MILES CITY – A myotis bat, found dead in Fallon County in southeastern Montana, has been confirmed positive for white-nose syndrome.
The bat was sent to the U.S. Geological Survey National Wildlife Health Center in Madison, Wisc., for analysis. It tested positive for Pseudogymnoascus destructans (Pd), the fungus that causes white-nose syndrome (WNS) in bats. A pathologist also confirmed characteristic WNS lesions in the skin of the bat.
Biologists with Fish, Wildlife & Parks have been closely monitoring for WNS in recent years as part of an effort to track the impacts of the disease once it arrives, but this is the first case detected in Montana. Bat droppings and environmental samples collected in six eastern Montana counties last summer tested positive for the Pd fungus; however, presence of the fungus does not necessarily confirm the presence of the disease. Also last year, WNS was detected just across the border in North Dakota.
WNS has killed millions of bats in North America since 2006. A powdery white fungus grows on the skin of hibernating bats, often on the face ̶ hence the name “white nose.” The fungus causes irritation and dehydration, causing bats to arouse early from hibernation and to exhaust fat stores they need to survive the winter.
WNS has now been confirmed in 36 states and seven Canadian provinces. It can wipe out entire colonies of bats and has caused dramatic population declines in eastern states. WNS is not known to affect humans, pets, livestock or other wildlife.
“Bats provide important services in protecting crops and timber from flying insect pests,” said Kristina Smucker, nongame wildlife bureau chief for Montana FWP. “Bats also eat tons of mosquitoes each year, meaning they play a role in reducing the spread of some mosquito-borne diseases. Like we do for all wildlife, we are doing what we can to keep bat populations healthy.”
In 2020, FWP temporarily prohibited the capture of all live bats due to unknown risks of COVID-19-infected humans inadvertently transferring the virus to bats. While some sampling of live bats has resumed in 2021, particularly to survey for Pd and WNS, biologists are taking recommended precautions to minimize any risk of COVID-19 spillover to bats. In many places, to substitute for sampling of live bats, biologists have been collecting bat droppings or environmental swabs at roosts to sample for Pd and to look for any bat mortalities that might be attributable to WNS. They visit known roost areas, including the undersides of bridges.
State and federal agencies are asking for help to monitor the spread of this disease. Anyone seeing a dead or sick bat, or group of bats, should not handle them, but rather call a local FWP office for further guidance.
“Like other wildlife, bats may get sick or die for a variety of reasons,” said Emily Almberg, disease ecologist for Montana FWP. “We are particularly interested in investigating clusters of dead bats or bats that are found dead during the winter or early spring.”