bats have a bad reputation, according to owen hejna, an ecologist at the lincoln park zoo in chicago. many people have a “horrible misconception” that bats are good for spreading rabies, sucking blood, and not much else, hejna said.

but the bat tracker community science project, an initiative through the lincoln park zoo’s urban wildlife institute (uwi), seeks to change that.

hejna, a 2024 graduate of loyola university of chicago, is the community science coordinator of uwi’s bat monitoring program. the initiative brings together volunteers in the chicagoland area for a unique citizen science project, while simultaneously educating the public about the benefits of bats.

for instance, according to hejna, bats are not only critical for pollinating crops and reducing nocturnal pests like mosquitos: they are also responsible for saving lots of money in the agricultural industry. by eating pests — such as lepidopterans, or moths — they protect crops, in turn saving an estimated $1 billion in the corn industry alone, according to a stanford university study.

how the bat tracker works

established in 2018, the bat tracker program gathers volunteers for “bat walks” to conduct acoustic monitoring. this monitoring allows uwi to collect data about bat populations and the challenges they face in chicago. the bat walks take place in 25 different locations, including recent expansions to neighborhoods in the south side and the city of evanston.

volunteers walk a roughly hourlong route at their monitoring site, equipped with a backpack, a microphone that picks up ultrasonic noise, and an ipad that receives the data. the technology, called echo meter, is able to identify bat species based on their calls. the team at uwi then uses this information to visualize the activity of bat populations in different regions of the city. in 2024, 7,300 bat calls were recognized over the course of 105 bat walks. 

this mobile monitoring is supplemented by stationary monitoring systems, where ultrasonic recorders are strapped to trees in a forest reserve. for over a week, the recorders collect data from sunset to sunrise each night. the stationary monitoring project mostly takes place at different locations from the bat walks, including natural spaces as far outside of chicago as the palos forest preserves south of the city and preserves near o’hare airport. this “urban-rural gradient” is used to “analyze how bats are using natural areas at different levels of urbanization,” hejna wrote in an email.

helping chicago’s bats thrive

so how is the data put to use? hejna said that the goal of the bat monitoring program is to study how cities can “build up [their] green spaces to better suit urban bat populations.” 

while agricultural benefits don’t necessarily apply to downtown chicago, bats also provide a wealth of advantages in urban spaces, including maintaining urban biodiversity, according to hejna. 

additionally, keeping track of bat populations allows scientists like hejna to monitor the spread of white-nose syndrome, a fungal disease that has been decimating north american bat populations for more than 20 years. the program’s establishment in 2018 was largely in response to the initial detection of white-nose syndrome in illinois.

the community engagement aspect of the program also strives to decrease the stigma around urban bat populations. getting volunteers involved allows people to learn that bats are present (and even prevalent) in chicago, and to understand how to appropriately handle human-wildlife interactions with bats.

the data collected from bat walks can also be used to determine the impacts of some of the “anthropomorphic” characteristics of chicago that bat populations struggle with, such as urban noise, artificial light, and human-wildlife interactions, according to hejna.

in turn, hejna said, this information gives city planners and engineers better insight to inform city planning so that “urban areas can be better planned with wildlife in mind.”