Learning to Love Bats

Bats, those frights of vampire lore, neglected attics, and Halloween antics, have taken on a new role in Chicago: charismatic mini fauna.

“It’s a great way for people to connect with wildlife in cities” said Liza Lehrer, assistant director of the Urban Wildlife Institute at the Lincoln Park Zoo, which studies city wildlife and promotes tolerance of biodiversity. The UWI is one of a clutch of conservation organizations in Chicago dedicated to rehabilitating the bat’s dark reputation.

Every night at dusk during the warm months, Chicago’s bats can be spotted throughout the city’s parks and neighborhoods as they emerge in search of mosquitoes and other insects. Because they’re so easy to see, Lehrer said, bats are more relatable from a conservation perspective.

The UWI also aims to prevent human-animal conflicts and to minimize disease transmission, which, in the case of bats would be rabies (rare in the state of Illinois). They also champion bats as useful insect predators, seed disseminators, and sometimes pollinators. In 2018, UWI convinced the city of Chicago to name the little brown bat, which is indigenous to the area, as its official city mammal.

Acoustic monitoring equipment installed by the Urban Wildlife Institute | Photo courtesy of the Urban Wildlife Institute

The Urban Wildlife Institute began monitoring bat activity in the city in 2013. What they found surprised them. They’d expected to find only a few species. Instead, the institute’s 25 acoustic monitoring sites have recorded eight so far—not just in forest preserves but in city parks, golf courses, and cemeteries.

Bats seem to like Chicago. A two-decade study carried out by the Forest Preserve District of Cook County, found higher bat numbers near the city than in the surrounding countryside. “The monoculture of agriculture produces very little food for bats,” said Chris Anchor, a biologist who runs the wildlife division of the forest preserve. Bats also appreciate Chicago’s architecture, which, Anchor said, features “a wide mix of horizontal and vertical structures bats utilize for finding food sources and loafing between feeding.”

Bat housing | Photo courtesy of the Urban Wildlife Institute

Over the past two decades, bat fans have built more than 100 bat boxes on Chicago’s forest preserve land in the hopes of bolstering the local bat population. But the kinds of bats that might use them—the kind that roost in colonies, like the little brown bat and the big brown bat—are on the decline, according to the forest preserve. White-nose syndrome, which was discovered in the state in 2013, may play a role.

Meanwhile solitary bats like red bats and hoary bats are on the rise, a surprise revealed by monitoring the animals using telemetry, a technology that picks up their sounds inflight. Solitary bats seem to echo the psyche of Chicagoans in winter. “When they hibernate, red bats hibernate on the ground under oak leaf litter,” Anchor said. “On slopes or in heavy oak forests, they’ll go to ground and spend the winter there.”

Friends of the Chicago River built six bat condos on 12-foot stilts in sunny-but-out-of-the-way riverside areas between 2014 and 2018. “They feed on insects, and insect life cycles include time on the water,” said Maggie Jones, conservation programs specialist at Friends of the Chicago River. Encouraging these batty predators, she added, is good for the overall health of the ecosystem.

Bats, however, are finicky home shoppers. It usually takes three to five years after a bat house is built for an occupant to move in, and some may never catch a bat’s fancy. Acoustic monitoring has identified five species of bats near the condos, but to date, none of the waterfront dwellings have been occupied.

“I don’t know how to put the real estate sign out for bats to see,” said Jones. “We know they’re here and hope to be able to provide means for them to thrive in perpetuity.”