capture my imagination when I returned to Panama after living abroad for 12 years. The fact that this little animal had such a grip on local myth and legend makes it almost magical.”

“La Rana Dorada fue el primer animal en capturar mi imaginación al regresar a Panamá después de 12 años de estar fuera del país. El hecho de que este animalito ha tenido un impacto tan grande en la mitología y leyenda local lo hace casi mágico.”

Brian Gratwicke, Smithsonian Conservation Biology Institute
“I actively search for a little glimmer of neon-yellow peeking out from behind a rock every time I hike up a river in El Valle de Anton, but I’m always disappointed. I guess I’m chasing that same ecstatic rush that people get when they twitch a new bird species, or see a grizzly bear catching a salmon in Alaska. I think anyone who has seen charismatic wildlife in wild, natural landscapes where they belong can understand why it would be so thrilling to play a small role in bringing golden frogs back from the brink.”

Golden frogs

In the market at El Valle de Antòn, you will see golden frogs by the thousands either as enamel-painted terracotta or on hand-carved tagua nuts. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

Edgardo Griffith, EVACC
“The only reason golden frogs and other species are going extinct is because of us. We are the ones that created the problems they and their habitats are facing, so we are the ones that have to find the solutions. It is our responsibility big-time, especially because the more responsible we are with the environment, plants and animals, the more chances of survival the future generations of our own kind will have. In my opinion, saving wildlife today is the only way we have to assure the survival of our very own species.”

“I recognize that not all amphibians are physically beautiful, but I love them all and consider all of them master pieces of DNA. However, the Panamanian golden frog is indeed colorful, elegant and very wise. Knowing a little bit about their natural behavior makes me appreciate them even more. I think they are one of those things where Mother Nature just went overboard.”

Heidi Ross and Edgardo Griffith, EVACC
“The golden frog is the most significant, important and charismatic amphibian in Panama. It is part of our culture and a very important member of the amphibian community. From an ecological point of view, it is one of those species that is extremely susceptible to even minimal environmental changes. It is also a species that has been used as a flagship to conserve other amphibian species.”

Panamanian golden frog

Panamanian golden frogs are extinct in the wild, but a number of zoos have successful breeding programs that aim to keep the species alive. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

“To witness an entire population disappear is just devastating, and heartbreaking. Now every time we go back to the sites where we used to work with golden frogs, all we do is remember where we used to find them and imagine what it would be like to hear their characteristic whistle-like call again. But after a few hours of not finding them, or hearing them at all, a horrible feeling of void and silence fills us up. This is the time to get out of there. In other words, it is sad, very sad to know that they are all gone now, just like living the worst day of your life over and over again. That is how it feels to go to the field now. They are some of the many ghosts of the stream now.”

Mason Ryan, University of New Mexico
“This frog is such an important symbol to Panama and now the entire conservation community that saving them is our responsibility. They are colorful, have neat behaviors, and are overall captivating. Future generations should have the joy and wonderment of seeing these frogs.”

“I spent five years looking for a closely related species in Costa Rica, the Harlequin frog, and never found one. I never dreamed I would have the opportunity to see any frogs of the genus Atelopus. But then I started my first field season at El Cope with Karen Lips. Early in the season we were walking one of the main streams in the park and there it was. An adult golden frog hopping along the bank of the stream. It was a magical experience to see this golden frog with block spots in real life! I am pretty sure I was smiling the next two days. It was a dream come true to see one of these animals in its natural habitat. Over the years I saw dozens more and never tired of seeing them. I’ll never forget that first one.”

Matt Evans, Smithsonian’s National Zoo

Celebrating tadpole diversity

Tadpoles

The ability of certain Panamanian species to survive will depend on the ability of the rescue project to perfect specialized care for the individual species. (Photo by Lindsay Renick Mayer, Smithsonian

When we talk about frog diversity, we always mention how many species there are, or how they are found all over the world. We say how much frogs vary in size, or how colorful they can be. This is all true: there are more than 4,900 frog species, found on every continent, ranging from ½-inch long to more than a foot, that come in every color of the rainbow. It makes sense, then, that frogs are just as diverse during their other stages of the life cycle. Tadpoles, in fact, are among the most diverse vertebrates on Earth and are themselves morphologically and behaviorally unique from their adult counterparts.

Special Adaptations

Depending on the species, tadpoles can stay in the larval stage from eight days to two years, and vary in length from 1 to 4 inches. Overall, there is greater tadpole diversity in the tropics, but variations occur within habitats, as well. Even tadpoles with the same feeding habits can have diverse mouth shapes or behaviors. For example, tadpoles of the Asian horned frog (Megophrys montana) have an upturned mouth because they eat from the surface. Recently, however, scientists have observed a Honduran tadpole called Duellmanohyla soralia that also eats from the surface, but has a mouth in the more traditional spot. Instead, the Duellmanohyla soralia turns its body upside-down to reach the surface.

“We see tadpoles solving the same problems of survival in different ways,” says Dr. Roy McDiarmid, an amphibian zoologist and tadpole expert at the National Museum of Natural History. “This is where their diversity derives from.”

These variations show how tadpoles’ features are shaped largely by their surrounding environments. For example, tadpoles seem especially good at responding to strong predator presence. Over time tadpoles can grow their tails longer and deeper if there are numerous predators, allowing them to swim faster and look bigger. For European common frog (Rana temporaria) tadpoles, longer tails increase their chances of escape from predators up to 30 percent, according to the Institute of Zoology.

Like tail length, other adaptations can protect tadpoles from being eaten. While the majority of tadpole species have brown or faded coloration, several are multicolored. Contrary to its name, Cope’s gray tree frog (Hyla chrysoscelis) tadpoles grow red tails in response to the presence of dragonflies. Called aposematism, vibrant colors make these tadpoles appear larger or distasteful to their predators.

Researchers have only recently discovered other survival mechanisms that tadpoles have developed. In 2006, scientists discovered that if attacked, red-eyed tree frog (Agalychnis callidryas) embryos can hatch themselves within seconds and escape into the water below. These embryos can interpret vibrations on the water with astonishing precision.

“It turns out that when a snake bites into a gooey mass, all the embryos try to wiggle free,” Karen Warkentin, a biologist working at the Smithsonian Tropical Research Institute in Panama, told National Geographic.  “A wasp’s more focused attack prompts only neighboring eggs to hatch. And a rainstorm triggers nothing at all.”

Other recent research has looked at tadpole sensory input, such as smell and sound. In 2009, researchers at the University of California Davis determined that wood frog (Rana sylvatica) tadpoles can “smell” their primary predator, the salamander. The “odor” of a salamander in the water caused tadpoles to freeze. The strength of the scent determined how long the tadpoles remained still. In 2010, Dr. Guillermo Natale discovered the first evidence of aural larva communication. Natale heard tadpoles of the Bell’s horned frog (Ceratophrys ornate) “screaming” underwater when a threat was present.

Discovery

Tadpole

The amount of tadpole diversity rivals that of their adult life forms. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

New and unpredictable tadpole discoveries continue to go on worldwide. For example, biologists at the Australian Museum in Sydney recently discovered that tadpoles of the vampire flying frog (Rhacophorus vampyrus) have small black fangs, instead of traditional mouthparts. In general, scientists estimate that more than 1,000 frog species have yet to be discovered, not to mention all the intricacies of their life stages.

Tadpoles are also essential for understanding the dramatic decline in frog populations. Chytrid, the epidemic that has affected 30 percent of the world’s amphibian population, is the lead cause of this decline. In tadpoles, chytrid only infects the keratin around their mouths. However, as they metamorphose into frogs, chytrid fatally spreads throughout their bodies. By studying tadpoles, we can better understand how frogs contract and carry chytrid.

“When frog species are disappearing like they are, you would want to know what’s going on at each stage of the life cycle, egg to larva to juvenile to adult–everything,” McDiarmid says.

The Challenges of Breeding

For the Panama Amphibian Rescue and Conservation Project, every tadpole means the chance for a species to survive. But because many of the rescue project’s priority species have never been kept or bred in captivity before, rearing tadpoles can mean a steep learning curve.

“Breeding frogs isn’t just about putting a male and female together and hoping for eggs,” said Lindsay Renick Mayer, spokesperson for the rescue project. “It’s about specialized husbandry for each individual species among a diverse array and unfortunately for some of these species we’re learning those skills even as the species dwindles down to just a few remaining individuals. Whether these species are one day returned to the wild depends on the rescue project’s success in perfecting the variety of care in a short period of time.”

Nadia Hlebowitsh, Smithsonian’s National Zoo

New experiment may offer hope for frogs facing chytrid

Probiotics bath

The golden frogs were given a bath in one of four probiotic solutions. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

We usually think of bacteria as bad for us, but that isn’t always the case. For us humans, the most common examples of helpful bacteria, or probiotics, live in yogurt. Now, scientists believe amphibian probiotics may be the key to fighting chytridiomycosis, the fungal disease devastating frogs around the world.

A few years ago, Reid Harris, a biology professor at James Madison University, discovered that local salamanders that could survive chytrid played host to bacteria in their skin. Now, Brian Gratwicke, a research biologist at the Smithsonian Conservation Biology Institute, is collaborating with a team from Virginia Tech, James Madison, Villanova and Vanderbilt Universities in an experiment to see if similar bacteria can protect the Panamanian golden frog, which he calls “the poster-child for amphibian conservation.”

The first step is to find a probiotic that will stick to the golden frogs. In early December, the team began giving golden frogs baths using four different types of bacteria. Researchers gathered the potential probiotics from frogs in Panama in 2009. The finalists were chosen based on their ability to prevent chytrid growth in lab tests, with a preference for bacteria that are common in close relatives of Panamanian golden frogs.

Every two weeks, each frog is swabbed to check whether its probiotic has made itself at home. The tests take some time, so a month and a half in, the team is still waiting for results to see which probiotics are sticking. But they do have some good news already.

“The bacteria haven’t been causing any problems with the frogs and they all look healthy,” said Gratwicke, who emphasizes how important it is to use only beneficial bacteria. In addition to tracking weight gain and other visible characteristics, Shawna Cikanek, a student at Kansas State College of Veterinary Medicine is using frog poop to study stress hormones to get a better picture of the animals’ overall health and whether the bacteria are causing any stress.

The probiotics that stick to the frogs for a full three months will move on to the next round of tests, when bacteria-shielded frogs will be infected with chytrid to check for any adverse effects.

“Hopefully, the bacteria are going to do their thing and protect these little guys,” said Matt Becker, a PhD candidate from Virginia Tech who is conducting the experiment. Whatever probiotics make the cut will be tested again on golden frogs bred in Panama before scientists develop a final plan.

So far, chytrid has defied attempts to stop it. Scientists may be able to selectively breed frogs resistant to chytrid, but there has been very little work done so far in that direction. But there are high hopes for probiotics’ potential to protect frogs. “It’s a long shot, but it’s our best shot,” said Gratwicke.

Becker hopes that one day, probiotics will allow Panamanian golden frogs to return to their homes. “These guys are really neat and it’s so sad not to see them in the wild,” he said. “We have a moral obligation since indicators are pointing to humans as major spreaders of the disease through the frog trade.”

Meghan Bartels, Smithsonian’s National Zoo