19 December 2015

Bat count on hold while population battles white nose syndrome

The once-common little brown bat species has been devastated

CBC News

A bat count in southern New Brunswick won't take place this winter, because researchers say the population has been so annihilated by white nose syndrome, it's best to leave the few survivors alone.

"At this stage, we've got less than half of one percent of what we started with," said zoologist Don McAlpine, who has been counting bats since 2009 at 10 hibernation sites.

McAlpine said he'll make trips once every three years — instead of the biannual visits that allow him to calculate mortality over the winter.

In the laboratory, the focus turns to cataloging the carcasses. Thousands of mummified bat bodies, collected over the years, are stored in freezers in the basement of the New Brunswick Museum.

Richard Blacquiere, Andrew Sullivan, and Gayathri Sreedharan spend their days meticulously measuring, slicing and sampling tissue and recording findings about the genetic material.

Another researcher, Karen Vanderwolf, has left Saint John for the University of Wisconsin. That state is the new frontier, as the disease that was first recorded in New York, continues to move westward.

McAlpine said the decline in bats has been quite dramatic and very rapid.

That rings true to Jim Wilson, a naturalist and birder. A bat house hangs under his roof in Quispamsis but the pair of bats that used to roost there, hasn't been seen in some time.

"Year after year there would be bats in the bathouse," said Wilson. "Within the last two or three years, none, absolutely none."

"There isn't a flickering of bats against the sky at sundown. There isn't bats flying around street lights at night. And suddenly, you miss it."

McAlpine says the remaining cave-dwelling bats have probably all been exposed to white nose fungus and while there are some survivors, it's unknown if they have a natural resistance.

The white nose fungus grows around the mouths and wings of bats. It causes them to come out of hibernation early, leading them to die of starvation and exposure.

The once-common little brown bat species has been devastated. The northern long-eared bat has also been completely wiped out in some North American regions.

It's believed that white nose fungus was accidentally transported to North America from Europe. European bats have a natural immunity.