White-nose syndrome has killed millions of bats since it was first discovered in the U.S. Northeast in 2006. Biologists consider it North America’s worst-ever wildlife disease outbreak. It not only threatens to drive some bat species extinct — it could also cause significant insect pest problems.

Every year bats provide billions of dollars’ worth of free pest control by eating tons of insects that attack crops and trees. Without bats, farmers and foresters may use more pesticides. That’s costlier and harms the environment. Bat poop is also an essential source of nutrients in cave environments supporting salamanders, fish, crayfish and other unique creatures.

In less than a decade, the previously unknown  disease dubbed white-nose syndrome — for the characteristic white fuzz it causes on bats' noses and wings — has spread from coast to coast, and is killing bats in 34 U.S. states and seven Canadian provinces. At least 13 species have so far proven susceptible to the disease. Some are moving toward extinction: combined with other threats, the disease may overwhelm their ability to recover.

Affected bat colonies have declined by as much as 99 percent — some even greater. Some species in parts of the Northeast, like the once-common little brown bat, are almost gone. Scientists predict the federally listed Indiana bat will decline to less than 14 percent of its pre-white-nose syndrome numbers by 2022.

The disease strikes bats during hibernation, when their immune systems are lowered and they must survive on limited fat reserves for months. Infected bats arouse more frequently from their hibernation, burning off much more fat. They may also suffer from severe dehydration and electrolyte imbalances.

Possible white-nose syndrome treatments range from anti-fungal agents to vaccines, but field trials aren’t yet underway. Widespread application of any treatment is years away. Meanwhile, with their low reproductive rate and limited ability to rebound from population crashes, bats face many other threats that could wipe out any survivors. These threats include industrial wind-energy projects, habitat loss to logging, oil and gas extraction and mining, and environmental toxins.

There’s important work to do to ensure bats have a chance to survive white-nose syndrome and everything else that threatens them.


Although the exact origins of white-nose syndrome are unclear, there's strong evidence it came to North America from Europe. After its outbreak in North America, researchers discovered the fungus exists in Europe but doesn’t kill bats. They later also identified it in several parts of China, where bats likewise apparently suffer no ill effects. This suggests the fungus has been in Europe and at least parts of Asia for a very long time.

White-nose syndrome was first discovered in North America in a cave complex often visited by people in upstate New York in February 2006. Since bats don't travel between Europe and North America, the most likely explanation for the appearance of the bat-killing fungus is that it was transported on the gear, clothing or footwear of a cave visitor travelling between continents.

Research indicates the white-nose fungus can survive indefinitely in places like caves. It can even grow, if slowly, in a diversity of substrates without bats or even much organic matter. That means infected caves and mines in North America may be permanent sources of contamination.

In March 2016 the discovery of white-nose syndrome in western Washington — a jump of 1,300 miles from the next closest location — dashed hopes of keeping the bat malady out of the West. The origins of this new disease epicenter are likely a human-assisted transmission, so it remains vital that people do all they can not to hasten the spread of white-nose syndrome around the West any further. We need to give bats a better chance of holding on until scientists develop an effective treatment.


The Center has taken crucial steps to safeguard affected bat species, like the northern long-eared bat and eastern small-footed bat, which we petitioned to protect under the Endangered Species Act in 2010.

The potential for human transfer of the white-nose fungus — and the need to do everything possible to reduce the risk of this form of disease spread — has been a major focus. We’ve called for stricter rules on cave recreation on public lands and intervened in habitat-harming projects like strip mining, oil and gas drilling and pipeline construction that would further threaten at-risk bats.

It's vital that we curtail the spread of white-nose syndrome and save millions more bats. We need your help. You can start today — join the Center's Save Our Bats campaign by signing in at the top of this page, write a letter to the editor of your local newspaper, and/or like our Facebook page and share it with your friends and family.

Bat photo by Marvin Moriarty, USFWS; Save Our Bats logo by Kimberly Daly,