COS is excited to once again be a co-organizer of the Chicago area team in this year’s City Nature Challenge!

From April 24 through April 27, 2026, hundreds of cities worldwide will participate in a friendly competition in search and celebration of urban wildlife. The City Nature Challenge (CNC) aims to engage city residents and visitors in learning about their local nature and to help all of us better understand the biodiversity of cities. All skill and experience levels are encouraged to take part on their own, participate in an event, or even organize a bioblitz.

For more information about the challenge, using iNaturalist, and how to participate or organize your own event, visit: https://www.chicagowilderness.org/page/CityNatureChallenge

COS events part of the City Nature Challenge: (coming soon)