Started in 2016 as a competition between San Francisco and Los Angeles, the City Nature Challenge (CNC) has grown into an international event, motivating people around the world to find and document wildlife in and around their cities, using biodiversity recording apps and 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 urban 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.
Save the date for the 10th anniversary of the City Nature Challenge in 2025: April 25–28! Participating is easy: just use iNaturalist to make and share observations of wild plants and animals in any of the nine Bay Area counties. Be sure to check back here as well for information about City Nature Challenge events happening throughout the Bay Area.