We may not be able to hear or see them, but bats are all around us. During the summer, they take to the sky at night, flying through Maine neighborhoods and forests, across lakes and fields, snatching up insects. During the winter, they gather in caves to hibernate or migrate south to warmer climates.
Maine is home to eight bat species, and most of them are in big trouble.
Concerned about recent declines in bat populations, Erik Blomberg, assistant professor of the University of Maine Department of Wildlife, Fisheries and Conservation Biology, recently created BatME, a bat monitoring project that relies on volunteer “citizen scientists” to collect data throughout the state.
“I usually study birds,” Blomberg said. “But with recent concerns about bats, I recognized there’s a need for people to do research on bats in Maine.”
The biggest threat to bats in the United States today is a disease called white-nose syndrome. First detected in the country in 2006, in a cave in New York, the disease has spread rapidly, killing an estimated 5 million to 7 million bats throughout the U.S.
In January, Blomberg attended the annual Northeast Bat Working Group meeting in South Portland. There he learned about Wildlife Acoustics, a Massachusetts-based company that has developed a mobile device that detects bat calls, which are at such high frequencies that they can’t be heard by humans.
“I thought, ‘Boy, this would be a great tool to get citizen scientists involved,’” Blomberg said. “It gives them a way to interact [with bats].”
Blomberg has seen people from the public interact with birds for years, but bats have always been a different story.
“Unlike songbirds, bats are drably colored, only active at night and we can’t hear them sing,” Blomberg said. “Usually the only time people interact with bats is when they’re in a house. Then it’s not a positive experience.
“Bats historically have had a stigma of being bloodsucking vampires and scary. They don’t have the greatest reputation,” Blomberg said. “At the same time, they’re important for people. They deal with harmful pests, like mosquitoes and crop-eating insects.”
Blomberg proposed the idea of a citizen-science bat monitoring project to officials at the Maine Department of Inland Fisheries and Wildlife, which worked with him to secure a grant through the Maine Outdoor Heritage Fund to support a pilot project. He also teamed up with Maine Audubon, an organization that works to conserve the state’s wildlife habitat through education and conservation.
The pilot project took place July through September.
Twenty volunteers were issued BatME detector kits. With these kits, they collected more than 4,000 detections of bats throughout the state.
Logan Parker of Augusta was among the volunteers.
“I was going out every night and detecting a lot of bats,” said Parker, who monitored for bats for three weeks, starting in late July. “I started out really local. I’m from Augusta, so I went into the backyard of my childhood home because I was curious about what was back there.”
In his search for bats, Parker traveled throughout central Maine, visiting public walking trails, lakeshores and wetlands of Rome, Baldwin, Manchester, Belgrade, Unity, China and Smithfield. He also took a trip to western Maine, to Milton and Redding, and sometimes brought along family and friends, as well as a group of home-schoolers.
The list to sign out the bat detectors filled up quickly at Audubon centers. They had to turn some people away because the pilot project was limited to five BatME kits, Blomberg said.
Parker, the community engagement coordinator for the Maine Lakes Resource Center, has been interested in bat conservation for several years and has even given public lectures on bats. But that wasn’t always the case.
“It started with me not really knowing anything about bats and being afraid of them, actually,” he said. “But when I heard about white-nose syndrome a few years back, it encouraged me to start learning about them and reassessing what I thought about them. I found out I had all these misconceptions.”
Each kit consists of a Wildlife Acoustics EchoMeter Touch Microphone, an Apple iPad Mini2, an extension cable for the microphone, a charger cable and a protective case. The kits cost about $900 each.
To navigate, bats use echolocation, emitting high-frequency sounds that echo off surfaces to relay information back to them about their environment.
The iPads in the BatME kits are equipped with an app that converts these high-frequency bat calls into lower frequencies humans can hear, as well as a visual representation, so volunteer monitors know instantly when a bat is nearby.
Furthermore, the application instantly identifies the bat species based on its call. Different species of bats have evolved different call frequencies suited for their preferred habitat.
With his BatME kit, Parker detected six of Maine’s eight bat species.
“It’s amazing,” Parker said. “There was one pond I went to specifically that was really cool near Woodstock, Maine. We stationed ourselves there just after sunset, and the detector was completely silent for a while. Then, all the sudden was just this boom of activity, and you could actually see the bats silhouetted against the sky.”
During the pilot project, volunteers recorded a total of 1,645 detections of big brown bats; 535 detections of eastern red bats; 581 detections of hoary bat; 1,427 detections of silver-haired bat; 139 detections of little brown bats; 74 detections of tri-colored bats; and no detections of small-footed bats or northern long-eared bats.
The numbers reflect the drastically declining populations of certain cave-dwelling bats in Maine that have been most affected by white-nose syndrome: small-footed, little brown, northern long-eared and tri-colored.
“Ten years ago, little brown bats would have been the most abundant out there,” Blomberg said. “So that’s disheartening.”
In addition to simply walking around with the detector, some volunteers did driving transects, fastening the EchoMeter Touch Microphone to a yard stick and holding it out a vehicle window while driving a certain route at a speed of about 20 mph, detecting bats along the way.
“Presumably that’s faster than a bat will fly,” Blomberg explained. “So that will give us the relative abundance of bats in an area.”
Blomberg used this method of detection while driving the gravel roads of Sunkhaze National Wildlife Refuge in Orono, and he detected 76 bats in one drive-thru.
“It’s nice to see,” he said. “Most of the news is doom and gloom, but data shows they’re still out there.”
The pilot project of 2015 demonstrated to Blomberg that the mobile bat detector is effective and allows citizen-science volunteers to collect high-quality data with minimal training. He plans to purchase additional detector units and ramp up the volunteer involvement next year, creating a statewide, long-term monitoring project.
BatME plans to announce opportunities to participate in the project through Friends of Dr. Edith Marion Path, the Orono Bog Boardwalk and the Maine Audubon.
For information about bat conservation efforts underway across the country, visit batcon.org.