More than a dozen volunteers trudge down a hill one Friday night just outside Billings with only headlamps to light their way.
They’re here mothing, or using light to catch and observe moths for fun and sometimes research, as is true here.
In the lead is Marian Kirst, a Billings-based insect photographer and entomologist who works for the nonprofit Northern Rockies Research & Educational Services.
“It’s a really nice sort of lush habitat in here,” Kirst says on the trek down.
The group is at the popular Four Dances Recreation Area just outside Billings, near where the train tracks and busy interstate cross the Yellowstone River.
Look one way and the horizon picks up light from the city; look another way and fluorescent spots mark an industrial sprawl. But on the ground, walking through the brush, it’s dark and a little colder than a typical August night in South Central Montana.
Nestled in this ravine are several traps Kirst and her group set up earlier in the night. Kirst stops at one and crouches down to see what moths are fluttering around it.
“Who’s this little guy?” she says. “Look at the face on this little cutie.”
Research suggests moths use natural light to orient themselves. The traps are mounted with lightbulbs.
“What’s actually happening is it’s not that they’re attracted to this light. It’s that the light is sort of confusing them,” Kirst says.
Planes of plexiglass fixed on top of the trap knock the moths down into a chamber.
There, poison kills them so that in the morning, Kirst and her citizen scientists can sort, freeze and mail the specimens to Colorado for collection.
This is part of the first comprehensive effort to document what moths are in Montana and where.
Northern Rockies Research & Educational Services kicked off the Moth Project in 2020 as a collaboration between Montana biologist Mat Seidensticker and Chuck Harp at Colorado State University’s C. P. Gillette Museum of Arthropod Diversity.
Harp says this project is part of an effort to catalog insects across the Rocky Mountain West and southwestern U.S.
Harp says insects are great indicators for researchers who study climate change because they’re the first animals to leave when the temperature changes.
“You don't know what you lose if you don't know what was there in the first place,” Harp said.
For every hour volunteers spend capturing moths, Harp and his students spend many more hours pinning them and digitizing their information.
“Each week, I’m getting new things that have never been collected in the state before, and that's exciting, to see what is possible here,” Harp said.
According to the Xerces Society for Invertebrate Conservation, there are 11,000 identified species of moths in North America.
Mat Seidensticker with Northern Rockies Research & Educational Services says the C. P. Gillette Museum of Arthropod Diversity now houses the single largest collection of Montana moths.
“It's really that distributional data that becomes highly important when we're talking about land management and conservation and things like that in the end,” Harp said.
Back in Billings, Bureau of Land Management Biologist Rebecca Newton is spending her Friday night mothing with the others here on BLM land. Newton says this is valuable data for land managers to use when they analyze impacts to public lands. She also says mothing is fun.
“The more you look, the more you see, the more curious you become,” Newton said. “And it just opens up this whole world of exploration. It renews that curiosity in the natural world in a really fulfilling way.”
The next morning, some of the volunteers join Marian Kirst at a picnic table to sort the moths they collected the previous night. They use tweezers to move the moths into piles on a metal pan.
From here, they’ll pack the moths up in disposable food containers, freeze them and send them to the museum in Colorado.
Kirst says volunteers and staff have sampled each county at least once as of August, and Northern Rockies Research & Educational Services over the next few years will go back to sample at different times in the year and different locations in each county.
Kirst says Northern Rockies Research & Educational Services has already discovered new moth species with the help of citizen scientists.
Ideally, Kirst says, the group will be able to send mothing kits to volunteers in Montana’s rural communities to help do the data collection themselves.
“Basically giving people the tools and the confidence to be natural historians in their own right,” Kirst said. “Because that personal sense of discovery, there’s nothing else like that.”
