Three of the Keweenaw’s bat species migrate south for the winter, with some, like the hoary bat, traveling as far as Central America before returning to their spring and summertime breeding grounds in North America.

The remaining four species spend their winters hibernating deep within caves and abandoned mine shafts throughout the region. Approximately 90% of Michigan’s hibernating bats overwinter in the Upper Peninsula, with these hibernation sites — called hibernacula — housing anywhere from a few individuals to tens of thousands.

While their erratic flight patterns and nocturnal behavior cause some people to fear them, bats play a vital role in Michigan’s ecosystem and economy.

A single bat can consume thousands of insects in one night, including disease-carrying mosquitoes and crop-damaging pests.

By naturally controlling insect populations, bats reduce the need for pesticides, with some studies estimating they save U.S. farmers more than $3 billion per year.

But Michigan’s ecologically and economically important bat populations are facing serious challenges, including habitat loss and becoming infected with white-nose syndrome.

Entire colonies can be lost within a few years because the fungus spreads from cave to cave and from bat to bat through social grooming and close contact.

In response to the rapid decline of Michigan’s bat population, the Keweenaw Bay Indian Community organized a collaborative research effort known as the Bat Blitz in 2024.

Made possible through federal funding from the Bureau of Indian Affairs and the U.S. Fish and Wildlife Service, the goal of the Bat Blitz was simple: to build skills for bat conservation entities by training together and sharing expertise across state, federal and tribal agencies.

Over the course of three nights, biologists from the Keweenaw Bay Indian Community’s Natural Resource Department were joined by partners from the Sault Ste. Marie Tribe of Chippewa Indians, the Little Traverse Bay Bands of Odawa Indians, the Pokagon Band of Potawatomi, the Michigan Department of Natural Resources and the U.S. Fish and Wildlife Service.

The biologists closely monitored the nets throughout the night, and once captured, the bats were carefully removed, examined and documented before being released unharmed.

Because Michigan is home to over 500 vertebrate wildlife species, this type of cross-agency training is crucial.

While it is common for environmental agencies in Michigan to have someone on staff who specializes in wildlife, it is rare to have someone with extensive experience with bats. And with experts estimating that 52% of bat species in North America are at risk of severe population declines in the next 15 years, time is important.

“It’s always great when you get together with an open mind and share techniques and knowledge,” said DNR biologist and 2025 Bat Blitz attendee John DePue, who specializes in bats. “While all our biologists are experienced with wildlife, some are just starting in the bat world and don’t have a lot of hands-on experience. Those of us who do are happy to teach. We’re passionate about bats, and we enjoy sharing our tools and techniques with others.”

Joining DePue at the Blitz was Kyle Seppanen, a wildlife researcher with the KBIC’s Natural Resource Department, who helped host the event.

Three bat species were captured during the most recent Bat Blitz, including a little brown bat that was fitted with a small tracking transmitter before release.

These tiny radio transmitters are temporarily attached using a safe adhesive, allowing researchers to track the bats’ movements. Scientists use antennas like the Motus Wildlife Tracking System to detect the signals for short periods of time, as the transmitters are designed to fall off after a few weeks. This data helps researchers better understand habitat threats and identify migration and roosting areas.

The data collected through the Blitz will also support field-based training for dog detection teams and advance efforts to locate and protect bat roosts on lands managed by the Little Traverse Bay Bands of Odawa Indians in Emmet County.

A bat roost is any place a bat uses for shelter and protection from predators. Common roosting sites include caves, hollow trees and human-made structures such as attics or mines.

Bats often have multiple habitats for hibernation and breeding. Protecting maternity roosts is especially critical for the survival of Michigan’s bat populations, and knowing their location helps conservation efforts.

“Even though bats are sometimes referred to as ‘mice with wings,’ they are very different from mice,” said Jenny Wong of the U.S. Fish and Wildlife Service, who also attended the Bat Blitz. “Rodents can produce dozens of litters a year, resulting in hundreds of offspring. Most of Michigan’s bat species give birth to just one pup annually. Even though some species can live 30 to 40 years, their low reproductive rate means every individual matters when it comes to rebuilding populations.”

You can also assist the DNR and the Michigan Natural Features Inventory at Michigan State University by reporting bat roosts through the Roost Survey Form on the MNFI website.

“The public’s perspective on bats has changed,” Seppanen said. “People want to help bats now instead of immediately wanting to kill them because they understand how important bats are to our ecosystem and economy.”

Working with bats is not without risks, and handling them is not recommended due to the risk of rabies. Only about 1-5% of bats carry the disease, which is a significantly lower rate than raccoons, which test positive at roughly 20%.

To combat the risk of disease, the biologists involved with the Bat Blitz emphasize handling every bat with care during their collaborative training sessions.

“We wear personal protective equipment to protect ourselves while handling bats,” DePue said. “But we handle every bat like it’s the last of its kind on the planet.”

Another cross-agency Bat Blitz is scheduled for later this year.

“I’m hoping we can expand tribal participation and further strengthen these partnerships this year,” Wong said. “These efforts help us identify where surviving bat populations remain and focus conservation efforts where they are needed most.”

Learn more about Michigan’s bats and bat conservation at Michigan.gov/Bats.