YELLOWSTONE NATIONAL PARK — Halloween has come and gone, but bats in Yellowstone National Park (YNP) are facing something scary.
YNP announced that while park biologists conducted bat population research this summer, they encountered the fungus Pseudogymnoascus destructans (referred to as “Pd”) on 28 little brown bats from two colonies in the northern area of the park. This is the first time the fungus has been found in the park since bat population monitoring began in 2019. The fungus was also detected in Glacier National Park this year.
The fungus causes white-nose syndrome, a disease that has killed millions of bats in North America by damaging bats’ skin and disrupting hibernation. Afflicted bats wake more frequently during hibernation, which depletes the fat reserves they need to survive winter, per the park. Bats with the disease develop white muzzles and wings, and might demonstrate unusual behaviors like flying outside during the day in freezing temperatures. The disease spreads via physical contact between bats; it can also linger on surfaces in bat hibernation sites.
“Although the fungus does not harm humans, people can spread Pd from their clothing or gear after visiting affected caves,” YNP’s announcement states. “Park visitors can help Yellowstone bat populations by reporting any odd bat behavior to a park ranger and avoiding direct contact with bats since they can also carry diseases like rabies. Though rarely seen, bats play an important role in ecosystems by controlling insect populations, pollinating plants, and dispersing seeds.”
The syndrome has been spreading across North America since first being detected in upstate New York in 2006, per the National Park Service. It is present in most U.S. states and Canadian provinces by now. The illness has been responsible for declines as high as 99% in wintering bat populations, leading to regional extinctions of several species in northeastern North America. Bats cannot recover quickly, if at all, from these substantial population declines because most species that are vulnerable to the syndrome rear only a single pup per female each year.
Yellowstone has 13 species of bats living within the park: little brown bats, big brown bats, long-eared myotis, long-legged myotis, Townsend’s big-eared bats, fringe-tailed bats, hoary bats, silver-haired bats, spotted bats, pallid bats, California myotis, Western small-footed myotis and Yuma myotis. Approximately 1,400 bat species exist worldwide, accounting for around 20% of all mammal species on earth, according to the nonprofit that runs Bat Week. This makes bats the second-largest group of mammals, behind rodents.
Bats were a hot topic of discussion in Jackson last year, when a colony was found to be living inside Jackson Lake Lodge in Grand Teton National Park.
