
The young Darwin’s frogs are just millimetres long, and have a unique survival strategy.
When they are tadpoles, their fathers carry them inside their vocal sacs for safety.
But their habitat in the forests of south America is now under threat from a deadly fungus, which is particularly dangerous to the tiny frogs.
So in October, conservationists embarked on an urgent rescue mission to the Parque Tantauco forests on a remote island off the coast of Chile.
They hoped to bring healthy father frogs back to London Zoo for safeguarding while conservationists figure out how to make their forest home safe once more.
The team trekked through the cold, moss-covered forests of Tantauco Park for hours each day, trying to spot the tiny green frogs among the dead leaves under the trees.
Eleven male frogs rescued as part of the mission carried and brooded the 33 froglets.
After travelling by boat, plane, and car to London, the fathers – each fully grown yet weighing less than 2g and measuring under 3cm – continued to carry the precious little tadpoles until they metamorphosed into the next generation of the extraordinary species.
The birth of the young Darwin’s frogs at London Zoo is seen as a huge milestone by conservationists.
The expedition was documented for ZSL, which runs London Zoom by wildlife filmmaker Paul Glynn.
His film, A Leap of Hope, will premiere tonight (February 3) at 6pm on YouTube.
Populations of the Darwin frogs in the Parque Tantauco forests faced devastation in 2023, when the deadly chytrid fungus arrived.
This led to a catastrophic 90% decline in monitored Darwin frog populations within a year, due to amphibian chytridiomycosis – a disease which has now affected at least 500 amphibian species, making it the most devastating infectious disease recognised by science.
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.”
Bastián Santana, from Ranita de Darwin NGO, said the film was a story of “action and resilience that we hope will inspire others to support amphibian conservation”.