In unprecedented effort, more than 40 organizations from 13 countries come together to protect and restore harlequin toads, the jewels of South and Central America, hard hit by a deadly amphibian disease

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With the formation of the Atelopus Survival Initiative (ASI)–a new alliance of more than 40 organizations from 13 countries–comes a new day for harlequin toads, the jewels of South and Central America’s forests and creeks and a group of amphibians hardest hit by the deadly chytrid fungus Batrachochytrium dendrobatidis (Bd). 

While amphibian researchers and conservationists have worked for many years to save harlequin toads (which make up the Atelopus genus) and groups of species in individual countries, the ASI is bringing them together for the first time to pool the resources, decades of experience and knowledge necessary to prevent the extinction of the entire genus of harlequin toads across the region where these species still survive. 

“As an incredibly diverse group of amphibians facing a number of threats, harlequin toads require innovative solutions coming from a diverse group of individuals and organizations with different expertise, knowledge and capacities,” said Lina Valencia, ASI founder, co-coordinator of the IUCN SSC Amphibian Specialist Group Atelopus Task Force and Andean countries coordinator for Re:wild, one of the primary ASI conveners. “More than ever before, we need a constellation of champions working together to bring harlequin toads back from the brink of extinction. The ASI underscores the vital need to implement on-the-ground conservation actions that will mitigate the main threats to this beautiful group of amphibians.”

Over the past few decades, many harlequin toad species have suffered severe population declines and extinctions throughout their range. Today, of the 94 harlequin toad species that have been assessed by the IUCN, 83 percent are threatened with extinction, while about 40% of Atelopus species have disappeared from their known homes and have not been seen since the early 2000s, despite great efforts to find them. Four harlequin toad species are already classified as extinct, according to the IUCN Red List of Threatened Species, but this number is likely higher. 

The fungus Batrachochytrium dendrobatidis (Bd) causes the lethal disease chytridiomycosis, which has resulted in amphibian declines all around the world, including in South and Central America, Australia and the western United States. Although Bd may likely be the primary driver of these declines, a number of other threats are exacerbating the precipitous drops in population numbers. This includes habit destruction and degradation (as the result of animal agriculture, logging, mining and infrastructure development), the introduction of invasive species such as the rainbow trout that prey on harlequin toad tadpoles, pollution, illegal collection for the pet trade, and the effects of climate change.

The ASI and its members, including governments, local communities and Indigenous peoples, will collaboratively address each of these threats–and new ones as they arise–across the genus’s full range, taking into account the social, political and cultural realities of each of the 11 countries where harlequin toads are found. 

“With their beautiful songs and unique lifestyles, amphibians are among the most extraordinary animals on Earth, and among them, harlequin toads stand out for their amazing colors,” said Luis Fernando Marin da Fonte, coordinator of the ASI and director of partnerships and communications for the Amphibian Survival Alliance. “But these colorful and delicate jewels are becoming increasingly rarer. Harlequin toads must be protected not only because of their beauty and uniqueness, but also because of their intrinsic value and biological, ecological and even cultural importance.”

The initiative’s newly developed Harlequin Toad (Atelopus) Conservation Action Plan (HarleCAP) provides the roadmap for conserving and restoring harlequin toads as a genus and their habitat. The action plan’s goals, which ASI aims to achieve by 2041 (the 200th anniversary of the description of the genus Atelopus), include:

  • developing and implementing innovative methods to mitigate chytrid’s impacts on harlequin toad populations and better understanding why some species are less susceptible to the effects of chytrid;
  • protecting and restoring harlequin toads’ forests and watersheds;
  • creating and maintaining conservation breeding programs;
  • searching for species that are lost to science and filling in other gaps in scientific knowledge about harlequin toads;
  • sharing stories that will transform harlequin toads into symbols of hope for the region and the world and a flagship for conservation success, and demonstrate a commitment to the conservation of harlequin toads; 
  • ensuring the Atelopus conservation network has the technical, logistical, and financial support to secure the long-term conservation of harlequin toads

“The establishment of collaborative initiatives at the international and regional level is essential to coordinate efforts and obtain tangible results that have an efficient and real impact on the conservation of an endangered species,” said Gina Della Togna of the Universidad Interamericana de Panamá, Panamá. “The Atelopus Survival Initiative is a concrete example, which not only aims to conserve one species, but an entire genus, perhaps the most threatened by the global amphibian extinction crisis.”

Harlequin toads are found from Costa Rica in the north to Bolivia in the south, and Ecuador in the west and French Guiana to the east. They are known as the jewels of South and Central America in part because of their beautiful and varied colors, which range from orange, green, yellow, brown, black, red, and sometimes even purple. They are celebrated in a number of Latin American cultures, including Indigenous cultures, and across entire countries, like in Panama, where the national animal is the Panamanian golden toad.

Like other amphibians, harlequin toads support healthy ecosystems. Their tadpoles depend on clean water and, because of this, the presence of harlequin toads indicates better quality water in an ecosystem, while their decline or absence is often the first sign of an ecosystem in trouble. 

“Protecting and restoring harlequin toads and their habitats will also benefit the species that share the ecosystems in which they live and that provide water to tens of millions of people, and ultimately all life on Earth,” Valencia said. “And we’re hoping that the ASI will be a successful model that conservationists can emulate for other groups of threatened species.”

 The Atelopus Survival Initiative includes national and international conservation groups, zoos, captive breeding centers, academic institutions, governments and local communities. Its current members represent the following organizations: Amphibian Ark, Amphibian Survival Alliance, Asociación Pro Fauna Silvestre  – Ayacucho, Bioparque Municipal Vesty Pakos, Bolivian Amphibian Initiative, Centre National de la Recherche Scientifique, Centro de Conservación de Anfibios AMARU, Centro Jambatu de Investigación y Conservación de Anfibios/Fundación Jambatu, CORBIDI, DoTS, El Valle Amphibian Conservation Center Foundation, Facultad Latinoamericana de Ciencias Sociales, Florida International University, Fort Worth Zoo, Fundación Atelopus, Fundación Zoológica de Cali, Universidad del Tolima (GHEE), Grupo de Trabajo Atelopus Venezuela, Image Conservation, Instituto Nacional de Pesquisas da Amazônia, Instituto Venezolano de, Investigaciones Científicas, Ministerio del Ambiente de Perú, MUBI (Museo de Biodiversidad del Perú), Parque Explora, Parque Nacional Natural Puracé, Photo Wildlife Tours, Pontificia Universidad Católica del Ecuador, Pontificia Universidad Javeriana, Re:wild, San Diego State University, Smithsonian Tropical Research Institute, Trier University, Universidad de Antioquia, Universidad de Costa Rica, Universidad de los Andes, Universidad del Tolima, Universidad del Magdalena, Universidade Federal do Pará, Universidad Nacional, Universidad Interamericana de Panamá, Universidad Nacional de Colombia, Universidad San Francisco de Quito, Universidade Estadual de Campinas, Universidade Federal do Oeste do Pará, University of Nevada, Reno, University of Notre Dame, University of Pittsburgh, WCS (Wildlife Conservation Society), WCS Colombia, Zoológico Cuenca Bioparque Amaru

New publication! IUCN Guidelines for amphibian reintroductions and other conservation translocations

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An exciting new publication has just been released by the International Union for the Conservation of Nature (IUCN) of best practice guidelines for a wide range of amphibian conservation translocations. The project was many years in development through the coordinated effort of numerous translocation specialists across the globe, but the project the led by the Panama Amphibian Rescue and Conservation Project’s post-doctoral research fellow Dr. Luke Linhoff. The guidelines cover the reasons for conducting amphibian translocations, pre-translocation planning and risk assessment, and also cover important topics such as disease, welfare, human social dimensions, post-release monitoring and reporting results.

A free digital download and more information on the guidelines can be found at: https://www.iucn-amphibians.org/iucn-guidelines-for-amphibian-reintroductions-and-other-conservation-translocations/

Meet the spectacular Borderlander frog Atelopus fronterizo, Panama’s newest frog species!

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Milan Vesely and Abel Batista scientifically described Panama’s seventh harlequin frog species in the journal Zoological Research in April 2021. This beautiful harlequin frog species has been in biological collections for some time, the first museum specimen was first collected by Henri Pittier at Puerto Obaldlia in 1911, but has previously been assumed to be related to other sister species that it closely resembles. Historically collected formalin-preserved specimens were unsuitable for genetic analyses and so the frog remained undescribed.

Vesely and Batista conducted expeditions to the Darien to collect new specimens and this allowed them to conduct genetic analysis showing that this species is most closely related to Atelopus certus and Atelopus glyphus, but is genetically distinct enough to warrant recognition as a species. It also has a slightly different call and morphological characteristics that are also described in the paper.

Borderlander Harlequin Frog

Atelopus fronterizo Photo by Abel Batista, UNACHI-Fundación Los Naturalistas-SNI (SENACYT)

They named the frog Atelopus fronterizo to refer to borderland inhabitants and the Panamanian border security force who protect the Darien mountain range in NE Panama on the border where this frog is found. Like other harlequin frog species in Panama, even though they live in well-protected habitat, they are Likely Critically Endangered due to the threat of the amphibian chytrid fungus that has caused the declines of other Atelopus species in Panama.

Vesely, M. and Batista, A., 2021. A new species of Atelopus (Amphibia: Bufonidae) from eastern Panama. Zoological research, pp.272-279.

Spindly leg syndrome is reduced by increasing calcium hardness of water used to rear tadpoles

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Atelopus varius metamorph with spindly leg (left) and without spindly leg (right)

Rearing frogs in captivity has its own unique challenges, one problem that has been a persistent issue in the Panama Amphibian Rescue and Conservation Project is spindly leg syndrome (SLS). This common musculoskeletal disease is mostly associated with captive amphibian breeding. SLS is a condition where legs of newly metamorphed amphibians, with otherwise healthy and typical development, are poorly developed and cannot support the weight or newly metamorphed froglets. Ultimately, SLS leads to death as the animal is unable to move or feed themselves. A brief review online will reveal a host of theories and potential remedies for the condition ranging from parental nutrition to water quality and dietary supplements, but there are very few replicated peer-reviewed experiments identifying the cause of this disease.

Elliott Lassiter and Orlando Garcés with the experimental rearing setup

As an intern with the Panama Amphibian Rescue and Conservation Project I teamed up with Orlando Garcés a graduate of the University of Panama and employee of the project to conduct an experiment primarily funded by the Morris Animal Foundation. We had observed that SLS was most prevalent in water that did not have any supplementary calcium and we knew that incoming water to our facility was very soft (lacking in calcium hardness). Bone growth is the symptom of SLS, therefore, we decided to look at the principle minerals affecting bone growth: calcium and phosphate. Tadpoles can gain calcium through their diet but they absorb about 70% of their calcium from the water through their gills and skin. The collected calcium is then stored in endolymphatic sacs in their heads and used during metamorphosis when tadpoles’ skeleton turns from cartilage into bone and limbs begin to grow.

We took 600 Atelopus varius tadpoles and divided them into three calcium treatments (low, medium, high) and then divided those into two groups one with added phosphate and one without added phosphate.  We monitored our tadpoles until they metamorphosed, at which point we looked at their legs and body posture to determine whether or not they had SLS. We found that calcium supplementation drastically increased survivorship overall and that the medium and high calcium groups had less SLS than the low calcium groups. Addition of phosphate also decreased the prevalence of SLS in low calcium treatment.

Based on the results of this study we were able to determine that SLS in harlequin frogs, is linked to an imbalance in calcium and phosphate homeostasis. Therefore, our current husbandry recommendation to reduce SLS in frogs and toads is to consider checking water hardness to determine if it is too soft. We also advise against over feeding tadpoles which has been shown to cause an increase in SLS prevalence in another experiment. We hope that our findings can guide future SLS research and help to lower the prevalence of SLS in captive amphibians, improving animal welfare. This research will help to improve the long-term sustainability of captive populations while researching solutions for the amphibian chytrid fungus and eventual reintroduction of these frogs back into the wild.

Lassiter, E., Garcés, O., Higgins, K., Baitchman, E., Evans, M., Guerrel, J., Klaphake, E., Snellgrove, D., Ibáñez, R. and Gratwicke, B., 2020. Spindly leg syndrome in Atelopus varius is linked to environmental calcium and phosphate availability. PloS one, 15(6), p.e0235285.

By Elliot Lassiter and Orlando Garcés

A vigorous immune response to the chytrid fungus is associated with susceptibility to the disease

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For frogs dying of the invasive chytridiomycosis disease, the leading cause of amphibian deaths worldwide, the genes responsible for protecting them may actually be leading to their demise, according to a new study published today in the journal Molecular Ecology by Smithsonian Conservation Biology Institute (SCBI) and University of Central Florida researchers.

The lowland leopard frog, found in river drainages in Arizona, is one of a few amphibian species in which some individuals survive infection by Batrachochytrium dendrobatidis chytrid fungus (Bd) while other individuals do not—even when they live in the same local population.

In a study of lowland leopard frogs infected with Bd, the fungus that causes the disease chytridiomycosis or chytrid, researchers found that frogs that died from the disease had higher expression of major histocompatibility complex and other immune system genes than frogs that survived it. Those genes help organisms fight off infections and foreign substances.

“This result was totally counterintuitive and the opposite of the pattern we expected to recover,” said Anna Savage, the study’s lead author, an associate professor in UCF’s Department of Biology and former postdoctoral fellow at SCBI’s Center for Conservation Genomics (CCG).

Comparison of differential gene expression in control, early infected, surviving and susceptible frogs in both the spleen (left) and skin (right). 

“My previous research on these immune genes showed that some variants were associated with higher survival to Batrachochytrium dendrobatidis, so I hypothesized that those genes were enabling the frogs to have a stronger immune response that would kill the fungus,” she said. “Instead, it seems like those stronger responses are linked to susceptibility, and the genes associating with survival are linked to reduced immune function.”

Savage said acquired immune responses can be very potent, require a lot of energy from the body and can sometimes produce toxic byproducts that harm the host and the pathogen.

“Immune responses are much more complex than just an on-off switch,” she said. “A big part of the immune system is regulating the type, timing and dosage of a particular response, and if any of those components get dysregulated, it can have extremely negative consequences.”

She said, for instance, Batrachochytrium dendrobatidis suppresses the host immune system by killing B and T lymphocytes. “Because those are the same cells that proliferate during acquired immune responses, producing lots of those cells might just be wasting energy on something that chytrid can easily destroy,” she said.

Amphibian populations are in decline around the world, with two-thirds of the world’s 8,000 species considered to be threatened and nearly 200 species that have already gone extinct in the last two decades. In the U.S., amphibian populations overall are declining at a rate of nearly 4 percent a year, with some areas, such as the Rocky Mountains and the West Coast, facing a higher rate of decline, according to the U.S. Geological Survey.

Although the researchers studied immune gene expression in lowland leopard frogs with chytridiomycosis, the findings may be useful for studying the disease in other frog species due to genetic similarities they share, Savage said.

 

Lowland leopard frogs were chosen for the study because their responses to chytridiomycosis vary from one individual to the next, unlike many other frog species that are completely susceptible to the disease or are completely resistant or tolerant.

This allowed the researchers to rule out genetic variation between species and pinpoint specific differences in lowland leopard frogs’ immune genes that predicted different responses to infection.

The frogs were collected in Arizona and shipped overnight to the Smithsonian’s National Zoo in Washington, D.C., where the infection experiments were conducted. Subsequent analyses of gene expression occurred at the SCBI’s Center for Conservation Genomics. Statistical analyses of the data were performed at UCF.

Robert Fleischer, senior scientist and head of the SCBI’s CCG, co-authored the study and was Savage’s main advisor for the research when she was a postdoctoral fellow at the Smithsonian. Fleischer said the results help in understanding why some frogs survive the disease and others do not.

“If we can solve this mystery, and we have taken a big step in that direction with this study, our hope and plan is to use this information to develop resources and strategies to mitigate the disease in the more susceptible species, and to counter the worldwide tide of extinction and endangerment caused by chytrid,” he said.

The researcher said the findings also show that acquired immune responses, such as those generated by vaccination, may not always be useful in combating invasive diseases of conservation concern.

Brian Gratwicke, a conservation biologist with SCBI; Katherine Hope, an associate veterinarian with the Smithsonian’s National Zoo; and Ed Bronikowski, senior curator of the Smithsonian’s National Zoo, were study co-authors as well.

The research was funded by a Smithsonian Institution Competitive Grants Program for Science grant, the Smithsonian’s Center for Conservation Genomics and a Smithsonian Institution Molecular Evolution Postdoctoral Fellowship.

Anna E. Savage, Brian Gratwicke, Katharine Hope, Edward Bronikowski, Robert C. Fleischer. Sustained immune activation is associated with susceptibility to the amphibian chytrid fungus. Molecular Ecology, 2020; DOI: 10.1111/mec.15533

written by Robert Wells (University of Central Florida)