11 May 2011

N.S. brown bats endangered by fungus

CBC News

There are fears that a deadly disease killing off brown bat populations in the eastern United States is now spreading in Nova Scotia.

White nose syndrome has been confirmed in one dead bat in Nova Scotia, but six others are being studied at the Atlantic Veterinary College because scientists believe they have the fungus.

The disease was first confirmed in bats in New Brunswick and in Nova Scotia in March.

"Where most of them have been retrieved is in Hants County, which is the epicentre of hibernating areas," Mark Elderkin, a species at risk biologist with Nova Scotia's Department of Natural Resources, said Wednesday.

"But we've found them in outlying areas in Annapolis County and just today outside Wolfville."

Conservationists and scientists in Nova Scotia are watching the situation develop with dread, fearing they are witnessing the outbreak of a mass die-off.

"There is no disease that I am aware of that has had such mass, continental range-wide collapse causally from a single factor. There's a range collapse going with this. There's a numerical collapse of bats that's unprecedented," Elderkin said.

"At best, perhaps we are going to be documentarians of a horrific event."

Scott McBurney, a wildlife pathologist at the Canadian Cooperative Wildlife Health Centre in Charlottetown, says the bat population could collapse. In the United States, it is estimated that white nose syndrome has killed off one million bats.

"It's causing population collapse in hibernacula and local extinction is predicted for some species," Scott McBurney, a wildlife pathologist at the Canadian Cooperative Wildlife Health Centre in Charlottetown, said.

McBurney performed necropsies on two bats this week from Nova Scotia. He found lesions that indicate white nose syndrome. Results from molecular testing are expected within a week to 10 days.

The fungus poses no health risk to humans, but the economic consequences of a large bat mortality could be costly.

"Bats are major insect eaters. Our forestry industry depends on bats eating some of those insects. Our agricultural industry relies on bats eating insects to protect it," McBurney said.

"As humans, bats eat a lot mosquitoes. Mosquitoes are nasty because they bite us but they also carry certain viral diseases."

In Nova Scotia, the public is being asked to stay out of caves and mines to prevent the risk of spreading the disease and to report bats flying in daylight or any other abnormal behaviour.

Metal grates are being mounted to keep people out of bat caves. The hope is to keep fungus from being dragged around on clothing and gear.

Since March, scientists surveyed 14 sites in Nova Scotia where bats are known to spend the winter.

None of the hibernating bats showed signs of the fungus. The fact that six bats have been found dead with suspected infection leads Mark Elderkin to predict a crisis next year.

He fears the fungus will make its way into hibernating site with disastrous consequences.