wnsbat

An infected little brown bat. Photo © USFWS Headquarters

Biology, Research

Fatal Fungus Wiping Out Bat Populations on East Coast

Scientists scramble to save bats as White Nose Syndrome spreads across North America.
BY Ellen Jakubowski on

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Out for a late winter walk in 2006, I was suprised to see a bat flying around in broad daylight in a wooded area of Bedford, Nova Scotia. Seven years later, Nova Scotia’s bat population is hanging by a thread and I have to wonder whether White Nose Syndrome (WNS), at that time just becoming known, was behind the strange behaviour I witnessed.

Out for a late winter walk in 2006, I was suprised to see a bat flying around in broad daylight in a wooded area of Bedford, Nova Scotia. Seven years later, Nova Scotia’s bat population is hanging by a thread and I have to wonder whether White Nose Syndrome (WNS), at that time just becoming known, was behind the strange behaviour I witnessed.

Since its discovery in New York State, WNS has spread rapidly throughout Northeastern North America and taken the lives of roughly 6 million bats. Caused by a fungus known as Geomyces destructans, WNS leads bats to wake prematurely from hibernation and seek food, only to deplete their fat stores and die from starvation, dehydration or hypothermia. Symptoms include white fungal growth on the nose and other parts of the body, as well as weight loss and erratic behaviour like daytime flying. The disease has been observed in 11 species so far.

WNS has decimated bat populations in Eastern Canada and the Northeastern US, with cases confirmed in five provinces and 22 states. Over 90 per cent of the bat population has been lost in some places including Nova Scotia and Quebec. The disease has been expanding westward and the fungus responsible has recently been identified in Minnesota and Arkansas, meaning the WNS will likely take hold there within two to three years.

Scientists have estimated that bats save the US agriculture industry $3.7 billion every year due to the volume of insects they consume and presumably their disappearance from North America would have an impact on the economy. More research is needed to elucidate the role bats play as well as to save them from the disease, but this becomes increasingly difficult as the number of subjects dwindles. Ann Froschauer, WNS spokesperson for the US Fish and Wildlife Service, describes the situation as a “race against time…The science is moving very quickly but the disease seems to be moving a little bit quicker.”

Some recent research has identified benign relatives of the infectious fungus. Hopefully comparing them to the infectious strain will shed light on the disease’s pathology. The WNS-causing fungus was also found for the first time on bats in the UK, which appear to be resistant to infection. The next step is to determine what it is about these bats that gives them immunity. There is some hope that a WNS vaccine could be engineered.

However, according to Ms. Froschauer, this would be a big step since most existing vaccines target bacteria and viruses and mammalian bodies react to fungal infections much differently. “If we got to the stage where we had a vaccine then we would have to move on to the challenge of how would we administer it to a small, flying mammal.”

A team of biologists in Glacier National Park, British Columbia is already taking precautions in case WNS reaches that far. Their goal is to determine whether bats there have been exposed to the fungus and to collect data on their activity to help create a plan to protect them.

Researchers across the continent are careful not to carry fungal spores to new locations, donning all-encompassing disposable suits and following strict equipment disinfection protocols. 

Some Canadian scientists are calling for the federal government to take rapid action to protect bats, beginning with listing them as endangered. The province of Nova Scotia recently added the little brown bat, northern long-eared bat and tri-coloured bat to its endangered species list, but they still remain unprotected under federal legislation.

According to Frederick Leighton, executive director of the Canadian Cooperative Wildlife Health Centre, “listing the species as endangered would be a very positive thing … because it would improve the resources Canada could muster to try to do whatever we can… .. We need more money in Canada targeted on research and the monitoring of bat populations in general, to understand the global implications of this fungus on bats, and also on the human economy.”

Biologists are also recruiting the help of citizen scientists to track bats. Nova Scotians can visit batconservation.ca to report their sightings, whether usual or unusual bat behaviour; otherwise, residents of Eastern Canada should contact their province’s natural resources department. Staying out of caves where bats are known to roost is also recommended to prevent disturbing them or spreading the disease.

At a barbecue in Guelph, Ontario, last weekend, my friends and I were delighted when a bat joined the festivities to gobble up the much less welcome mosquitoes. They’re there when we need them… and now, they need us. 

Learn more about bats in the upcoming Night issue of A\J. Get it on newsstands the week of September 17, or subscribe now and you’re guaranteed to get it at home.

Ellen Jakubowski is a former A\J editorial intern with a BSc in Biology from the University of Guelph and a science communication diploma from Laurentian University. She works as an interpreter at the Cambridge Butterfly Conservatory and blogs about animals in The Wild Side.