Bats tend to get a bad rap, but there is ongoing work to educate people on learning to live with bats, especially as a deadly disease continues to wipe out populations across North America.
Greg Horne, who has worked for Parks Canada since 1977, said white-nose syndrome (WNS), a deadly fungal disease, has killed off an estimated 5.7 million bats since it first arrived in North America almost 10 years ago.
“It’s been described as one of the biggest wildlife disasters of the 21st century, rivaling most in the 20th century,” said Horne during a presentation hosted by the Bow Valley Naturalists on Oct. 22.
“These bats are going to become more and more precious and more endangered because of white-nose syndrome. In some hibernacula there’s a 90 to 95 per cent mortality. It’s that dramatic.”
WNS was first discovered by a photographer in a cave in New York State in 2006. The deadly disease hit Eastern Canada in the winter of 2009-2010.
A white fuzzy fungal growth is seen around the nose and on the wings of infected bats. The disease interrupts hibernation and they quickly use up fat reserves that get them through winter.
Infected bats often emerge earlier from hibernation than they should and are seen flying around midwinter. These bats usually dehydrate or starve to death.
“The exact cause of death is unclear, but it’s probably starvation and damage to the wing. All combined, it can do them in,” said Horne.
“The same fungus is found in healthy bats in Europe. For some reason, they have an immunity that bats here don’t have.”
Horne said bats that have survived when others haven’t in the hibernacula are being closely watched.
“There is a lot of interest in those survivors,” he said. “They could be the ones that genetically have the genes that the European bats do.”
In Canada, the disease has been confirmed in Ontario, Quebec, New Brunswick and Nova Scotia and is said to be spreading at a rate of between 200- and 400 kilometres per year.
Movement of bats between Manitoba and Ontario has been documented in historic banding records, so scientists expect it’s only a matter of time before WNS appears in Manitoba.
British Columbia is said to have the most to lose of any province in Canada, given it is home to 16 species of bats, the greatest bat diversity in the country.
Experts can’t say for sure if and when the disease will hit Alberta.
“The worst case scenario is it could be in northern Montana in 2016, but others have said western North America by 2022,” said Horne. “It could be faster, it could be slower.”
As a precautionary measure in Canada, three species of bat last year underwent an emergency assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).
The little brown bat, tri-coloured bat and northern myotis were assessed by COSEWIC as endangered and recommended for protection under the Species At Risk Act (SARA). This has not yet happened.
Banff National Park most certainly has one of those bat species, the little brown bat, and possibly the northern myotis. Other bats found in Banff are not designated endangered, but are vulnerable to the disease.
Parks Canada is planning to inventory its bats before the potential arrival of WNS, while in Jasper they are already investigating caves and mines for signs of bat use.
Horne said cave climate data is being collected, noting this fungus is basically neutralized around 20 C, but thrives in low temperatures of about 5-14 C and high levels of humidity.
“A lot of caves can be two degrees, so maybe it’s a hair too cold so that could save us,” he said.
Wind turbines are proving to be deadly to bats, too, particularly for migrating species such as the hoary bat and silver-haired bat, in summer and into the fall.
Horne said most bat deaths appear to be caused by barotrauma, severe lung damage due to sudden drop in air pressure from the rotating blades. The speed at the blade tips may exceed 320 kms per hour.
“They’re not killed by the blades themselves,” said Horne.
During his presentation, Horne spoke not only of the threats facing bats, but also talked about the potential threat of rabies when bats bite people.
The most common way for rabies to spread is by biting. At least four species in Alberta have tested positively for rabies - little brown myotis, big brown bat, silver-haired bat, and hoary bat.
Horne said there were incidents involving bats biting or landing on people in Jasper National Park this year, which had people heading to the health unit for rabies shots.
In one case, a bat bit a woman as she slept in her hotel room in Jasper, while in another instance a bat bit a camper at the Whistlers Campground.
A bat also landed on a woman’s back as she hiked the Valley of the Five Lakes.
“I’d be nervous if that happened in the middle of the day. It might be rabies,” said Horne.
“If bats are doing strange things in the day and biting you out of the middle of nowhere, take it seriously. It’s not idle fear mongering. It’s a real concern.”
Neighbouring Banff has not experienced similar incidents.
There have been only two reported occurrences in the last two years, one of a distressed bat trapped in a room at The Banff Centre in July and the other report of bats in an attic in September 2012.
In 2011, a bat that bit a woman at a picnic area at Bubbling Springs near Jasper made CBC National news. “The bat flew over and bit her,” said Horne.
Nine bat species live in Alberta, including big brown bat, eastern red bat, hoary bat, little brown myotis, long-eared myotis, long-legged myotis, northern myotis, silver-haired bat and western small-footed bat.
People typically only encounter two of the species frequently -– the big brown and little brown myotis, with the remaining species residing as solitary individuals where people seldom see them.
Banff is home to seven of the nine bat species in Alberta.
There are no known hibernacula in Banff National Park, but there are four known bat hibernacula in Alberta, including Wapiabi (Chungo) Cave, southwest of Nordegg, Cadomin Cave, south of Hinton, Procrastination Pot east of Jasper and Walkin Cave, south of Fort Smith.
Recent developments in electronic bat acoustic monitoring equipment now allow passive recording of bat activity entering and exiting of caves, mines or buildings.
Given the size of Banff National Park, its rugged terrain and its relatively low human use away from highways, Horne said the potential for many more, yet to be discovered, caves is huge.
In a recent paper, he said the fact that none of the known caves are hibernacula for bats is simply random chance based upon historic and current human use patterns in the park.
“The potential for Banff National Park to presently have one or more important hibernacula is very reasonable,” he said.
“Because bats can access very restricted places, even the known caves in Banff cannot be completely dismissed as not having hibernaculum use in portions of the caves inaccessible to humans.”
If people encounter bats, they are asked to call Parks Canada.
Horne said it’s best not to kick them out or handle them.
“If you can live with them, all the better because pretty soon you will have bragging rights – ‘I’ve got 50 to 60 bats’,” he said. “The best thing we can do is to try to live with them and try to appreciate them.”
