Much-feared Halloween favourites, it's bats that are facing danger
Published Wednesday, October 30, 2013 10:47AM ADT
A taphozous perforatus bat is shown in a handout photo, released on Wednesday August 21, 2013. (THE CANADIAN PRESS / HO, EcoHealth Alliance - Jonathan H. Epstein)
VANCOUVER -- They are the stuff of Halloween horror stories, the alter-ego of vampires, the frightful beasts that foreshadow the macabre.
Bats strike fear in many hearts, but it is these nocturnal mammals that are in danger, decimated by a mysterious disease that has wiped out seven million in North America in a few short years.
"Wherever it shows up, it has a significant impact," said Graham Forbes, a biologist at the University of New Brunswick and a member of the Committee on the Status of Endangered Wildlife in Canada subcommittee. "Some caves are basically becoming empty."
In February 2012, COSEWIC held an emergency assessment for the tri-colored bat , the Little Brown Myotis and Northern Myotis and found all three were endangered by white-nose syndrome, so named because of the white fungus that grows over the faces of infected bats.
A recommendation was made to the federal environment minister that an emergency order be issued listed them as endangered under the federal Species at Risk Act. In November, a COSEWIC committee will meet again to discuss their status and vote on another recommendation.
The outcome is unlikely to surprise.
"It's bad and it got worse," Forbes said.
By the end of last winter, the disease had been confirmed in 22 U.S, states and in Ontario, Quebec, New Brunswick, PEI and Nova Scotia. In New Brunswick, it is estimated about 99 per cent of the known winter population of little brown myotis, or little brown bat, has died.
The disease has not yet been confirmed west of Ontario, but it has been found in Minnesota, south of Manitoba, and it's spread about 200 to 400 kilometres per year since it first appeared in New York state in February 2006. It is believed that as many as seven million bats have died since.
The fungus grows in cold weather, and it hits while bats are most vulnerable, hibernating in caves and old mines through the winter. Experts believe the fungus was introduced in North America by a visitor from Europe, where it has existed for some time and where bats have developed resistance.
"The population here just has no immunity to it," Forbes said. "They haven't been exposed to it before."
Some provinces have closed off access to caves and other known hibernation sites to limit the spread, but biologists may be in a race against time.
"We basically feel like we're in this race and we don't know how long we have to get to the finish line," said Cori Lausen, the bat biologist for the Wildlife Conservation Society of Canada.
Lausen, with a grant from the Sustainable Forestry Initiative, is working with the Nature Conservancy Canada to secure bat habitats in British Columbia, tapping into the province's caving community to find hibernation sites, or hibernacula, and count the bats that take shelter this winter.
The shadow of white-nose syndrome has cast bats in a new light, and biologists have realized how little they know about the small mammals in western Canada.
"We don't have these big hibernacula like they do in the East, so we don't even know what to monitor quite frankly. White nose could already be here and we wouldn't necessarily know," Lausen said.
"So far we have no reason to believe it's here."
Although white-nose syndrome has not been found in B.C., the westernmost province is home to 16 of the 18 bat species in Canada and half of them are already considered at-risk.
One looming threat is the growing presence of wind farms -- a threat that wasn't realized until the first turbine went up in northeastern B.C. and killed two Eastern red bats, a species biologists weren't even aware existed in the province.
"It was a real red flag for us that we don't know enough about our bats and we better figure it out fast," Lausen said, adding that one recent study estimated that as many bats have died in North America from wind turbines as have died from the syndrome.
"Here we have been very concerned about white-nose because it's killing millions and millions of bats, and this wind energy has been doing the same thing but we haven't ever pooled all the data together enough to realize it."
The threats have prompted an image makeover for bats, which eat up about 1,200 mosquito-sized insects an hour each. Cavers have been keen to help with bat counts, and bat houses are increasingly popular with the public.
"Suddenly they're not just a pest," she said.