A Southern Darwin's frog after changing from a tadpole to a froglet. ZSL/Benjamin TapleyShareFollowing a 7,000-mile-long rescue mission for conservation, 33 tiny Southern Darwins frogs (Rhinoderma darwinii) were born at London Zoo. This species is particularly susceptible to the deadly chytrid fungus, currently impacting their native habitat in the forests and glades of Argentina and Chile. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.In October 2024, conservationists from the Zoological Society of London traveled to a remote part of an island off the coast of Chile. Their mission was to retrieve healthy frogs for safeguarding at the London Zoo. Populations of this species found in the Parque Tantauco forests in southern Chile faced devastation in 2023 with the arrival of chytrid fungus. About 90 percent of monitored populations died within a year due to amphibian chytridiomycosis. This fungal disease affects at least 500 amphibian species and is considered among the most devastating infectious diseases. According to the University of California, Riverside Center for Invasive Species Research, it infects amphibians by latching onto the keratin in the mouthparts of tadpoles and skin of adults.The growth of the fungus eventually causes the skin to slough off and amphibians to lose weight, become lethargic and die. Outbreaks have been reported in parts of Australia, Central and North America, Europe, and Asia since it was first documented in the late 1990s.Infected amphibians lose weight, become lethargic, and die. CREDIT: University of California, Riverside. By working with partners in Chile, were able to safeguard these frogs in their new home at London Zoo, ensuring that this unique species has a fighting chance of recovery, Andres Valenzuela-Sanchez, ZSLs Institute of Zoology research fellow, said in a statement. 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.Naturalist Charles Darwin described this tiny, green frog species in 1834, during his voyage on the HMS Beagle. As adults, they weigh less than an ounce and are only about an inch long. They primarily survive on insects and small arthropods. Southern Darwins frogs are known for a unique brooding strategy to protect and rear their tiny tadpoles. The males carry the tadpoles in vocal sacs. Along with seahorses, the frogs are among the few living vertebrates in which dads carry babies in special sacks that make them appear pregnant.The species was described in 1834 by Charles Dawrin. CREDIT: ZSL/Joe Capon. The 33 new froglets were carried and brooded by 11 rescued male frogs. The adult frogs were transported 7,000 miles from Chile to England, while protecting their precious tadpoles until they metamorphosed into froglets.The team hopes that these new froglets will help the population of Southern Darwins frogs grow. The groups efforts are also chronicled in a documentary by wildlife filmmaker Paul Glynn called A Leap of Hope.[ Related: Fungus-infected zombie spiders discovered in Northern Ireland. ]Documenting this journey and the discovery of these incredible frogs has been such a rewarding experience, Ranita de Darwin NGO conservationist Bastin Santana said in a statement. The film captures not only the urgency of conservation workacting quickly to save the worlds most vulnerable speciesbut its a crucial tool to raise awareness of threats amphibians currently face in the wild. Its a story of action and resilience that we hope will inspire others to support amphibian conservation.You can watch A Leap of Hope on YouTube.