White-nose Syndrome

Michael Barnes
Age of Awareness
Published in
4 min readMar 7, 2020
Little brown bat (Myotis lucifugus) infected with fungus on muzzle, taken by Marvin Moriarty

White-nose syndrome (WNS) is a deadly disease that has had devastating effects on North American bat species over the past 15 years. First appearing in North America in 2006, WNS has spread coast-to-coast, starting in New York and spreading to the west coast in recent years. In 2011, expert bat biologists estimated that 5.7–6.7 million bats had died in the 5 years that WNS had been in North America. Current numbers are unknown, but given the estimates found in 2011 and a mortality rate of 70 to 90 percent, many bat species are in dire trouble unless measures are taken to mitigate this deadly disease.

“Fungi giveth, fungi taketh away.” I wrote this in my article on fungi. Although fungi provide incredible benefits to people and the environment, they also have the ability to cause devastation. WNS is caused by a fungus called Pseudogymnoascus destructans, or Pd for short, that occur in caves where some bats hibernate — not every species of bat hibernates and the ones that don’t, do not typically get WNS. It is believed that Pd came over from Europe where bat species had evolved — over thousands of years — a resistance to the fungus. But how did it get to North America? It’s hard to know, but it’s likely that it was brought over by people. Fungal spores hitch a ride on clothing and equipment, and can wait a long time to find the habitat that they need — sometimes upwards of one month! Once it finds its way to a cave with bats in it, GAME OVER.

When a bat is infected by Pd, the fungus grows on it’s muzzle (or snout) and wings, and turns characteristically white (pictured above), hence the name white-nose syndrome. The ability for the fungus to survive in the cold climate of caves, and a bat’s lowered body temperature makes WNS incredibly deadly. Outside of hibernation, a bat’s body temperature is too high for Pd to establish itself. However, once a bat goes into hibernation….. BAM! That’s when the fungus attacks! What occurs next is where things start to fall apart.

Bat wing infected by Pd under ultraviolet light, taken by the US Geological Survey

Plain and simple, a bat hibernates to get through the winter. First of all, its prey, i.e. insects, aren’t around during the winter. Also, even if it had prey to eat, a bat is much too small and requires too much energy — flying uses an enormous amount of energy — to survive the cold winters of North America. So what happens?

The federally threatened northern long-eared bat (Myotis septentrionalis), taken by author

The bat wakes up prematurely.. An individual has spent the better part of the fall eating its heart out to store fat (energy) for hibernation. When the bat wakes up, it starts using up those precious fat reserves, e.g. flying around during the daytime in winter, and eventually leads to death. Sadly, this is the usual story and the problem has only worsened over the past 15 years.

The federally endangered Ozark big-eared bat (Corynorhinus townsendii ingens), taken by author

But as always, there’s hope. Bat biologists are actively working to help combat the effects of this deadly disease. In 2011, the US Fish and Wildlife Service implemented a national plan to combat WNS. Epidemiologists (people who study disease), mycologists (people who study fungi), veterinarians, and communicators at all levels are using their expertise to contribute to this cause. Bats are amazing creatures. They eat many agricultural and forest pests that threaten the health of our forests and the integrity of agriculture. Many may not know, but bats are pollinators. For fans of tequila, bats pollinate agave. Next time you take a shot of tequila, pour one out for a bat.

The current image of bats is antiquated. Vampires, horror movies, a mainstay of Halloween, all associate bats with fear. Hell.. Even my favorite superhero, Batman, uses bats as a symbol of fear to take down criminals and his nemeses. There is no need to fear them. Just like any other animal, they want as much to do with you as you do with them. They’re just another animal trying to survive on this rock hurtling through space. So as I’ve said before, don’t go actively seeking out bats. But if you’re lucky enough to encounter one in the dead of the night, admire it from afar and realize you are likely the sole person witnessing this miraculous creature exist.

For more details on what is being done and what you can do to help, head over to www.whitenosesyndrome.org.

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Michael Barnes
Age of Awareness

Wildlife biologist that has an insatiable curiosity for the natural world.