Category Archives: reintroduction

Following reintroduced frogs

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The Panama Amphibian Rescue and Conservation Project completed the first reintroduction trial of the Limosa Harlequin frog (Atelopus limosus) in 2017, and our findings were published in the journal Frontiers in Amphibian and Reptile Science. Reintroducing a species comes with a lot of unknowns and questions, just a few are: Where will the frogs go? What is their life like outside of a terrarium? Will they become infected with amphibian chytrid fungus? The purpose of this first reintroduction trial was to begin to unravel some of these questions so the researchers could adapt their strategies and improve the odds of the frogs in the wild.

We were able to get a detailed life of the frogs post-reintroduction by radiotracking the frogs and checking in on them daily. We found that when frogs were provided a 30-day acclimation period in a predator-free rainforest mesocosm, their probability of survival significantly increased and they did not disperse as far as the hard-released animals. We know from other studies that more movement can increase the likelihood of predators finding animals, and that likely happened in this study too. Frogs that were released without radio transmitters were 44x less likely to be reencountered during stream surveys (finding a frog in the rainforest isn’t easy!). We were able to follow the lives of these frogs in the wild for up to 56 days after release and developed a method that can use both radio-tracked animals and non-radiotracked animal encounters to estimate survivorship by assigning different detection probabilities in the model.

We observed a couple predation events of reintroduced frogs and some became infected with amphibian chytrid fungus. However, we learned a lot and has no shortage of questions to continue researching to get this species (and others in Panama) back into the wild.

Read the open access paper here:
Klocke, B., Estrada, A., Mataya, M., Medina, D., Baitchman, E., Belden, L., Guerrel, J., Evans, M., Baughman, J. and Connette, G., Illueca, E., Ibáñez, R., Gratwicke, B. (2023) Movement and survival of captive-bred Limosa Harlequin frog (Atelopus limosus) released into the wild. Frontiers in Amphibian and Reptile Science, 1, p.1205938. https://doi.org/10.3389/famrs.2023.1205938 

by Blake Klocke

First release trial of Atelopus limosus shows that animals rapidly recover a wild-type skin microbiome.

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In 2017, Virginia Tech PhD students Angie Estrada and Daniel Medina conducted the first release trial of captive-bred Limosa Harlequin frogs at the Mamoni Valley Preserve. Their study aimed to closely observe how 1-year-old captive-bred animals would transition from captive conditions back into the wild. To soften the blow of the changing conditions, and to allow the researchers to capture the frogs again, they designed 30 square shaped mesocosms from plastic mesh. In reintroduction biology placing animals in a temporary field enclosure prior to release is known as a soft release. They filled the bottom layer with leaf litter collected from the forest floor that was rich in leaf-litter invertebrates, a diet quite different from the crickets and fruit-flies they are usually fed by staff at the Panama Amphibian Rescue and Conservation Center. Each mesocosm housed a single animal that was monitored daily  for a month and weighed and swabbed weekly.

It is known that captivity can alter skin microbiomes of amphibians and other captive animals, and that this is an important component of amphibian immune defenses. This study found that wild and captive Atelopus limosus had very different microbiomes, but that after a month living in mesocosms, the skin microbiome had rapidly changed to resemble the microbiome of wild individuals. One concern about bringing animals into captivity for prolonged periods is that animals might lose symbiotic microbes that help them to survive in the wild, which might reduce the fitness of captive-bred animals, but this study found that the skin microbiome was rapidly rewilded.

The mesocosms were a useful tool that protected the animals from larger predators, though one was killed by army ants. Female animals lost body condition more rapidly than males, but at the end of the trial their condition resembled that of wild-caught animals. About 15% of the animals became infected with the amphibian chytrid fungus in the first month compared to 13-27% Bd prevalence in wild amphibian community.

Estrada, A., Medina, D; Gratwicke, B, Ibáñez, R, Belden, L (2022) Body condition, skin bacterial communities and disease status: Insights from the first release trial of the Limosa harlequin frog, Atelopus limosus. Proceedings of the Royal Society B. https://doi.org/10.1098/rspb.2022.0586

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/

Update from Release trial Research at Centro Mamoni

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Blake Klocke, a student at George Mason University is studying where frogs go once we release them, how long it takes them to contract the chytrid fungus, if there are any effects of releasing chytrid susceptible frogs on the existing frog community & what other non chytrid fungus sources of mortality might affect reintroduction work.

In addition to our primary project partners the Houston Zoo, Zoo New England and the Cheyenne Mountain zoo we thanks the National Geographic Society, Mohammed Bin Zayed Species Conservation Fund, and the Smithsonian Women’s Committee for their support of these release trials.

Variable Harlequin Frog release trials begin in Panama

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Once common along highland streams from western Costa Rica to western Panama, the variable harlequin frog is endangered throughout its range, decimated by a disease caused by the amphibian chytrid fungus. On Jan. 17, Smithsonian researchers released approximately 500 frogs at Cobre Panama concession site in Panama’s Colon province as a first step toward a potential full-scale reintroduction of this species. This release trial is included in Cobre Panama’s biodiversity conservation plan as an important part of their environmental commitments.

Composite image showing variation in coloration within this population of frogs

The variable harlequin frog, Atelopus varius, takes its name from the variety of neon colors—green, yellow, orange or pink—juxtaposed with black on its skin. In order to monitor the released frogs over time, 30 are wearing miniature radio transmitters. The scientific team also gave each frog an elastomer toe marking that glows under UV light to mark individuals as part of a population monitoring study.


“Before we reintroduce frogs into remote areas, we need to learn how they fare in the wild and what we need to do to increase their chances of survival in places where we can monitor them closely,” said Brian Gratwicke, international coordinator of the Panama Amphibian Rescue and Conservation project (PARC) at the Smithsonian Conservation Biology Institute. “Release trials may or may not succeed but the lessons we learn will help us to understand the challenges faced by a frog as it transitions from captivity into the wild.”

Heidi Ross and her team at our facilities in the Nispero Zoo successfully bred and reared these animals for the release trial

Variable harlequin frogs are especially sensitive to the amphibian chytrid fungus, which has pushed frog species to the brink of extinction in Central America. PARC brought a number of individuals into the breeding center between 2013 and 2016 as chytrid continued to impact wild populations.

 

The field team all assembled with frogs ready for the release trial

“The variable harlequin frog is one of the closest relatives of Atelopus zeteki, Panama’s iconic golden frog, another target species in our captive breeding program,” said Roberto Ibañez, PARC project director at the Smithsonian Tropical Research Institute in Panama. “We’ll be monitoring the surrounding amphibian community and the climate at this site, and comparing this to the amphibian community at another, control site. This kind of intensive monitoring will help us to understand disease dynamics in relation to the release trials”

One of our Atelopus varius wearing a mini radio-transmitter

PARC hopes to secure the future for this and other endangered amphibians by reintroducing animals bred in captivity according to an action plan developed with Panama’s Ministry of the Environment and the International Union for the Conservation of Nature (IUCN) and other stakeholders. “It took us several years to learn how to successfully breed these frogs in captivity,” said Ibañez. “As the number of individuals we have continues to increase, it provides new research opportunities to understand factors influencing survival that will ultimately inform long-term reintroduction strategies.”

The PARC project thanks Cobre Panama, National Geographic Society, Mohammed bin Zayed Species Conservation Fund and The WoodTiger Fund for their generous support.

PARC is a partnership between the Cheyenne Mountain Zoo, the Houston Zoo, the Smithsonian Tropical Research Institute, the Smithsonian Conservation Biology Institute and Zoo New England. It has two facilities in Panama: the Gamboa Amphibian Rescue and Conservation Center at STRI and the El Valle Amphibian Conservation Center at El Nispero. Combined, these facilities have a full-time staff caring for a collection of 12 endangered species.

SCBI plays a leading role in the Smithsonian’s global efforts to save wildlife species from extinction and train future generations of conservationists. SCBI spearheads research programs at its headquarters in Front Royal, Va., the Smithsonian’s National Zoo in Washington, D.C., and at field research stations and training sites worldwide. SCBI scientists tackle some of today’s most complex conservation challenges by applying and sharing what they learn about animal behavior and reproduction, ecology, genetics, migration and conservation sustainability.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a unit of the Smithsonian Institution. The Institute furthers the understanding of tropical biodiversity and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.

The Smithsonian Tropical Research Institute and Panama’s Ministry of the Environment (MiAmbiente) Participate in Frog Release Trials in Eastern Panama as Part of the Implementation of the Action Plan for the Conservation of Amphibians in Panama

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Scientists from the Smithsonian Tropical Research Institute (STRI) and officials from Panama’s Ministry of the Environment (MiAmbiente) visited the Mamoní Valley Reserve, where release trials are underway to release Limosa Harlequin (Atelopus limosus) frogs. These frogs were bred in captivity and are the descendants of frogs collected a few years ago in the same area.

MiAmbiente was represented by biologists Erick Núñez and Anthony Vega, technicians from the Department of Biodiversity of the Office of Protected Areas and Wildlife. They were accompanied by STRI staff scientist Roberto Ibáñez, director of the Panama Amphibian Rescue and Conservation Project (PARC), and Juan Maté, STRI’s manager for scientific affairs and operations and institutional liaison with MiAmbiente. PhD student at the Smithsonian-Mason School of Conservation at George Mason University, Blake Klocke, who is currently conducting this research, hosted and guided this visit, together with his field assistant, Mirjana Mataya.

Some of the frogs are from the initial release trial conducted in the El Valle del Mammoní Reserve by Panamanian PhD students from Virginia Tech, Daniel Medina and Angie Estrada. They kept the frogs inside enclosures in this reserve to protect them from predators and so that they could obtain samples to determine if they were infected by the chrytrid fungus (Batrachochytrium dendrobatidis). In a second release trial, Blake Klocke freed these and additional frogs. In this phase of the investigation, one of the objectives is to determine if it is necessary to keep in enclosures before releasing them completely. Some of the frogs were equipped with radio transmitters that allow researchers to follow their movements and estimate the size of their territories.

The visit with MiAmbiente officials was aimed at monitoring the release trials and the progress of research. Blake Klocke showed them how the radio-telemetry tracking system works using mini-transistors. This technological tool, applied to scientific research, allows us to follow the movements of these small frogs. Frogs without radio transmitters were certainly harder to observe. Likewise, measurements of the size and weight of frogs were obtained and samples of their skin were collected with swabs for detection of the chytrid fungus. At this point, the frogs have been kept close to the point of release. However, based on the data being collected, researchers will be able to estimate the future dispersion and survival of the frogs.

The initiative to advance the release trials is part of the Panama Amphibian Rescue and Conservation Project, known colloquially as PARC and administered by the Smithsonian Tropical Research Institute under the supervision of MiAmbiente. This project is a collaboration among several organizations including Cheyenne Mountain Zoo, Houston Zoo, Smithsonian National Zoological Park and New England Zoo. It has been supported by a long list of sponsors, among them Minera Panama SA.
PARC has two facilities, one at El Níspero Zoo in El Valle de Antón, Coclé, now known as PARC El Valle and the other in Gamboa in the Panama Canal Watershed, known as PARC Gamboa. The PARC El Valle facility received the first rescued frogs, which had been temporarily kept at the Hotel Campestre in 2007, an initiative of the El Nispero Zoo and the Houston Zoo, with funding from the latter as an emergency response to the reduction in numbers of amphibians due to the mortality caused when the fungus arrived in El Valle de Antón in 2006. In 2009, this facility in El Valle came under the umbrella of the PARC project, and has continued its operation within the El Níspero Zoo. In addition, in 2009, PARC Gamboa initially began with the building of facilities at Summit Municipal Park, before relocating to its current location in Gamboa in 2012 to improve and expand capacity for ex-situ conservation of amphibians and create an additional backup at a second site. The PARC project is characterized by the result of the joint effort of multiple organizations and large numbers of people who, over the years, have contributed to the conservation of Panama’s amphibians.

MiAmbiente and the STRI have an inter-agency collaborative agreement under which they work closely on the implementation of the Amphibian Conservation Action Plan in Panama approved in 2011. The Plan aims to ensure the conservation of amphibian populations through the implementation of actions that promote research and management, both in situ (in their habitat) and ex situ (outside their habitat) in addition to promoting the education of society in general. This plan integrates specific research, conservation and education activities in the short and medium term with the goal of safeguarding our natural heritage.

This visit served as a joint verification by STRI and MiAmbiente on the progress of the project. An important milestone has been reached in the implementation of this Action Plan, as this is the first time in Panama that an amphibian conservation project is executing the phase where the behavior and survival of frogs reared in captivity is being investigated by exposing the animals to their natural environment. The results of these release trials will be of great use in guiding future efforts to re-establish the populations of certain species of frogs at sites where they have decreased in abundance or disappeared.

First Release Trial to Help Pave the Way for Reintroduction Programs for Critically Endangered Frogs

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Ninety Limosa harlequin frogs (Atelopus limosus) bred in human care are braving the elements of the wild after Smithsonian scientists sent them out into the Panamanian rainforest as part of their first-ever release trial. The study, led by the Panama Amphibian Rescue and Conservation Project, aims to determine the factors that influence not only whether frogs survive the transition from human care to the wild, but whether they persist and go on to breed.

“Only by understanding the trials and tribulations of a frog’s transition from human care to the wild will we have the information we need to someday develop and implement successful reintroduction programs,” said Brian Gratwicke, international program coordinator for the rescue project and Smithsonian Conservation Biology Institute (SCBI) amphibian conservation biologist. “Although we are not sure whether any of these individual frogs will make it out there, this release trial will give us the knowledge we need to tip the balance in favor of the frogs.”

The Limosa harlequin frogs released at the Mamoní Valley Preserve, have small numbered tags inserted under their skin so that researchers can tell individuals apart. The scientific team also gave each frog an elastomer toe marking that glows under UV light to easily tell this cohort of frogs apart from any future releases. Smithsonian-Mason School of Conservation Ph.D. student Blake Klocke is currently monitoring the frogs daily at the site, collecting information about survivorship, dispersal, behavior and whether the warm micro-climate in the area provides any protection against disease.

The study is also looking at whether a “soft release” boosts the frogs’ ability to survive. Thirty of the newly released frogs spent a month at the site in cages, acclimating to their surroundings and foraging on leaf-litter invertebrates. Eight of these frogs, and eight that were released without the trial period, are wearing miniature radio transmitters that will give Klocke and team a chance to look at differences in survival and persistence between the two groups. The researchers also collected skin bacteria samples from the soft release frogs to measure changes during their transition from captivity to the wild.

“The soft release study allowed us to safely expose captive-bred frogs to a more balanced and varied diet, changing environmental conditions and diverse skin bacteria that can potentially increase their survival in nature,” said Angie Estrada, Ph.D. student at Virginia Tech and a member of the team leading the soft release, which was funded through a Smithsonian Tropical Research Institute (STRI) grant and support from the National Science Foundation. “It allowed us to monitor health and overall body condition of the animals without the risk of losing the frogs right away to a hungry snake.”


Limosa harlequin frogs are especially sensitive to the amphibian chytrid fungus, which has pushed frog species to the brink of extinction primarily in Central America, Australia and the western United States. The Panama Amphibian Rescue and Conservation Project brought a number of individuals into the breeding center between 2008 and 2010 as chytrid swept through their habitat. The Limosa harlequin frogs in this release trial are the first captive-bred generation of the species, and only part of the rescue project’s total insurance population for the species.

“After all the work involved in collecting founder individuals, learning to breed them, raising their tadpoles, producing all their food, and keeping these frogs healthy, the release trial marks a new, exciting stage in this project,” said Roberto Ibáñez, in-country director of the rescue project and STRI scientist. “These captive-bred frogs will now be exposed to their world, where predators and pathogens are ever-present in their environment. Their journey will help provide the key to saving not only their own species, but Panama’s other critically endangered amphibian species.”

The Panama Amphibian Rescue and Conservation Project is a project partnership between the Cheyenne Mountain Zoo, the Houston Zoo, Zoo New England, the SCBI and STRI. This project received additional support from the Friends of the National Zoo, Holohil, The Woodtiger Fund, Mamoni Valley Preserve and Earth Train.

SCBI plays a leading role in the Smithsonian’s global efforts to save species from extinction and train future generations of conservationists. SCBI spearheads research programs at its headquarters in Front Royal, Va., the Smithsonian’s National Zoo in Washington, D.C., and at field research stations and training sites worldwide. SCBI scientists tackle some of today’s most complex conservation challenges by applying and sharing what they learn about animal behavior and reproduction, ecology, genetics, migration and conservation sustainability.