City Nature Challenge 2026

Join the Santa Ana Zoo and the Santiago Creek ECO Center for the 2026 City Nature Challenge! We need your help to document the amazing biodiversity in Orange County from April 25-28, then identify those observations from April 29-May 4.

What is the City Nature Challenge?

Started in 2016 as a competition between San Francisco and Los Angeles, the City Nature Challenge has grown into an international event, motivating people around the world to document wildlife in and around their cities, using biodiversity recording platforms like iNaturalist. Run by the Community Science teams at the California Academy of Sciences and the Natural History Museum of Los Angeles County, the CNC is an annual four-day global bioblitz at the end of April, where cities are in a collaboration-meets-friendly-competition to see not only what can be accomplished when we all work toward a common goal, but also which city can gather the most observations of nature, find the most species, and engage the most people in the event.  In 2026, 669 cities participated, with over 102,945 people making 3.3 million observations of nature in the four days of the challenge. The 2026 City Nature Challenge (April 24-27) is gearing up to be the biggest one yet!

How can I participate?

Anytime you see or hear wildlife, take a photo or make a sound recording and upload it to iNaturalist. Participate from wherever you are, or join us for an in-person bioblitz:

• Information coming soon