Download (Atelopus varius), which until recently was thought to be extinct

Researchers confirm the reappearance of the
Harlequin frog in Talamanca, Costa Rica
Rana arlequín. Cortesía de José González-Maya para CRH
The Critically Endangered harlequin frog (Atelopus varius), which until recently was thought to
be extinct following numerous surveys across its former range, has been rediscovered in southern
Costa Rica in the Talamanca Mountains, according to a recent article published by an
international team of researchers.
The harlequin frog was relatively common in areas of Costa Rica and Panama until 1988 when
populations quickly declined like many other species in frogs in the region. Only 6 years later,
the harlequin frog was thought to be extinct – a casualty of the invasive and infectious chytrid
fungus implicated in the extinction of hundreds of amphibian species globally.
Scientists continued to look for the harlequin frog for 10 years when 2 individuals were located
in an inaccessible are near Manuel Antonio National Park, but they have not been seen since
YEAR. A handful of other individuals of this once common frog have been found on expeditions
to remote areas in Panama.
“We have been studying this population of harlequin frogs since 2009. Fortunately, it is located
in a private reserve in the very south of Costa Rica, where access can be controlled to protect
their habitat. After several years of monitoring we found that this population is healthy and
shows no signs of infection by the aggressive chytrid fungus,” explained José González-Maya,
lead author of the report and Scientific Director of the Sierra to Sea Institute and ProCAT
Conservation.
“The next steps for us are to pull together resources to implement a long term monitoring and
recovery program for the species” says González-Maya, “finding it is only the first step, now we
have the difficult task of ensuring its survival against many odds. As we develop a recovery plan
we will need to bring together local and international partners to build a strong team with
sufficient resources to ensure recovery.”
The research team worked with members of the local community to monitor the population of
more than 100 individuals and confirm that this population is breeding. Using this knowledge,
they also built fences and worked with the local community protect the habitat of the population.
“We wanted to make sure the population is healthy and stable rather than reporting on a single
individual. When the fungus first came through this area, scientists found many individuals of
this species dead along this same river,” said Sarah Wyatt (JOSE??), currently a biodiversity
associate with the Global Environment Facility.
The team continues its efforts to monitor and protect this population and its habitat. This species
is found in multiple conservation breeding programs, so the research team’s first priority is
ensuring the survival and growth of this population in this area.
“I’m particularly excited about finding this population, because based on what we know about
this disease and species going extinct in its wake, this population shouldn’t be here. It provides
hope that there are other populations surviving in other areas,” said Jan Schipper, Adjunct
Professor at Arizona State University and Director of the Sierra to Sea Institute. Schipper then
shared the team’s plan to search surrounding areas to look for other populations and other
species that are still thought to be extinct.
“Finding this population is great news for conservation of harlequin frogs, and it raises a number
of important questions about whether it is a resilient population that developed resistance to the
fungus or whether some individuals simply survived and are now repopulating. Regardless, there
is still much work to be done. Globally more than 1 in 3 amphibians are threatened with
extinction, and better understanding this population will shed light on conservation strategies for
other species,” explained Robin Moore, Conservation Officer for the Amphibian Survival
Alliance, who was not part of the study.
Amphibians are often called the bellwethers of environmental change. Living in water with
sensitive skin, the loss of frogs may be a warning of the damage being done to the environment
that will affect us all.
“Rediscovering this population highlights the importance of the conservation efforts made by
local residents to protect their natural resources, especially the owner of the property where the
harlequin was rediscovered. If their habitat hadn’t been protected, these frogs would never have
had a fighting chance against this disease,” explained Tom Brooks, Chief Scientist of the
International Union for the Conservation of Nature, who was not part of the study.
The research team is also working with the community of researchers around the world who are
working to understand and fight the chytrid fungus. They hope that this population can help
scientists better understand the disease and help conserve other species.
This study was an international effort with researchers from the National Autonomous University
of Mexico (UNAM), University of Mississippi, and the University of Arizona-West working
with the Sierra to Sea Institute and ProCAT Conservation. The study was published in the Dutch
journal Amphibia-Reptilia.