Chicago Ornithological Society promotes the appreciation and conservation of birds throughout the Chicago region.

We welcome anyone interested in birds — whether you are a beginner or an experienced birder, a photographer or a casual learner, or an activist for bird conservation. We have many efforts to support and activities planned year-round.

2024 is the Year of the Peregrine Falcon!

Twenty-five years ago, after a hard fought election campaign with six contenders and 42,000 ballots cast, the Peregrine Falcon was declared the City of Chicago’s official bird. COS is marking this milestone by declaring 2024 The Year of the Peregrine Falcon.

Join us as we celebrate with falcon themed trips, programs, and media all year long and take this opportunity highlight an incredible species with a long and important history in our city.

The Chicago Birder

Our flagship publication comes out quarterly.

LaBagh Woods Project

COS began restoration work in 2015 at LaBagh Woods on Chicago’s North Side. We host regular work days to clear invasive buckthorn and to plant shrubs. After the spring of 2022, we have planted almost 4,000 new native shrubs, with more plantings to come. We hope this healthier habitat attracts and supports more birds.

Calumet Initiative

The Calumet Region on the south side of Chicago was once dominated by wetlands but decades of industrialization have severely damaged the health of this critical ecosystem. More recently, work has begun to restore and revitalize this unique community. COS has joined countless partners to lead the way in restoring the Calumet region to a healthy place for people and wildlife.