Michigan Bats, Michigan’s Flying Mammals
Early in the 1800’s metallic mineral exploration in Michigan’s upper peninsula there resulted in the creation of thousands of vertical and horizontal mines and pits. These Michigan sites, after mining operations ceased, became depositories for trash, hazardous places open to curious explorers and shelters for Michigan bats and other cave dwellers. Michigan Mines offered optimum bat winter roosting sites (called hibernaculum) due to their relatively constant temperatures, around 54 degrees, high humidity and low Michigan air movement.
One example of the importance of these old Michigan mines is the Millie Hill site in Iron Mountain, Michigan. Conservation practices were deemed necessary after a survey into the abandoned Michigan mine by Marquette fireman and part time spelunker Steve Smith discovered a population estimated at one million Michigan little brown and big brown bats. The mine was heavily vandalized and slated to be closed, threatening the unique Michigan resource.
A Michigan partnership developed between the Natural Heritage Program, the local community, Bat Conservation International and other Michigan state and federal agencies to develop a management plan, including a cage designed to keep humans from entering the shaft while allowing the continued use of the site by bats. Michigan educational programs were conducted to stress the importance of bats in the environment.
Thanks to the concern and involvement of all the Michigan individuals and organizations, the initial phase of the Michigan plan seems to have worked. Michigan Bats in the Millie Hill mine are protected and have free movement in and out of this abandoned iron mine through the “bat cage”.
This Michigan mine has been designated as having significant natural resource features and is now a Michigan Watchable Wildlife viewing area. Improvements are being developed to allow safe public visitation to the site.
Michigan bats comprise one-fourth of the world’s 4,000 bat species of mammals and are most often found in forested areas near water, which are insect-rich areas. Michigan fruit-eating bats are nature’s most important seed-dispersing animals. Michigan nectar bats pollinate many rain-forest trees, shrubs, and flowers and without their help the Michigan forest would be less diverse. The ability of Michigan insect-eating bats is phenomenal–one little Michigan brown bat can eat 600 to 1,000 mosquitoes in an hour. Over-sized ears and nostrils help Michigan bats to use a sonar system that experts believe is a thousand times more sophisticated than the best airport radar invented to date.