While Bay Area native Kristin Tieche was a student at Syracuse University, she sat outside on a summer’s evening at the Inn Complete pub, looking up to see a sky filled with bats. The grad student in film and television realized that there had always been bats all around the area—she had just never noticed them before.
“Flash forward,” the longtime environmentalist said, “to a New Yorker article I read by Elizabeth Kolbert” detailing how bats were dying from white-nose syndrome. “In one upstate New York cave, they had all died. I wondered, ‘Were some of these the bats that I saw?’”
As a filmmaker she wanted to follow the story, and also convey what she found so that more people would understand it. She made a 10-minute short on bats that premiered at Planet in Focus in Toronto in 2016.
“Trump was elected a month later, and I decided to empower myself with Earth knowledge,” she said, “knowing that his administration was going to roll back environmental protections.” She completed a certificate in sustainability at City College of San Francisco in 2018—and embarked on the journey that would lead to the documentary film she’s currently completing, The Invisible Mammal.
According to the U.S. Department of the Interior, there are more than 1,300 known species of bats in the world, and 47 in the United States. In the San Francisco Bay region, 16 species have been documented, according to the Santa Clara County Open Space Authority. Three bat species designated by the state as species of special concern—the western red bat, pallid bats and Townsend’s big-eared bats—pass through San Jose “as occasional foragers or transients, but are not known or expected to breed within city limits,” according to a report prepared for San Jose’s Downtown Strategy 2040 report, and “are more likely to occur in or near less developed areas or open spaces around the periphery of the city (not in Downtown).”
Another short film produced and directed by Tieche, Bats in Russian River Wineries, focused on a bat population living in a winery in Sebastopol in western Sonoma County. Researching this film, she met Corky Quirk, founder of NorCal Bats, and Yolo Basin coordinator at the Yolo Basin Foundation.
“There are 250,000 Mexican free-tailed bats living under the Yolo Causeway,” said Tieche, adding that this is the largest colony of the species in California. Part of the feature-length The Invisible Mammal will document Quirk’s work as she leads “bat walk-and-talks.”
The main storyline will shift to Michigan’s Upper Peninsula, where a group of female scientists, under the aegis of Bat Conservation International, are conducting a project called “Operation Fat Bat.” Tieche explained it’s been demonstrated that one of the reasons the bat death rate from white-nose syndrome is so high is that the fungus itches, causing the bats to wake up during winter hibernation periods. Few insects are available as a food source during the cold hibernation months, so the active bats deplete their fat storage, and starve to death.
The scientists, including UC Santa Cruz’s Dr. Winifred Frick, are capturing and tagging remnant populations of little brown bats, who live in the Upper Peninsula’s abandoned copper mines, and whose numbers have declined precipitously as a result of white-nose syndrome.
“Operation Fat Bat” is experimenting with creating “bug buffets,” large lighted sources that attract insects, and can potentially feed the bats in winter. “The film will examine if they are able to find a solution that can be shared,” Tieche said.
But Tieche’s first stop in her first year of filming was Bracken Cave in Texas. Frick, of Bat Conservation International, had told her about the cinematographer who eventually became the film’s director of photography, Skip Hobbie. Filming bats in their natural habitats, caves and other dark places, is very difficult. “Skip had filmed at Bracken Cave and Congress Avenue Bridge countless times, so I knew he was the right person to help me show viewers how incredible these little flying mammals are,” Tieche wrote in an article on batcon.org.
“When the sun started setting, and the 20-million Mexican free-tailed bats began to emerge, the heat, the sweat, the smell of guano, all dissipated as the spectators and I watched and listened in wonder. We were immersed in a batnado. This was an unparalleled experience in nature that I’ll never forget, one that we hope to convey to viewers on the big screen with surround sound,” Tieche reported.
Bats are not only an “invisible” mammal, she noted, but a much misunderstood and unjustly feared one. An invaluable part of the ecosystem, they are pivotal pest controllers, eating not only mosquitoes, but multiple kinds of crop-destroying insects. Farmers that are lucky enough to have bat colonies nearby rely much less heavily on pesticides, since many species of bats can eat their own bodyweight in insects each night.
“And they are pollinators and seed-dispersers,” said Tieche. “If you like tequila, you should know they are the major pollinator of the agave plant.” They aid in reforesting areas by dropping seed in their guano. Overall, they are key to a “healthy, bio-diverse ecosystem,” she said.
Bats’ remarkable echolocation abilities—they emit bursts of sounds and listen to the echoes that bounce back to detect objects in their environment and to perceive the objects’ location, size and even material—to locate their prey are being studied for possible use by blind humans. “Bats,” according to a Scientific American article, “can tell the distance of objects with high precision using the time delay between emission and echo, and are able to determine a difference in distance as small as one centimeter.”
Although many humans are afraid of bats because they are believed to carry disease, when it comes to white-nose syndrome, “the irony is that humans are helping to spread it,” Tieche said.
According to the National Park Service, humans can spread the fungus from one hibernating place to another by accidentally carrying the fungus on shoes, clothing or gear.
The Invisible Mammal just completed a successful Seed&Spark crowdfunding campaign, enabling Tieche and her crew to complete principal photography for the film this year. But anyone wishing to help support the project can still donate on the project’s GoFundMe page.
The goal is to complete the film by late 2023, in time to debut it during prime festival season. As Tieche is already an award-winning filmmaker, with her work airing on National Geographic, Smithsonian Channel, Science Channel, Al Jazeera America, PBS, CBS–5 and Fox Worldwide, among other outlets, that goal seems achievable.Tieche hopes the full-length The Invisible Mammal will generate the same kind of response from viewers that the original short did. “People came up to me and said that they now see bats in a whole new light,” she said. “I am hoping, when they see the full-length documentary, they will leave in awe.”