Killer fungus: how a disease threatening bat species has spread to northern Canada

Bat experts were shocked at how fast white-nose syndrome had reached Canada’s northernmost colonies from the US. Now, the race is on to find a cure before species disappear Crawling through a narrow passage in a cave beneath a boreal forest near Fort Smith in Canada’s Northwest Territories in May, two biologists spotted a lifeless bat on a limestone ledge, its body covered in a spindly white fungus. When they shone their headlamps to get a closer look, they saw another bat with the fungus on its forearms. “It hissed at us and crawled back into a crack,” Jesika Reimer says. For Reimer, an ecologist specialising in bat populations in northern Canada and Alaska, there was little doubt. For 20 years, white-nose syndrome, a lethal disease caused by the fungus Pseudogymnoascus destructans (known as Pd), has swept west across North America, spreading from bat to bat and cave to cave, killing more than 6.7 million bats. The fungus attacks their face, wings and arms while they are hibernating. They stir from rest and groom themselves, burning through the fat and energy reserves they need to survive the winter, and eventually die from dehydration or starvation. Smaller bats with lesser fat r