Feb 7

North America’s bats are dying in record numbers from white-nose syndrome, a deadly fungus which is spreading across the United States and into Canada.

Photo of Indiana bats hibernating

The Indiana bat, already classified as Endangered due to a range of threats, is one of the species most under threat from white-nose syndrome.

Greatest threat to bats 

First identified in 2006, white-nose syndrome is a fatal disease which infects the skin of hibernating bats, turning their snout frosty white. It is unclear exactly how the disease kills the bats, but it is thought to affect their ability to hibernate, causing infected bats to use up their fat reserves.

The disease has already killed over a million bats of at least six different species, including the Indiana bat, little brown myotis, gray myotis and cave bat. In some colonies it has had a shocking mortality rate of 95 percent. Alan Hicks of the New York State Department of Environmental Conservation has described white-nose syndrome as “the gravest threat to bats… ever seen”.

Photo of little brown myotis

The little brown myotis, another hibernating bat which has been affected by white-nose syndrome.

White-nose syndrome’s rapid spread

Since it was first discovered, white-nose syndrome has spread through bat colonies across the eastern United States, and several infected caves have also been identified in Canada. Without urgent action, the disease is likely to spread unchecked into the western states in what the U.S. Fish and Wildlife Service has called the worst wildlife health crisis in memory.

Photo of greater mouse-eared bat at the roost site

The greater mouse-eared bat is one of the European species found to be infected with white-nose syndrome.

The fungus believed to cause white-nose syndrome, Geomyces destructans, has also been recorded in at least five bat species in Europe, and there is evidence to suggest it was first transported to North America by humans. Although it has not yet caused widespread mortality of bats in Europe, it is unclear whether the situation will stay this way.

A deadly but little-known disease

Unfortunately, scientists still know very little about this worrying disease. Hibernating bats typically come together in large, tightly packed groups, which may increase the risk of cross-infection, and humans are also believed to spread white-nose syndrome between caves.

Photo of a pair of gray myotis bats in flight

The gray myotis, or grey bat, is listed as Near Threatened by the IUCN.

Whatever the answers, urgent action is clearly needed. A recent review published in Conservation Biology has called for the creation of a ‘road map’ to tackle the disease. It concluded that white-nose syndrome has “changed the focus of bat conservation in North America”, and that a national response is required. This may include monitoring and disease surveillance, active research into how to treat individual bats, and a programme of public education.

Others have also called for the urgent closure of caves and mines in the western United States, to prevent visitors from inadvertently helping this deadly fungus to spread even further.

Read The Independent article on this story.

View more bat species on ARKive.

Liz Shaw, ARKive Species Text Author