Oct 28

Scientists have confirmed that the disease killing bats across North America, known as white-nose syndrome (WNS), is caused by a fungus.

Little brown myotis image

Little brown myotis (Myotis lucifugus)

Deadly fungus

The disease, first discovered in a New York cave in 2006, is now believed to have killed over a million little brown myotis bats in North America. The fungus, Geomyces destructans, grows on the bats’ noses, ears and wings while they are hibernating, causing them to become restless and use up their vital winter fat reserves. It also causes heavy damage to the wings, which play a crucial role in water balance and blood pressure regulation in hibernating bats.

Although scientists already suspected the fungus to be the main cause of WNS, it has not been proven until now. By infecting healthy little brown myotis bats with cultured fungus spores, scientists were able to prove the direct link between the fungus and the disease. They also showed that the fungus is spread by direct contact between bats, rather than by air.

Gray myotis image

The gray myotis appears to be immune to the disease

The future for North America’s bats

White-nose syndrome is believed to have originated in Europe, where bats appear to be immune. Some species in North America, such as the gray myotis, have also shown resistance to the disease. Scientists are hoping to understand why certain species are immune and use this to save others that are susceptible to the fungus.

Now that the fungal pathogen has been confirmed as the cause of WNS, recommendations have been made in order to slow its spread. By closing caves to people and decontaminating anyone visiting a hibernation cave, it is hoped that transmission by humans can be reduced.

Daubenton's bat image

Daubenton's bat hibernating

UK’s bats on the increase

A more positive outlook has been predicted for bat species in the UK, with a recent survey by British Waterways indicating a 9% increase in bats spotted over rivers and canals. Ecologists at the organisation are also predicting that the coming cold winter will be good for bats, helping them to hibernate properly.

Bats, such as Daubenton’s bat, use canals and rivers in order to hunt, flying low over the water to capture insects. An ecologist for the organisation responsible for the survey reiterated the importance of waterways for UK bat species:

Canals and rivers are a bit like supermarket shopping aisles for bats, and having spent the autumn using these corridors to travel and feed, bats should by now have stored up as much fat as they can, ready for the cold.

Read more on the white-nose syndrome story at the BBC – Bat killer cause confirmed as fungus.

Read about the recent UK bat survey in the Guardian – UK bat numbers on the up.

View images and footage of bats on ARKive.

Becky Moran, ARKive Species Text Author