Devastating disease threatens bat population in province

Karen Vanderwolf & Don McAlpine; Telegraph-Journal Archive

New Brunswick could lose its entire bat population in a few short years, researchers say, because of the devastating white nose syndrome that is ravaging caves from Nova Scotia to Oklahoma.

The fungus, whose scientific name is almost self-explanatory (geomyces destructans), was first detected by researchers in a cave in Albert County on March 15.

At that point about a quarter of the bats in the cave were dead, said Karen Vanderwolf, a University of New Brunswick graduate student. The cave floor was littered with dead bats and the air “smelled of death and rotting carcasses,” she said.

Dressed in HazMat suits, she and her research supervisor Don McAlpine, the zoology curator at the New Brunswick Museum, returned to the cave in late April. In little over a month, mortality had jumped to almost 90 per cent.

“And that’s a minimum,” Vanderwolf said, “A lot of the bats on the wall that we counted as alive were probably dead.” Half of them already had visible signs of the fungus.

The fact that Vanderwolf and McAlpine were able to go back at all is unusual. Many jurisdictions are prohibiting any human entry to the caves, to help prevent the disease from spreading.

“It’s a good thing we went back in because otherwise we wouldn’t have realized how serious a problem it is,” said Graham

Telegraph-Journal archive

Forbes, who is co-supervising the research. Forbes is a professor at the University of New Brunswick.

On June 29, the United States Fish and Wildlife Service announced that it may add two bat species to its endangered species list because of white nose syndrome. One of those species – the northern long-eared bat – is one of New Brunswick’s most common bats.

Forbes, who also serves as a co-chairman for the committee on the status of endangered wildlife in Canada, said there has been preliminary discussion of whether Canada should follow suit.

Luckily, the disease doesn’t seem to have spread to other parts of the province, Vanderwolf said. But she expects that will have changed by next winter.

Forbes said New Brunswick is on the verge of losing a species that has traditionally been one of the province’s most plentiful creatures. And if that is the case, he said it could be up to 50 or 60 years before the population recovered. This is because bats are the slowest reproducing mammal in the world for their size, often bearing only a single baby per year.

If bats were wiped out, there is the possibility that its main food sources – mosquitos and moths – would multiply to irritating and dangerous levels. Crops could suffer from higher populations of harmful bugs, Forbes said.

The fungus works by seeping into the skin, irritating the tiny creatures into wakefulness during their hibernation period. More time awake means using more energy, and the bats’ fat stores soon run dry. Vanderwolf said researchers so far know the disease to attack nine different bat species, including the common small brown bat.

Vanderwolf said there is no chance white nose syndrome could spread to people because the fungus favours colder host habitats that fall below the human body temperature.

Previously published July 5, 2011; Telegraph-Journal