Release trial of captive-bred variable harlequin frogs Atelopus varius shows that frogs disperse rapidly, are difficult to recapture and do not readily regain skin toxicity
Blake Klocke,
Orlando Garcés,
Elliot Lassiter,
Jorge Guerrel,
Andreas Hertz,
Estefany Illueca,
Eric Klaphake,
Luke Linhoff,
Kevin Minbiole,
Heidi Ross,
Julia A. Tasca,
Douglas C. Woodhams,
Brian Gratwicke,
Roberto Ibáñez
Affiliations
Blake Klocke
Smithsonian's National Zoo and Conservation Biology Institute, Center for Species Survival, Front Royal, Virgina, USA Department of Environmental Science and Policy, George Mason University, Fairfax, Virgina, USA
Smithsonian Tropical Research Institute, Panama Amphibian Rescue and Conservation Project, Gamboa, Panama
Elliot Lassiter
Smithsonian Tropical Research Institute, Panama Amphibian Rescue and Conservation Project, Gamboa, Panama
Jorge Guerrel
Smithsonian Tropical Research Institute, Panama Amphibian Rescue and Conservation Project, Gamboa, Panama
Andreas Hertz
Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, USA
Estefany Illueca
Smithsonian Tropical Research Institute, Panama Amphibian Rescue and Conservation Project, Gamboa, Panama
Eric Klaphake
Cheyenne Mountain Zoological Society, Colorado Springs, Colorado, USA
Luke Linhoff
Smithsonian's National Zoo and Conservation Biology Institute, Center for Species Survival, Front Royal, Virgina, USA
Kevin Minbiole
Department of Chemistry, Villanova University, Villanova, Pennsylvania, USA
Heidi Ross
Smithsonian Tropical Research Institute, Panama Amphibian Rescue and Conservation Project, Gamboa, Panama El Valle Amphibian Conservation Foundation, El Valle de Antón, Panama
Julia A. Tasca
Department of Chemistry, Villanova University, Villanova, Pennsylvania, USA Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
Douglas C. Woodhams
Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, USA
Department of Environmental Science and Policy, George Mason University, Fairfax, Virgina, USA Sistema Nacional de Investigación, SENACYT, Clayton, Panama
Variable harlequin frogs Atelopus varius have declined significantly throughout their range as a result of infection with the fungal pathogen Batrachochytrium dendrobatidis (Bd). The Panama Amphibian Rescue and Conservation Project maintains an ex situ population of this Critically Endangered species. We conducted a release trial with surplus captive-bred A. varius individuals to improve our ability to monitor frog populations post-release, observe dispersal patterns after freeing them into the wild and learn about threats to released frogs, as well as to determine whether natural skin toxin defences of frogs could be restored inside mesocosms in the wild and to compare Bd dynamics in natural amphibian communities at the release site vs a non-release site. The 458 released frogs dispersed rapidly and were difficult to re-encounter unless they carried a radio transmitter. No frog was seen after 36 days following release. Thirty frogs were fitted with radio transmitters and only half were trackable by day 10. Tetrodotoxin was not detected in the skins of the frogs inside mesocosms for up to 79 days. Bd loads in other species present at sites were high prior to release and decreased over time in a pattern probably driven by weather. No differences were observed in Bd prevalence between the release and non-release sites. This trial showed that refinements of our methods and approaches are required to study captive Atelopus frogs released into wild conditions. We recommend continuing release trials of captive-bred frogs with post-release monitoring methods, using an adaptive management framework to advance the field of amphibian reintroduction ecology.
