We're Checking Our Bats For Opening Day, Too

More than just baseball teams check over their bats in preparation for the season.

We do, too.

Recently, our conservation programs specialist Maggie Jones was out surveying a few of the bat maternity colonies installed in the Chicago River system. (Check out the YouTube video of her at Kickapoo Woods in south suburban Riverdale.)

Perched on ten to 12-foot-tall stilts, the colonies look like small windowless, doghouses. Bats enter through slits near the roofline. Painted brown, the colonies are built in areas exposed to the sun so that the shelters heat up in the summer. Each colony has 64 cubic feet of interior space.

Bats “help each other out so you could get up to 2,000 moms and their babies in [a] particular structure,” said Jones.

The bats most often found in the Chicago area, big brown and little brown, are voracious insect eaters. (One half-ounce little brown bat can eat half its body weight in bugs each night.) The likelihood of insects near rivers makes building colonies near waterways ideal.

VIDEO: A Closer Look at One of Our Bat Maternity Colonies

Bats also play a role in plant pollination and seed dispersal. But bats are facing some serious threats, such as invasive plants and lack of available habitat.

Friends installed its first colonies in 2015 in partnership with the Forest Preserves of Cook County and the generosity of an anonymous donor.  Forest Preserve experts helped scout the locations.

Friends of the Chicago River Director Margaret  Frisbie said bats avoid human contact when possible and, because of their diet, “provide an incredible service”: mosquito abatement preferable to spraying chemicals.

Bat Facts:

  • There are some 1,300 bat species worldwide and have evolved over 60 million years.

  • They are the only mammals naturally capable of true and sustained flight.

  • In many languages, the word for "bat" is similar with the word for "mouse" – in German "Fledermaus" means “flutter” and “mouse”. Bats however are not closely related to mice.

  • Click Here To Learn More About Becoming a Friends of the Chicago River Member

  • Most bat moms give birth to a single pup at a time. Baby bats can weigh up to one-third of their mother’s body weight. That would be the same as a female human giving birth to a 40-pound infant.

  • The smallest bat, a Kitti’s hog-nosed bat, weighs less than a penny.

We need volunteer wildlife monitors to visit the sites at least twice a month and report back on what they see. Groups and families are encouraged, though those under 18 must monitor with an adult.  No experience is necessary.

We have some spring training sessions coming up:

Wednesday, April 11, 6:00 p.m. to 8:30 p.m. (includes dinner)
North Park Village Nature Center, 5801 North Pulaski Road, Chicago, IL

Saturday, April 14, 9:15 a.m. to 11:45 a.m. (includes breakfast)?
North Park Village Nature Center, 5801 North Pulaski Road, Chicago, IL

Thursday, May 17, 5:30 p.m. to 8:00 p.m. (includes dinner)
REI – Lincoln Park, 1466 North Halsted St., Chicago, IL

Saturday, May 19, 9:30 a.m. to 12:00 p.m. (includes breakfast)
REI – Lincoln Park, 1466 North Halsted St., Chicago, IL

Please only register for one date, as all sessions contain the same content.

To register, please email our Ecology Outreach Manager Mark Hauser at mhauser@chicagoriver.org or call 312-939-0490 ext. 11