In the United States, growing hope of a cure for endangered bats

At the entrance to the longest cave in the world, in the American state of Kentucky, a national parks ranger warns visitors: inside, a fungus is ravaging bat populations. An ecological drama which could soon be stopped, however, scientists hope.

This microscopic fungus causes an infection called white-nose syndrome (WNS) that has killed millions of flying mammals since its arrival in the eastern United States nearly 20 years ago – one of the largest mass die-offs in history. animal species in modern history.

Two decades later, no treatment has been found, but scientists are finally beginning to implement a series of measures aimed at minimizing the impact of the disease.

A source of hope, as the fungus begins to spread in the American West.

“We went from a situation where we had no idea what was happening to a situation where we have a range of effective tools for different places and situations”rejoices Jonathan Reichard, SMB specialist for a federal agency responsible for wildlife preservation.

Among these tools: fumigation of animals and caves to slow the growth of the fungus or spraying in the summer – outside the bats’ hibernation period – with a chemical product, polyethylene glycol 8000, on the walls.

Other promising solutions, such as a vaccine against this fungal infection – are still being tested, adds Michelle Verant, veterinarian for the US National Parks Agency, the NPS.

Thanks to “a lot of different tools” used “in the right place at the right time, we will be able to help a certain number of bats get through the initial phase of the disease”estimates the expert.

Ecological disaster

The syndrome, named because of the white spots it causes around the snout (but also the ears and wings), affects hibernating bats, waking them up and forcing them to expend their energy reserves.

In several American caves, bats have been found dead, hanging next to other sick bats or crawling on the ground, the researchers recall.

The first case of infection recorded in Mammoth Cave, Kentucky, dates back to 2013.

The fungus has since continued to grow in the total darkness and cool of its labyrinth of tunnels.

If the disease only affects bats, its repercussions are much broader, scientists warn.

These flying mammals, which feed on insects, play an essential ecological role.

If all the consequences of WNS are not yet understood, a study recently published in the prestigious journal Science links the collapse of bat populations in North America to the growing use of pesticides and the increase in infant mortality among the man.

Silent tragedy

The United States and Canada are home to more than 40 species of bats; the disease mainly affects those that hibernate.

Assessing their numbers is very complicated, but researchers agree that the disease killed more than 90% of northern myotis, Cuvier’s bats and little brown bats – the three species most affected.

This last species was once very present in the territory.

In the immense Mammoth Cave, Indiana bats are also affected by the disease, explains Rick Toomey, a researcher and park manager.

However, this tragedy goes almost unnoticed. When they come for a tour of the cave, many visitors are unaware of the very existence of this disease.