On May 30, 2019 a special issue of the Journal Biological Conservation entitled ‘Amphibian conservation in the Anthropocene: Progress and challenges‘ Edited by Vincent Devictor, Evan Grant, Erin Muths, Benedikt Schmidt, Silviu Petrovan was published. The focus of this issue is on examples of potential solutions to the amphibian crisis that are directly relevant to, and integrated with conservation management actions.
The issue features a case study on Atelopus in Panama, updating the known historical distribution records and modeling potentially suitable habitat (below).
The paper also updates the IUCN conservation status for each Panamanian Atelopus species and the status of each of these species in captive populations, with commentary on the potential use of the captive population in research to find solutions that may be useful in restoring wild populations.
An international study led by The Australian National University (ANU) has found that a fungal disease has caused dramatic population declines in at least 501 amphibian species, including 90 extinctions, over the past 50 years. The study involved collaborations with 41 different amphibian and wildlife disease experts from around the world. Smithsonian scientists contributed data from Panama—one of the worst-hit areas of the world by the disease—for the study.
Of the 90 confirmed extinctions of frogs across the globe, eight of those species were from Panama. Another 52 species of frogs in Panama have experienced more than a 90 percent decline.
“This study confirms that we are not dealing with a unique problem in Panama,” said Brian Gratwicke, amphibian biologist, international coordinator of the Panama Amphibian Rescue and Conservation Project, and one of the co-authors of the study who provided data. “If we or anyone does find a solution or cure for chytrid, it will likely have global implications.”
Collaborators like Smithsonian scientists allowed the lead researchers from ANU to get a first-hand insight into the conditions on-the-ground in countries around the world.
Chytridiomycosis, which eats away at the skin of amphibians, has completely wiped out some species, while causing more sporadic deaths among other species. Amphibians, which commonly live part of their life in water and the other part on land, mainly consist of frogs, toads and salamanders.
The deadly disease is present in more than 60 countries – the worst affected parts of the world are Australia, Central America and South America. The researchers found that chytridiomycosis is responsible for the greatest loss of biodiversity due to a disease.
The disease is caused by chytrid fungus, which likely originated in Asia where local amphibians appear to have resistance to the disease.
The unprecedented number of declines places chytrid fungus among the most damaging of invasive species worldwide, threatening similar numbers of species as rats and cats.
Lead researcher Ben Scheele, Fenner School of Environment and Society at ANU, said highly virulent wildlife diseases, including chytridiomycosis, were contributing to the Earth’s sixth mass extinction.
“The disease we studied has caused mass amphibian extinctions worldwide. We’ve lost some really amazing species,” said Scheele.
He said more than 40 frog species in Australia had declined due to this disease during the past 30 years, including seven species that had become extinct.
“Globalisation and wildlife trade are the main causes of this global pandemic and are enabling disease spread to continue,” said Scheele. “Humans are moving plants and animals around the world at an increasingly rapid rate, introducing pathogens into new areas.”
Scheele said improved biosecurity and wildlife trade regulation were urgently needed to prevent any more extinctions around the world.
“We’ve got to do everything possible to stop future pandemics, by having better control over wildlife trade around the world.”
Scheele said the team’s work identified that many impacted species were still at high risk of extinction over the next 10–20 years from chytridiomycosis due to ongoing declines.
“Knowing what species are at risk can help target future research to develop conservation actions to prevent extinctions.”
Scheele said conservation programs in Australia had prevented the extinction of frog species and developed new reintroduction techniques to save some amphibian species.
“It’s really hard to remove chytrid fungus from an ecosystem – if it is in an ecosystem, it’s pretty much there to stay unfortunately. This is partly because some species aren’t killed by the disease,” he said.
“On the one hand, it’s lucky that some species are resistant to chytrid fungus; but on the other hand, it means that these species carry the fungus and act as a reservoir for it so there’s a constant source of the fungus in the environment.
Video by Katie Garrett and Jonathan Kolby
Citation to the Paper: Scheele, B.C., Pasmans, F., Skerratt, L.F., Berger, L., Martel, A., Beukema, W., Acevedo, A.A., Burrowes, P.A., Carvalho, T., Catenazzi, A., De la Riva, I., Fisher, M.C., Flechas, S. V, Foster, C.N., Frías-Álvarez, P., Garner, T.W.J., Gratwicke, B., Guayasamin, J.M., Hirschfeld, M., Kolby, J.E., Kosch, T.A., La Marca, E., Lindenmayer, D.B., Lips, K.R., Longo, A. V, Maneyro, R., McDonald, C.A., Mendelson, J., Palacios-Rodriguez, P., Parra-Olea, G., Richards-Zawacki, C.L., Rödel, M.-O., Rovito, S.M., Soto-Azat, C., Toledo, L.F., Voyles, J., Weldon, C., Whitfield, S.M., Wilkinson, M., Zamudio, K.R., Canessa, S., 2019. Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity. Science (80-. ). 363, 1459 LP-1463. https://doi.org/10.1126/science.aav0379
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.
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: (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 (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.
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.
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 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
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Scientists 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.
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
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.
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.
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.
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.
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.
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,
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!
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.”
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)
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.
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.
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.