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Townsend’s big-eared bat. Photo by Ann Froschauer/USFWS.

Townsend’s big-eared bat. Photo by Ann Froschauer/USFWS.

White-nose syndrome now confirmed in six
Minnesota counties; fungus detected in Texas

White-nose syndrome, a disease that has killed millions of hibernating bats, has now been confirmed in six Minnesota counties, according to the state’s Department of Natural Resources. The disease was confirmed in Becker, Dakota, Fillmore, Goodhue and Washington counties. Minnesota’s first confirmed case of WNS was in St. Louis County in March 2016.

Recent bat surveys conducted by the Department of Natural Resources found declines in the annual bat count ranging from 31 to 73 percent in locations where WNS has been confirmed. The 73 percent decrease was observed at Soudan Underground Mine in St. Louis County, where the disease was first confirmed in Minnesota a year ago. Department of Natural Resources biologists think the sharp decline there may reflect how long the disease has been present.

“While some locations are still testing negative, the results of recent surveys lead us to conclude that WNS is likely to be present anywhere bats hibernate in Minnesota,” said Ed Quinn, Department of Natural Resources Program Supervisor. “Four of Minnesota’s bat species hibernate, and four species migrate. WNS will have a substantial effect on Minnesota’s hibernating bat population.”

Public tours will continue at Soudan Underground Mine and Mystery Cave, where the Department of Natural Resources will continue to follow recommended national decontamination protocols to prevent human transport of fungal spores. The Department of Natural Resources urges owners of private caves to learn about WNS and take similar visitor precautions as outlined in the protocols.

In January, researchers in Texas found the state’s first occurrence of the fungus that causes white-nose. The fungus was detected in six north Texas counties in three species of bats, including the tri-colored bat, cave myotis and Townsend’s big-eared bat. This is the first detection of the fungus on both cave myotis and Townsend’s big-eared bats. The Townsend’s big-eared bat has an isolated subspecies in the East; the Virginia big-eared bat has already tested positive for the fungus.

“This discovery is significant because it occurs where the ranges of eastern, southern, and western bat species intersect, and two of these bats have extensive distributions in Central America and the West – beyond the current range of the disease,” said Jeremy Coleman, National White-nose Syndrome Coordinator for the U.S. Fish and Wildlife Service, who leads a coalition of more than 100 state, federal, and international governments agencies, academics, and non-governmental organization working to defeat white-nose syndrome. “While we don’t know how new species of western hibernating bats will respond to the fungus, we are concerned about this move into the West.”

White-nose syndrome is caused by the fungus Pseudogymnoascus destructans (Pd) and is responsible for the deaths of millions bats in the United States and Canada. It has been expanding in all directions since its discovery in New York in 2007. In some states, there have been declines in winter bat numbers of greater than 90 percent.

“There is still hope for bats in Texas,” said Jonah Evans, Texas Parks and Wildlife Department State Mammologist. “The fungus thrives in colder climates and it remains to be seen if WNS will have the same serious impacts in Texas as it has in northern states. Additionally, 20 of the 32 species of bats in Texas do not regularly hibernate and we are hopeful they will not suffer significant population declines. We will continue working with cooperating landowners and researchers to implement the best management tools available to conserve these species.”

The announcement that the fungus causing white-nose syndrome has been found in Texas brings the total number of states with the fungus to 33. Of those states, 30 have been confirmed with white-nose syndrome.

From Minnesota Department of Natural Resources and Texas Fish and Game news releases.

A little brown bat with white-nose syndrome. Photo by Marvin Moriarty/USFWS.

A little brown bat with white-nose syndrome. Photo by Marvin Moriarty/USFWS.


Last updated: June 8, 2020