MONTREAL – In March, Frédérick Lelièvre found himself crawling through a narrow passage into the final chamber of the Laflèche Cave in Val des Monts. Raising his eyes to the hibernating bats on the rock above him, his heart dropped. The tiny lime-size animals were dusted with a white powdery substance. Most of them had it on their muzzles, and it was on the wings and the feet of others. It wasn’t a good sign.
Wildlife biologists in the United States have come across similar sights over the last four years. Since 2006, a strange new fungus has been spreading through bat roosts, from New Hampshire to Oklahoma, leaving a grisly mess of rotting bat carcasses and toothpick-size bones in its wake.
Until recently, the fungus had remained south of the border. But by March, the illness – dubbed white-nose syndrome – had spread to Ontario as well as Quebec.
Despite the scene before him, Lelièvre clung to the faint hope that this was something different. Unlike the bat hibernacula in the U.S., the Laflèche Cave wasn’t littered with carcasses.
“We looked at many, many bats, and we found the mould on them, but we found only a few dead bats,” says Lelièvre, a biologist at the Quebec Department of Natural Resources and Wildlife.
Lelièvre sent whole bats to the Centre québécois sur la santé des animaux sauvages at the Université de Montréal faculty of veterinary medicine in St. Hyacinthe for necropsies to look more closely at the bats’ condition. Skin samples taken during the necropsy were then sent to the National Wildlife Health Centre in Madison, Wis., where a genetic test was used to identify the fungus. Both studies are necessary for diagnosis.
André Dallaire, a veterinary pathologist, studied the animals – outside and in – for signs of the infection. The fungus looks like “what you’d see if you had a piece of bread that you left too long on the countertop,” he says. Some of the bats he examined were emaciated, having burned though their body fat and muscle to try to stay alive.
By mid-April, Lelièvre had received word that the bats from the Outaouais area cave carried the same fungus as those in the U.S.
“I was very worried. I thought, ‘Oh, no! Are we also going to lose our bat populations?’ ” says Lelièvre.
More than one million bats have died in the U.S. In some hibernacula, 90 to 100 per cent of the bats have been reduced to a pile of bones. Aeolus Cave in East Dorset, Vt., – the largest hibernaculum in New England – once held an estimated 300,000 bats, says Scott Darling, a wildlife biologist with the Vermont Fish and Wildlife Department. Now about one-tenth of the initial population remains.
The loss of so many bats has ramifications for humans and the ecosystem. Bats are ravenous predators of night-flying insects, moths, beetles and mosquitoes, some of which transmit human diseases and others that may damage crops and trees.
Some have likened their vanishing to bee colony collapse disorder.
“We’ve put a dollar value on what bees do for conservation, but I don’t know anyone who can put a dollar value on bats,” says Brock Fenton, a bat biologist at the University of Western Ontario, in London.