More than thirty years ago, amphibian researchers from around the world gathered in Canterbury, England, for the first World Herpetology Congress and, over drinks, shared the same chilling story.

Frogs were disappearing in the wild and no one could explain why.

It was “a scary time,” recalls Australian veterinarian Lee Berger, who in the 1990s was one of the first to identify the culprit: a waterborne chytrid fungus known as Batrachochytrium dendrobatidis, Or comics.

Scientists now know that this stealthy threat originated in East Asia and likely inadvertently spread to every continent except Antarctica.

The parasitic fungus can be as transmissible as it is deadly, wiping out entire populations of some frogs within weeks. And until recently, it has proven largely unstoppable. Despite more than 25 years of intense study, environmental advocates have not found a panacea capable of preventing comics infections or save populations of frogs after contracting the comics-caused by a skin disease, chytridiomycosis.

comics has been implicated in the decline and possible extinction of around 200 species of frogs.

Yet today, Berger and other researchers see reason for optimism. There is evidence that some frogs naturally evolving resistance. Scientists are also trying to exploit the fungus’ sensitivity to temperature by constructing comics-free habitats or the movement of frogs to places where the fungus cannot survive. Still others study viruses that attack comics and could possibly be used to reduce its virulence. These innovative strategies emerge as faint glimmers of hope in an otherwise bleak landscape.

Chytridiomycosis kills because the skin is an integral part of the frog’s cardiovascular system. When chytrid fungus colonizes the skin, electrolytes cannot be absorbed. This disrupts the heart’s electrical rhythms and the animals die of heart failure.

But although it is ruthlessly effective at killing some species of frogs, the fungus is very vulnerable to heat: Temperatures above 30 degrees Celsius (about 85 degrees Fahrenheit) slow the progression of the disease.

The armored fog frog of the humid tropics of Queensland, Australia, appears to have altered its habitat, allowing it to take advantage of this fungal Achilles heel. The frog, thought to be extinct for nearly 20 years, no longer lives in shady areas near waterfalls in the forest’s mountains. But a population persists in warmer, sunnier areas. This may be because frogs can rest on sun-baked rocks all night, raising their body temperatures enough to avoid escaping. comicsexplains biologist Conrad Hoskin of James Cook University in Queensland.

Since 2013, Hoskin has been transplanting armored frogs from the surviving population into new, equally sunny habitats and closely monitoring the health of these new colonies.

As part of a larger effort, Hoskin and colleagues recently assessed the habitats of 55 eastern Australian frog species, including 25 affected by comics. They found that although the fungus has reduced the range of affected species, they are persisting in warmer lower elevations with more rain.

Other researchers have also tried to move groups of comics-infected frogs, either to save dying populations or to propagate those that are recovering. Of 15 resettlement attempts in Australia over the past 20 years, seven populations are holding on and three prosper.

Providing amenities for the frogs also helped. Conservation biologist Anthony Waddle of Sydney’s Macquarie University built thermal shelters from large prefabricated bricks with holes that happen to be the perfect size for green and golden frogs. The sick frogs that hung out in these “frog saunas” reduce infection burdens than those who have been convalescing in the shade, Waddle and colleagues reported in 2024 in Nature.

As this incremental progress continues, scientists are working to understand why certain species of frogs are more susceptible to comics than others. Conservation biologist Tiffany Kosch, who works with Berger in the One Health research group at the University of Melbourne veterinary school, takes a genetic approach. Kosch recently sequenced the genome of the southern corroboree, a black and bright yellow frog of which 50 or fewer survive in the wild. If scientists can learn which particular versions of genes are associated with comics resistance, they could raising and releasing resistant frogsor even engineer comics resistance in the southern corroborés.

Researchers also discovered a fungal virus that appears to infect weaker strains of fungi. comics– pathogens for the pathogen, in other words. While exploiting these viruses to fight against comics is far away, perhaps one day it will be another weapon. “In the science fiction version, you spray the virus on the ground and the frogs all survive – that’s the hope,” says mycologist Jason Stajich of the University of California, Riverside, co-author of a work on science fiction. recent report on the virus In Current biology.

Berger, who co-published a update on Australian frogs and comics in 2024 Annual Review of Animal Biosciencessays that despite losses, optimism is key to conservation work. “You have to make a choice and focus on the positive.”

Indeed, there is still much work to be done to prevent further declines and extinctions, says ecologist Andrea Adams of the University of California, Santa Barbara. “We cannot afford to take a hands-off approach.”