Bats and Mines in Michigan
A little brown bat.
Michigan's Copper Country is known worldwide for the tremendous copper production of the past 150 years. Along with this comes literally thousands of miles of abandoned workings that now provide one of the most important bat hibernation habitats in the midwest. Every year millions of bats return here in late fall to find safe and optimal hibernation conditions.
The Adventure Mine provides habitat for primarily two species of bats, the North American Little Brown Bat and the North American Big Brown Bat. During the summer, the bats range throughout Michigan and several surrounding states with very few remaining at the mine location. In late September they begin to return to find suitable hibernation locations with most bats returning to the same place year after year.
The Adventure Mine is actively working in cooperation with Bat Conservation International (BCI) to protect our bats and help stop the spread of white nose syndrome. Click here to learn more about BCI and White Nose Syndrome.
Winter brings many any bats into the mine. They cluster together to help keep warm.
- Little Brown Bats, which are only about 2 inches in length, are the world's longest lived mammal for their size. Many live to be over 30 years old.
- A single Little Brown Bat can eat over 1,200 mosquitoes in a single hour.
- Bats are exceptionally vulnerable to extinction. Producing only one off-spring annually, they are the slowest reproducing mammal for their size.
- All mammals can contact rabies. Less than one-half of one percent of bats may contain rabies. No more than any other mammal. *Little Brown Bats cannot bite through human skin. Their teeth are not large enough since they are intended for small insects.
- Over half of American bats are endangered.
White Nose Syndrome
White nose syndrome was discovered in February 2006 in New York. In just a few years, it has killed more than a million bats in 14 states. The mortality rate is nearly 100%. More information is available from BCI here.
The cause is still not understood, but what is known is the disease is spreading quickly and there is a concern that it is spread by humans moving from one mine or cave to another.
We are currently taking precautions to help prevent the spread of White Nose Syndrome. We are asking anyone visiting the mine that has been exposed to bats in the last year and a half to: 1) not wear the same clothing or boots/shoes in the mine; 2) wipe off any camera equipment, bags, water bottles, etc to help us keep this disease out of the mine.
Our custom in-house designed and built bat friendly gates help to let bats in but keep vandals out. After a previous incident of persons breaking and entering to steal mineral specimens, building bon fires underground, and damaging a tour route; this has become a high priority project. We wish to thank the National Resource Conservation Service and BCI for their help in funding these critical bat habitat friendly gates.
We can also do custom design and fabrication work for other locations. If you are looking for a high security and bat friendly mine closure please contact us. Click here for more information on our services available.
Gate over the "Ice Cave" allows bats to fly in and out while keeping the opening secure.
Bat Population Inventories
We have been working with Dr. Allen Kurta of Eastern Michigan University and Steve Smith of Iron Mountain to provide accurate counts of hibernating bats, assessments of bat species found in the Adventure Mine, and banding of select bats for future studies.
The small metal band is put on the wing of the bat.