State wildlife officials are concerned a large bat die-off in Keweenaw County this month might be a sign of things to come.
The small brown bats died from white-nose syndrome. The distinctive white nose is created by a fungal growth that typically kills most of the bats hibernating in an infected cave.
“We should be prepared for anywhere between 50% and 90% mortality in all of these infected hibernacula,” says Dan O’Brien, a wildlife veterinarian with the Michigan Department of Natural Resources. A hibernacula is a place where animals hibernate. “We’ll not only see deaths at those sites, but also newly infected sites and probably die-offs at newly infected sites.”
Since the disease was first discovered in New York state in 2006, roughly 6 million bat deaths have been attributed to white-nose syndrome.
Discovered just last year in five Michigan counties (Alpena, Dickinson, Keweenaw, Mackinac and Ontonagon), O’Brien expects white-nose syndrome may infect most, if not all, Michigan bat colonies by 2016.
Conservative estimates place Michigan’s bat population in the hundreds of thousands. The estimate is based on the number of bats that live in caves, mines and other large hibernacula. The number does not include the many bats that call home attics, bell towers and other structures home.
Michigan is home to many species of bats. The small brown bat which more common in the northern part of the state is especially susceptible to white-nose syndrome.
Wildlife officials are concerned a large scale die off of bats could have effects on Michigan’s ecology.
Bats subsist on insects. If the bat population is substantially decreased, there is concern that could allow crop-damaging insects to grow in number and pose problems for Michigan agriculture.
While state wildlife officials want to encourage people to report bats with suspected cases of white-nose syndrome, they stress people should not try to touch possibly infected bats.
“We understand the public will be concerned, and we share their concern for the plight of these bats,” said DNR wildlife veterinarian Dan O’Brien. “Unfortunately, there is nothing that the public can do to help the bats that are now dying.”
O’Brien says bats remain a potential carrier of rabies, and for that reason, it is best not to come into contact with them.