Frog named after Charles Darwin saved from extinction

By Stephen Beech

An endangered species of frog named after Charles Darwin has been saved from extinction - thanks to the London Zoo.

A deadly fungus was threatening to wipe out Darwin’s frog in its native Chile.

But a 7,000-mile rescue mission has resulted in 33 precious new froglets being born at London Zoo, potentially saving the species first discovered by Darwin during his epic voyage on HMS Beagle.

In 1841, French zoologist André Marie Constant Duméril and his assistant Gabriel Bibron described and named the species after Darwin.

The birth of the frogs at London Zoo has been hailed as a "landmark moment" in the ongoing battle to save the species from extinction following the introduction of the deadly chytrid fungus to their native habitat.

The tiny frogs, which are particularly susceptible to the fungus, needed a refuge, while conservationists figured out how to make their forest home safe once more.

The urgent rescue mission, which saw conservationists embark on a 7000-mile expedition last October to a remote island off the coast of Chile to retrieve healthy frogs for safeguarding at London Zoo, was documented by wildlife filmmaker Paul Glynn.

The film "A Leap of Hope" is due to premiere tonight (MONDAY) on YouTube.

After 52 frogs were collected and declared chytrid-free, they traveled in specially designed, climate-controlled boxes on a six-hour boat ride, a 15-hour drive to the capital of Chile, Santiago, and a final flight to Heathrow to make it to their new home at London Zoo.

Ben Tapley, Curator of Amphibians at London Zoo, said: “This is a landmark moment in our work to protect the Darwin’s frog from the devastating impact of chytrid fungus.

“The successful parent-rearing of these froglets is a powerful symbol of hope for the species, highlights what can be achieved when conservationists work together and serves as a critical reminder of the role of our conservation zoo.

“We knew we were embarking on something special - the clock was ticking, and we needed to act quickly if we were going to save these frogs – and capturing this work on film has really cemented just how vital our work is.”

Southern Darwin’s frogs in the Parque Tantauco forests in southern Chile faced devastation in 2023 when surveys confirmed the arrival of chytrid fungus.

That led to a "catastrophic" 90% decline in monitored populations within a year, due to amphibian chytridiomycosis – a disease that has now affected at least 500 amphibian species, making it the most devastating infectious disease recognized by science.

Andres Valenzuela-Sanchez, ZSL’s Institute of Zoology research fellow, said: “By working with partners in Chile, we’re able to safeguard these frogs in their new home at London Zoo, ensuring that this unique species has a fighting chance of recovery.

"These frogs are not only vital for the future of their species but also help us better understand how we can combat chytrid fungus and safeguard other amphibians globally.”

The 33 froglets were carried and brooded by 11 male frogs rescued as part of the mission.

The frogs use a unique strategy to protect and rear their tiny tadpoles, carrying them inside their vocal sacs.

When the female Darwin’s frog lays eggs, these then into tadpoles, which the male Darwin’s frog moves into his vocal sac to develop in safety.

After traveling by boat, plane, and car to London, the fathers – each fully grown yet weighing less than two grams and measuring under three centimeters – continued to carry the tiny tadpoles until they metamorphosed into the next generation of the extraordinary species.

With the rearing of the 33 froglets and more soon to follow, London Zoo hopes that its population of Southern Darwin’s frogs will grow from strength to strength, supporting reintroduction efforts in Chile, while helping scientists understand how to counter the devastating chytrid fungus.