Creature Control

A Sad Day for Michigan’s Bats

For years, wildlife specialists and the Michigan DNR have been attentively watching Michigan’s bat population for signs of the deadly White Nosed Syndrome, known as WNS. WNS is a fungal disease that has decimated bat populations in New York and other states. The disease is spread from state to state as the brown bats migrate throughout the seasons. Because cases of WNS have been found among the Indiana brown bat, which hibernates in Michigan, researchers were on end throughout 2010 and 2011 expecting outbreaks of WNS in Michigan. This never materialized and Michigan’s bats have been safe from WNS for the past few years.

Unfortunately, routine DNR checks in northern Michigan this spring have definitively identified the presence of WNS in five of Michigan’s brown bats. While it is disappointing, it is not surprising. WNS has been located in Indiana, but also in Wisconsin and Illinois. Given that the bat populations of the surrounding states all are carriers, it was only a matter of time until the fungal disease came to Michigan. White-nose syndrome is mainly spread from bat to bat, but it is also possible for humans to transport spores via clothing and gear from fungus contaminated sites such as caves and mines.

Named for the white fuzz that appears on the nose, wings and tail, the disease frequently causes hibernating bats to wake from the inert state, according to the Wisconsin officials. That depletes their stored energy reserves and can cause them to starve or become dehydrated before spring arrives.

It is uncertain how WNS will affect Michigan’s bats. In certain caves in Wisconsin, as much as 95% of bats in an infected colony have died. Since 2006 WNS has infected 11 different bat species and killed almost 6 million bats in 23 states.

So what’s the big deal? While many folks do not like bats, the fact is they are tremendously helpful to Michigan’s ecosystem. They eat thousands of tons of mosquitoes and other insects every summer. If the bat population of Michigan succumbs to WNS, there will be a corresponding rise in the number of insects this summer. This in turn will have two negative consequences: (1) Michigan crops will suffer more damage from insect-pests than usual, and (2) with more mosquitoes around, there is a greater liklihood that cases of West Nile Virus will increase this year.

Hopefully, Michigan’s bats will weather the storm better than those of New York and Wisconsin; there is really no way to stop the spread of WNS since it is the migratory actions of the bats themselves that spread it. It serves as another reminder that ecosystems are delicate and each creature, no matter how small or physically unappealing, has a very important role to play.