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Bats are in trouble, but humans are working to help
Bats are in trouble, but humans are working to help
April 20, 2023
People have long had a fascination with bats, whether it tips towards admiration or revulsion.
English writer D.H. Lawrence expresses a bit of both in his 1923 poem, “Bat,” in which swarms of bats come out from cover at darkness in Florence, Italy:
“A twitch, a twitter, an elastic shudder in flight
And serrated wings against the sky,
Like a glove, a black glove thrown up at the light,
And falling back.”
There’s lots of nighttime fluttering and flitting going on across both of Michigan’s peninsulas. Bats known to live in Michigan include the Little Brown Bat, the Northern Long-eared Bat, the Evening Bat, the Hoary Bat, the Big Brown Bat, the Tri-colored Bat, the Indiana Bat, the Silver-haired Bat and the Red Bat.
In Michigan and other Great Lakes states, bats now need more than human fascination. And forget about the revulsion, too. These small, night-flying mammals need our compassion, empathy and assistance to survive, thrive and keep eating the mosquitoes that plague us after sundown.
The Indiana Bat, which lives in some of Michigan’s southernmost spots, is already on the federal endangered species list. The northern long-eared bat was designated as threatened in 2015 and recently reclassified as endangered. If Michigan’s other small forest bats (little brown bat and tricolored bat) continue to decline as expected, they will likely be federally listed.
On top of that, some species of bat in Michigan and across North America are in a steep population decline, dying before their time from a fungal disease that attacks them during hibernation.
White-nose syndrome awakens infected small bats from hibernation too early. By disrupting their winter sleep cycle, the bats rapidly deplete their fat reserves and are unable to survive the winter. Bats with white-nose syndrome also can exhibit unusual behavior such as flying during daylight hours or gathering outside caves in cold weather when they should be hibernating inside.
The Michigan Department of Natural Resources has implemented several bat conservation initiatives and has worked with researchers from universities to try a variety of ways to help bats weather these threats, including:
- Building gates to keep people out of caves and abandoned mines where bats spend the winter. Bats that rely on insects for food need to hibernate undisturbed since they have no winter food supply.
- Participating in field trials of potential treatments to help bats battle white nose syndrome.
- Treating hibernation areas to kill fungal spores when bats are not present.
The DNR is also experimenting with using mining ventilation techniques to reduce the temperature by a few degrees at the Carp Lake Mine, where bats are known to hibernate, to figure out whether it can discourage growth of the fungus.
Recently, Michigan took another step in helping bats by entering into a multi-state plan to modify forest management practices to ensure beleaguered bats have spaces and places in the forest to live and raise their young. While bats may hibernate in caves, they raise their young in trees during the summer.
The Bat Habitat Conservation Plan addresses the potential positive and negative impacts of forest management on bats, and contains biological objectives designed to help bat populations grow again.
“The Lake States Forest Management Bat Habitat Conservation Plan integrates forest practices with conservation actions to help imperiled bat populations in Michigan survive,” said Keith Kintigh, acting supervisor of the planning and adaptation section for the DNR’s wildlife division.
Among other things, the Bat Habitat Conservation Plan is designed to keep tree cutting on participating lands at a minimum near roosting sites while bats are raising their adorable little offspring, known as “pups,” in the summer.
For example, in southern Michigan, where the endangered Indiana bat roosts, there’s no cutting within 2.5 miles of known bat roosting locations in June and July on participating lands. It also establishes statewide no-cut buffer zones around so-called “maternity roost” trees for all bat species and no-cut zones around the entrances to bats’ winter hibernation spots – unless the cutting is to improve bat habitat.
For new road and trail construction on DNR lands, no removal of large-diameter trees is allowed during the June-July pup season.
There is plenty you can do yourself to give bats an edge on survival. Conserve bat habitat on your own property, put up a bat house, don’t go into mines that are closed for hibernating bats and following decontamination guidelines to reduce the spread of white-nose syndrome. Learn more at Michigan.gov/Bats.
Treat bats with respect and leave them alone. If you find a bat outside, don’t touch it or try to catch it. Let it be. In situations where a bat has been in close contact with people, confine the bat if possible and contact your local health department to determine if it should be tested for rabies. Learn more at Michigan.gov/Rabies.
We’ll leave you at sunset in Florence with D.H. Lawrence again, as bats usher in the beginnings of night:
“Look up, and you see things flying
Between the day and the night;
Swallows with spools of dark thread sewing the shadows together.”