Protecting biodiversity in the Bay Area, California, and beyond is as easy as taking pictures. Take part in the City Nature Challenge between April 24–27, 2026, by joining a bioblitz or observing on your own.
The City Nature Challenge is an annual global urban nature census. We work together with cities all over the world to document the plants, animals, and fungi that live and thrive in and around the places we call home.
The Center for Biodiversity and Community Science (CBCS) at the California Academy of Sciences co-leads the Global City Nature Challenge with the Natural History Museum of Los Angeles County. The CBCS team also leads the California Statewide and San Francisco Bay Area Regional organizing. This webpage serves as a hub for organizers all across California, including the SF Bay Area. For global organizing details, please visit citynaturechallenge.org.
How to Participate
For both budding and veteran community scientists, participation is easy. Photos taken during the Challenge can be uploaded to iNaturalist, where an online community of naturalists confirms species identifications.
Wildlife can be found in the participants’ homes, neighborhoods, backyards or anywhere else, and can be any wild plant, animal, fungi, slime mold or other evidence of life (scat, fur, tracks, shells, etc.). Whether participating in an organized habitat survey or making observations in their own neighborhood, participants can upload photos or sound recordings of their findings to iNaturalist or their city’s chosen platform via app or website where they can learn more about the plants and animals they find as their observations are identified.
Here in the Bay Area, joining in is easy! If you live in or are visiting any of the nine counties that touch San Francisco Bay, all you have to do is:
1. Download the free iNaturalist to your mobile device.
2. April 24–27, 2026, take photos of WILD plants and animals anywhere in the nine Bay Area Counties (San Francisco, San Mateo, Santa Clara, Alameda, Contra Costa, Solano, Napa, Sonoma, Marin).
3. Upload your observations to share with the iNaturalist community. They will automatically be added to our San Francisco Bay Area City Nature Challenge project!
4. Learn more as your finds get identified!
Those not able to take photos or record their observations can still participate by helping identify species documented in their area during and after the Challenge. Many organizers in cities around the world will be hosting wildlife identification events Tuesday, April 29 – Sunday, May 4.
Results will be announced on Wednesday May 13, 2026.
