It’s almost Halloween. Pumpkins abound and spooky decorations are showing up everywhere. As a bat biologist, I find bats amazing rather than spooky, and I enjoy the bat-themed décor this time of year. But as you may have heard, all is not well in the world of bats.
Bat populations in eastern North America are experiencing up to 95% declines due to a new disease called white nose syndrome (WNS). First described in 2006, the disease gets its name from the fuzzy white growth seen on the noses of infected, hibernating bats. The fuzz turns out to be a fungus that was most likely introduced from Europe, possibly by cavers. It’s brand-new scientific name is Pseudogymnoascus destructans, but everyone refers to it as Pd.
Pd grows on cold surfaces – like the body of a hibernating bat at less than 10°C. It causes sores on the nose, ears and wings, resulting in dehydration. Infected bats wake often from hibernation to find water. This burns precious stores of fat, causing many bats to starve to death before the spring. WNS has killed millions of hibernating bats since it was first discovered – the fastest decline ever documented in wild mammal populations.
Declines of 95% are a tragedy in any species, and in bats they might also have economic impacts. But the beautiful mystery in this story is the survival of the “final five percent” – the bats that survive at sites where 95% have died. Bats in Europe, where the fungus is native, don’t seem to die from infection. What if they have a genetic resistance to white nose syndrome? Could similar resistance also exist in some North American bats?
Dying bats… potential extinctions… Depressed yet? Here’s the good news: the response to this crisis involved an almost unprecedented amount of cooperation, ingenuity and hard work. Since 2006, scientists, government agencies and citizens in the U.S. and Canada have been working hard to look for solutions. Some are testing potential biocontrol methods for white nose syndrome, while others are monitoring bat populations or monitoring the spread of the disease.
I am using my Liber Ero Fellowship to study how bats respond to infection with Pd – specifically, what genes respond, and whether some North American bats might show resistance to the fungus. Using samples collected by researchers across Canada, I am also identifying geographic barriers to gene flow in Canadian bats. Barriers to gene flow represent areas that a species doesn’t cross. These may be obvious barriers like mountain ranges, or less obvious barriers like areas with little suitable food. Because the fungus is spread partly by bats themselves, we can use this information to predict how the disease will spread as it continues to move west across Canada.
In future posts, I’ll update you on my work and on other efforts to save our bats, and tell you how you can help. In the meantime – Happy Halloween!