The Minnesota Department of Natural Resources reported on Thursday, March 28, the continued bat decline, saying it was expected, but not welcome.
Despite years of research and tracking, no cure has been found against the European fungus that has spread from a single cave in New York in 2007 to 33 states and seven Canadian provinces kill more than 6 million bats as far as spread west. Fishermen's officials have called the most catastrophic wildlife disease in American history.
In Minnesota, the decline has been as rapid as it has been broad. The fungus that causes white nose syndrome was first discovered at the Soudan mine in 201
Bats spread out in hectic months in the summer when they consume huge amounts of insects. Four of Minnesota's eight bats migrate south in the winter, but the four other tiny bats, northern long-eared bats, three-colored bats, and large brown bats are grouped in colder months in warmer areas such as caves and underground mines. This composition makes perfect breeding grounds for the deadly sponge to spread.
"Although there may be a rare hibernaculum in Minnesota that has not yet been affected, there will likely be white nose syndrome anywhere bats hibernate in state," said Ed Quinn, DNR's natural resource program manager.
The news has been just as bad in Wisconsin, where wildlife workers last year reported a 92 percent drop in bats from historical figures and white nose syndrome confirmed in 25 of the 28 counties that have bat winter areas, called hibernacula.
White nose syndrome is named after the white fungal growth observed on infected bats. It is believed to come from Europe, where it is common, but where most bats do not die from it. It is not known to pose a threat to humans, pets, pets or other wildlife. Although the disease is transmitted primarily from bats to bats, people can unintentionally carry sponges on clothes and cave equipment.
Bats that develop the fungus start to waste. Infected bats show unusual behavior, such as. To fly during the day in summer or leave caves during their usual winter sleep when there is no fault for them to eat. A wild veterinarian at the University of Wisconsin confirmed that the disease kills bats by causing their organs to overheat, burning energy too quickly and at a time – in the winter – when there are no insects present to replace the lost calories, and is too cold for the mammals to survive outside.
The DNR mammal Gerda Nordquist said that they already hear from Minnesota residents who see few if any bats have also been a major increase in mosquitoes and mills. A single bat can eat more than 1,000 mosquitoes in a single night.
There has been some hope in recent years with the success of using UV light and fungicides to kill the fungus. Other researchers hope that some bats can develop resistance to the disease with enough survivors to rebuild the population. It seems to have occurred in small numbers in some eastern American bats colonies that have hung at low levels.
Bats can live for 30 years, but reproduce slowly, generally with a puppy a year, so if there is a cure, it will take decades to rebuild the population if even possible.
Bats are considered important for ecosystems because they eat so many insects, and some species pollinate fruit and flowers. A Minnesota bat influenced by white nose syndrome, the northern long eared bat, was given federal threatened species law protection in 2015.
To learn more about white nose syndrome and Minnesota's bats, or to submit a report, if you find a dead bat and suspected white nose syndrome, go to mndnr.gov/wns.