Defenders of Wildlife Blog

Big brown bats shelter under the eaves of a house (©Jim Conrad)

Nina Fascione, Vice President of Development

I was watching TV with my family last Saturday evening at our house on Maryland’s Eastern Shore when we heard a scratching noise in the wood stove. Another bat had come down the chimney and was stuck in the stove pipe. My husband Steve put on gloves and fetched it out. It was a big brown bat – Eptesicus fuscus – one of the larger of the Maryland bat species. It was beautiful. And pissed off, refusing to hold still for a decent photo. We released it outside and went back to the (bad) movie we were watching.

The fact that we regularly find bats in our second home doesn’t bother us. Steve and I are both wildlife professionals and fully appreciate the myriad ecological benefits that bats provide. Anyone who has spent time on Maryland’s Eastern Shore has experienced aggravating swarms of mosquitoes and other disagreeable pests that insectivorous bats help to control with their voracious appetites. And bats aren’t just helping us out with the annoying bugs (although I’m delighted that they eat stinkbugs). Bats help control insect pests that cause billions of dollars in agricultural damage in North America each year. From pecan growers in the southeastern U.S., who have bats to thank for their consumption of the damaging pecan nut casebearer, to the Texas cotton farmers whose crops are safer because millions of Mexican free-tailed bats love to dine on corn earworm moths, bats provide tremendous ecological services. A study in the journal Science estimated that the value of bats to the U.S. agriculture industry ranges from $3.7 billion to $53 billion per year. For these services, we are happy to share our home with these visitors from time to time.

What does worry us is that although this most recent visitor was a big brown bat, we are not finding little brown bats in our house, as we did several years ago. We are concerned that this might be due to white-nose syndrome, the devastating bat disease that is ravaging populations of hibernating bats in as many as 22 states and five Canadian provinces. Populations of the little brown bat – Myotis lucifigus – have crashed in recent years; by more than 90% in some states and known hibernation caves.

Little brown bat with white-nose syndrome
(Photo courtesy Ryan von Linden/New York Department of Environmental Conservation)

White-nose syndrome is named for the fungus Geomyces destructans, which looks like a white power on the bat’s nose, ears and other body parts. Ten North American bat species have been infected with the fungus to date, and more are potentially vulnerable. The disease has killed upwards of 5.7 million insectivorous bats, and so far scientists have not found a cure. Most frightening is that losses are so severe that researchers are predicting regional extinctions of the little brown bat – previously one of America’s most common mammals – in northeastern states within 15 years.

For the past few years, Defenders has been engaged with a coalition of groups working to secure federal funds for white-nose syndrome research and management. Our coalition successfully obtained four million dollars in the 2012 fiscal year budget to go toward research into treatments, surveying caves and educating the public about this problem. Now we are working to stop budget cuts to wildlife funding that would impact bats and other wildlife. While all wildlife programs are important, and those that deal with imperiled species particularly need to be fully funded, bats are in an especially dangerous position and we can’t afford not to do everything we can to help them. We will continue to raise the issue of white-nose syndrome on Capitol Hill so that our elected leaders understand the need to halt this disease. One hopeful note is that white-nose syndrome is a non-partisan issue. I have met with congressional leaders of both parties who understand the impacts of white-nose syndrome and want to help (I even had two Republican congressional offices ask me how to put up bat houses!).

Staff from the U.S. Fish and Wildlife Service survey bat caves to find where the disease has spread. In this cave in Missouri, the bats are healthy. (©Ann Froschauer/USFWS)

Everyone can take steps to help bats. First and foremost is to stay out of caves and mines where bats are known or suspected to roost. This is especially important during winter months when bats are hibernating. Bats have limited fat reserves to keep them alive during the long winter – and bug-free – months. Once aroused, their metabolism speeds up and they burn vital calories. One of the main causes of death from white-nose syndrome is starvation, as the fungus wakes bats and they have no food available. Human disturbance only adds to this lethal problem.

Another way to help is by spreading the word about the importance of bats and the threat of white-nose syndrome. Urge your federal representative and Senators to support adequate funding for endangered species recovery efforts. This would benefit the listed Indiana bat and gray bat, both of which have been heavily impacted by the white-nose syndrome fungus, as well as other critically imperiled wildlife species.

And Steve and I will continue to provide a home for bats in our attic. Let’s hope we see some little browns this summer.

Bats with white nose syndrome

The Fish and Wildlife Service (FWS) announced today that white-nose syndrome (WNS) has been confirmed among gray bat populations found in Tennessee.  Already listed as endangered, this announcement comes as a blow to the gray bat as their populations have started to make a comeback nationwide.  Although no deaths among the gray bat populations have been attributed to WNS, they were not one of the previous 6 bat species that had been diagnosed with the disease.

For more information on WNS, read Defenders’ magazine article here.

Over the years, bats have gained a fearsome reputation due to their nocturnal behaviors and Dracula’s fame. But if you actually take a closer look, you’ll find that instead of looking scary, bats are actually quite cute! More important, they are vital members of the natural world because they pollinate plants and eat pest insects that damage crops.

Bats with white nose syndrome

What’s really scary is that many of those insect-eating bats in the Northeast are dying in large numbers from a mysterious disease called white nose syndrome (WNS), which is a fungal infection that affects hibernating bats in cave ecosystems. The fungus responsible for WNS is new to science and is named Geomyces destructens. A fuzzy white growth on the bats’ muzzles gives the disease its name, but the fungal growth has also been found on their ears, tails and the tender tissue of their wings. Scientists believe that bats are waking up more often during winter, perhaps as a result of the disease, and are dying because they use up all their already depleted fat reserves.

Now what are the economic impacts of these bat die-offs? An average of one million bats, the number of estimated WNS fatalities to date, consume around 700 tons of insects, most of which are crop pests. So in the absence of these natural pest controllers, farmers will have to spend a lot more to manage the pest insects that affect their crops.

Six species of bats have been affected by the disease, and little brown bats have taken the brunt of it. If the disease rages on at current levels, they will soon lose their status as the most abundant bat species in the U.S.

WNS first drew public attention in 2006 when wildlife officials and cavers began to see hundreds of dead bats littering the floors of caves. Since then, it has spread so rapidly that it is now present in states all the way from Vermont to Missouri and Oklahoma – as of now, it has been documented in 13 states. Six species of bats have been affected by the disease, and little brown bats have taken the brunt of it. If the disease rages on at current levels, they will soon lose their status as the most abundant bat species in the U.S.  Endangered species like Indiana and gray bats are also highly vulnerable to this disease, and since they hibernate in a few select colonies, it wouldn’t take much at all to drive these two species to extinction.

While scientists continue to discover new information about the disease every day, there are still many unknowns. Extensive research is needed to answer these questions, and in turn, funding is necessary to carry out this research. You can help by writing to your Congress members and asking them to increase federal funding for WNS research. Find out more about this deadly disease in the latest issue of Defenders magazine.