DNR: 'Substantial' decline in MN bat population due to White-nose Syndrome

Image 1 of 2

(Photo: Minnesota DNR)

Minnesota’s bat population continues to decline due to White-nose Syndrome, which is having ripple effects across the ecosystem.

The Minnesota DNR said the declines were “substantial but expected,” thanks to the disease that is usually fatal for hibernating bats.

The DNR reports declines up to 94 percent when compared to the same survey taken in March 2015.

“While there may be a rare hibernaculum in Minnesota that hasn’t yet been impacted, WNS is likely to be present anywhere bats hibernate in the state,” said Ed Quinn, DNR natural resource program supervisor.

The surveys were conducted at the Soudan Underground Mine in northeastern Minnesota and at Mystery Cave in southeastern Minnesota. A 90 percent decrease was reported at the Soudan Mine and a 94 percent decline at Mystery Cave.

The DNR said the bat population decline has led to a “dramatic increase” in mosquitoes and moths. Mosquitoes are a common nuisance to humans and can carry disease, while moths are a threat to farm crops and gardens.

The DNR suggests that the bat decrease could therefore increase pesticide use among farmers and gardeners.

White-nose syndrome is not a direct threat to humans, pets, livestock or other wildlife, but it can be carried from cave-to-cave by humans.

For that reason, tours of caves include safety sessions that provide lessons to visitors about avoiding spreading the disease. Guests are instructed to not wear the same clothes when they visit other caves.