Conservation milestone: Darwin's first froglets born in London

December 6th marked an exciting milestone in the conservation of Darwin's Frog ( Rhinoderma darwinii ). Two recently metamorphosed froglets emerged from the vocal sac of a pregnant male, brought from Chile with developing tadpoles.

Juvenile Darwin's frog — First Darwin’s Frog Born at ZSL (Zoological Society of London) from a Pregnant Male Originally from Tantauco. © ZSL (Zoological Society of London)

This event, which took place at the ZSL (Zoological Society of London) facility, symbolises a crucial step forward in international efforts to save this critically endangered species. Just days later, on 9 December, two additional males released four more froglets, bringing the total number of births at the zoo to six.

Juvenile green Darwin frog in terrarium — One of the Darwin’s Frogs Born at ZSL in December 2024 © ZSL (Zoological Society of London)

And there’s more to come! With several pregnant males still in ZSL’s care, up to 24 new froglets are expected to be born in the coming weeks – an encouraging sign for this species whose future is in jeopardy due to the threat of chytridiomycosis, a deadly disease caused by a fungus.

An Extraordinary Journey to Protect a Species

The transfer of these frogs from Chile to London was made possible thanks to a collaborative effort between the NGO Ranita de Darwin, the Andrés Bello University, Tantauco Park, ZSL, the Leipzig Zoo, the National Zoo of Chile and the University of Concepción. In 2023, the Darwin's Frog populations in Tantauco Park, their most important refuge, were devastated by the arrival of chytridiomycosis. More than 1,300 specimens succumbed to the fungus in less than a year, underlining the urgency of acting to avoid extinction.

People being rescued in front of a small plane in Chiloé — Emergency Working Group During the Rescue of Darwin’s Frogs in Tantauco, October 2024..

ZSL, which has been leading research into chytridiomycosis for 17 years, was selected as the ideal destination to house these frogs due to its expertise in amphibian conservation and its ability to conduct ex situ breeding programs.

Leaders in Darwin's Frog Conservation in London

ZSL Curator of Amphibians and Reptiles Ben Tapley and Ranita de Darwin NGO President and ZSL Researcher Andrés Valenzuela-Sánchez are co-leading this captive breeding project.

Ben Tapley taking samples from Darwin's frogs for chytridiomycosis at ZSL's London Zoo — Ben Tapley and Team, Collecting Samples from Darwin’s Frogs for Chytridiomycosis Detection © ZSL (Zoological Society of London)

Ben Tapley is internationally recognised for his work on amphibians and reptiles, collaboration on initiatives such as ZSL’s EDGE programme, and serving as co-chair of the IUCN Amphibian Specialist Group’s ex situ breeding group. Andrés is co-chair of the IUCN Amphibian Specialist Group’s communications and education group and brings his expertise in amphibian research and conservation, forging an essential bridge between field activities in Chile and ex situ conservation efforts in London.

Andrés giving a talk at the Natural History Museum

Andrés Valenzuela Sánchez working in the field — Andrés Valenzuela-Sánchez is a ZSL Researcher, President of our NGO, and Co-leader of the Ex Situ Breeding Project for Darwin’s Frogs in London. © ZSL (Zoological Society of London)

Ben recently presented this collaborative effort at ZSL’s annual Science and Conservation conference, an internal event of this organization that brings together science, conservation and policy departments to share experiences and progress from different projects.

Ben Tapley Presents Emergency Frog Rescue Project to People

Ben Tapley Presents Emergency Frog Rescue Project to People. Slide shows people on the ground

Ben Tapley presents emergency frog rescue project to people. Slideshow shows Darwin's frogs

Ben Tapley presents emergency frog rescue project to people. Slideshow shows facilities at London Zoo

Ben Tapley presents the emergency frog rescue project to people. Slide shows the logos of the collaborators, Darwin NGO frog, Tantauco Park, Leipzig Zoo, Andres Bello University, Concepcion University, National Zoo, ASG, Rhinoderma Strategy — Ben Tapley Presenting the 'Tantauco Rescue' Collaborative Effort at ZSL’s Annual Science and Conservation Conference. © ZSL (Zoological Society of London)

A Future with Hope

The birth of these six froglets marks a significant step in the fight to protect Darwin's frog. However, the work is far from over. Births are expected to continue in the coming weeks, providing hope for a species facing serious challenges.

This achievement highlights the importance of international collaboration and ex situ breeding programmes to protect endangered species. With each little frog born in London, we come a step closer to ensuring the survival of this iconic Chilean amphibian.

Thank you for reading Conservation Milestone: Darwin’s First Froglets Born in London.

We would like to thank The Mohamed bin Zayed Species Conservation Fund, The Weeden Foundation and The IUCN SSC Amphibian Specialist Group ( ASG ) for their support in this Project.

To join our conservation community you can check: https://www.ranitadedarwin.org/en/adoptaranitadedarwin