Northern B.C. caves may be last chance for Canada’s bats: biologists and cavers join forces
By NorthEast News
DAWSON CREEK – Local bat biologists have joined forces with cavers (individuals who explore and study caves) in a program that they hope will help halt a fungus that could potentially kill off half of B.C.’s bat population.
The lethal White Nose Syndrome (WNS)—a disease which has been decimating bat populations in North America since its introduction in 2006—is spreading westward and experts estimate that it could reach B.C. in five-to-ten years.
WNS manifests as a fungus which grows on the nose of hibernating bats, and so far has caused a 99 per cent mortality rate in Eastern North American bat roosts.
The little brown bat (myotis) and northern myotis make up around half of the estimated 16 bat species in B.C., and both have already been listed nationally as endangered, as a result of WNS.
Cori Lausen, Conservation Scientist with the Wildlife Conservation Society (WCS) who initiated this program, says the effects of WNS on B.C.’s bats could be wide ranging, not only for bat populations but to B.C.’s agricultural economy.
Bats consume up to 100 per cent of their body weight in insects each night; a recent study in the U.S. found that projected bat losses due to WNS could result in up to $53-billion in future agriculture loss.
Lausen says a main concern in Western Canada would be an increase in moths, a major pest to forests, gardens and agriculture.
“Moths are mostly nighttime insects, and bats are the main animal that feeds on nighttime insects,” Lausen told Northeast News.
“It’s the moths that we could see increasing in population numbers as the bats go down. What impact is this going to have on our forest? Probably large.”
Lausen went on to explain that only one study has been conducted in B.C. regarding bats and pests, which focused on the spruce budworm moth.
It was discovered that bats play a “significant” role in controlling the spruce budworm, said Lausen.
“Now you can imagine how many different moths there are out there, how many potential forest and crop and garden pests, and none of them have been studied. So we can only assume at this point that we would start to see some heavy ramifications for both the ecosystem and the economy as well. … not only is there going to be a lot of crop lost, but there’s going to be a lot more alternative methods, probably chemical applications that reduce the pest instead.”
This potential circumstance has some proponents of the organic foods industry concerned as well, Lausen says.
The BatCaver program, funded in part by the BC Hydro BC Fish and Wildlife Compensation Program, is aiming to take a preventative measure against WNS.
Using monitoring devices which will be installed by cavers, Lausen’s team hopes to establish strongholds against the disease through discovering habitats which will be WNS resistant due to their temperature and humidity levels.
Cavers will install and deploy ultrasound equipment throughout cave systems and known hibernacula (bat hibernation roosts) throughout Alberta and B.C., which will identify where and which species are overwintering, helping biologists and program managers decide where to focus limited funds and strategy.
“We’re partnering with the people who know these caves, and who are in the best position to help biologists create and implement critical bat conservation strategies,” said Lausen.
As part of a larger bat-tracking program in the Williston Reservoir area, local wildlife biologists Inge-Jean Hansen and Brian Paterson, along with two of B.C.s premier cavers, installed two of the ultrasound “Roostloggers” in Bocock Provincial Park this September.
White Hole cave and White Dwarf cave, both of which had not been entered by humans for thirty years, are prime candidates for bat hibernation.
“Bats need somewhere to go deep into, either a crevice or a cave during winter, to get a constant temperature and humidity so they can hibernate,” Hansen said.
The devices will measure winter temperatures and humidity of the caves; valuable information as the WNS fungus thrives only in almost 100 per cent humidity and relatively moderate temperatures.
“That will give us a really good idea of whether the white nose syndrome is going to impact the bats that hibernate there,” said Lausen.
A hibernacula recently found in Northern Canada that has an average temperature of 2 degrees fahrenheit year-round, gives western biologists hope.
“What that says to a lot of us in the west is that if we can find a large number of bats roosting in these really cold caves, these caves might take on an even higher level of importance, because the fungus is likely not going to grow well there,” Lausen said.
“Therefore those bats that use those caves will likely have a higher survival rate from the fungus, and therefore act as a little bit of a refugium where we know that some of our bats are going to survive and potentially repopulate in the rest of the areas where they’ve died out.”
The British Columbia Speleological Federation and the Alberta Speleological Society are on board with the project, and currently cavers in both provinces have begun deploying the 50 monitoring devices so far purchased for the initiative.
“The caving communities in Alberta and B.C. have been overwhelmingly supportive of helping with bat conservation,” said Lausen in a press release.
“The BatCaver program was piloted last year and the response has already been tremendous. Not only are cavers helping us locate bat hibernacula, but they are developing policies to ensure visiting cavers and members of their clubs do not inadvertently spread the disease westward.”
The BatCaver program has also been funded by Environment Canada, Eden Conservation Trust, BC Habitat Conservation Trust Foundation, Golder Associates, and TD Friends of the Environment Foundation.
Photo Credit: Gray bat (Nessie Grace via Flickr)