Here are some resources in your area. it probably would be best to turn them over where they can receive the medical attention they may need. It could be you aren't feeding enough or it could be they are sick.
Chicago Bird Collision Monitors
(773) 988-1867
http://www.birdmonitors.net/intro.html
This group can make a referral to a pigeon safe rehabber
Flint Creek Wildlife
Downtown Chicago
(847) 602-0628
http://www.flintcreekwildlife.org
Pigeon friendly
Chicago Bird Collision Monitors
(773) 988-1867
http://www.birdmonitors.net/intro.html
This group can make a referral to a pigeon safe rehabber
Flint Creek Wildlife
Downtown Chicago
(847) 602-0628
http://www.flintcreekwildlife.org
Pigeon friendly