Biologists crawling through a dark cave in northern Canada recently made a troubling discovery: a small bat covered in a spindly white fungus. The deadly disease known as white-nose syndrome has reached the northernmost bat caves in North America, but researchers hope a new probiotic treatment could give vulnerable bat populations a fighting chance.
White-nose syndrome is caused by a dangerous fungus called Pseudogymnoascus destructans. Over the past 20 years, the disease has spread across North America, killing more than 6.7 million bats. The fungus grows on the wings and faces of bats while they hibernate during cold winter months. Infected bats wake up too often to groom themselves, quickly burning through the fat reserves they need to survive until spring. As a result, many bats die from starvation or dehydration.
Ecologist Jesika Reimer and biologist Joanna Wilson discovered the infected bats near Fort Smith in Canada's Northwest Territories, about 450 miles south of the Arctic Circle. The 11-chambered limestone cave shelters around 3,000 bats, making it the largest winter home for bats in western Canada. Scientists had hoped they would have more time to study the healthy population before the fungus arrived, but tests confirmed the infection is already present.
Small species face the greatest danger from the disease. In caves where the fungus has spread, it killed up to 90% of little brown bats and 99% of northern long-eared bats. The northern long-eared bat weighs only six to nine grams. Because these tiny creatures have very small fat reserves, experts fear they could completely disappear from northern ecosystems if the fungus spreads unchecked.
To stop the destruction, scientists are turning to a promising new solution: probiotics. Researchers are developing a probiotic spray made from natural, healthy bacteria found on bat wings. Applying this probiotic cocktail could help bats build stronger natural defenses and resist the fungal infection during winter hibernation, giving threatened species hope for survival.