March 28, 2019 03:18 PM
The number of bats in Minnesota has declined substantially, the Minnesota Department of Natural Resources said Thursday, which could impact some insect populations, including mosquitos and moths. However, the decline was expected.
The DNR said the decline is due to the effects of white-nose syndrome (WNS), a disease that is harmful and usually fatal to hibernating bats.
Recently completed bat surveys recorded declines up to 94 percent in affected locations across the state, compared to counts prior to March 2015 when the disease was first confirmed in Minnesota, the DNR said. A 90 percent decrease was observed at Soudan Underground Mine in northeastern Minnesota, along with a 94 percent decline at Mystery Cave in southeastern Minnesota.
"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. Four of Minnesota's bat species hibernate and four species migrate.
The DNR says white-nose syndrome is named for the white fungal growth observed on infected bats, and it's not known to pose a threat to humans, pets, livestock or other wildlife.
While the disease is primarily transmitted from bat to bat, people can also inadvertently carry fungal spores to other caves. The department says some tours have started brief lessons on how to prevent the spread of WNS, and the DNR will continue to urge cave owners to take similar precautions, while also following recommended national decontamination protocols.
Part of the problem with the decline in that bat population is the larger population of the insects bats feed on.
The DNR says it has heard from residents who are starting to notice a dramatic increase in mosquitoes since WNS was confirmed. Along with mosquitoes and other biting insects, bats also eat large numbers of moths. Some moths can damage farm crops and vegetable gardens, and bat losses to WNS could lead to increases in pesticide use.
According to the DNR, WNS was first documented in North America in 2007 in eastern New York and has since spread to 33 states and seven Canadian provinces, killing more than six million bats.
Updated: March 28, 2019 03:18 PM
Created: March 28, 2019 11:04 AM
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