San Francisco Bay Area City Nature Challenge, April 30 - May 3, 2021

Visit the main City Nature Challenge website to learn more about the event and to see the list of the 400+ cities participating in 2021!

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 app to your mobile device.

2. During April 30 - May 3, take photos to make observations of wild plants and animals in your house, your backyard, a park, your neighborhood - anywhere you find nature and can maintain safe social distancing. Check out this guide for finding nature in and around your home for ideas of where to look for species. Be sure to mark the observation as captive/cultivated if it's not a wild organism!

3. Upload your photos to iNaturalist. They will be automatically added to the San Francisco Bay Area City Nature Challenge project!

4. Learn more as your finds get identified, and feel free to help ID other people's observations, especially during the May 4-9 identification period.

5. Results will be announced on Monday, May 10!

San Francisco Bay Area Events








Be sure to check back here to see more events being held in the Bay Area for the 2021 City Nature Challenge! We will add them as they are confirmed.

Here at the California Academy of Sciences, we're so lucky to get to partner with amazing organizations across the Bay Area for the City Nature Challenge! These partners help us get the word out, hold events, and make the City Nature Challenge the amazing and fun 4-day nature bioblitz that it is. Click the links below to learn more about our incredible partners.

California Native Plant Society | California Lichen Society | Bay Nature | San Francisco Department of the Environment | Nature in the City | Presidio Trust | Golden Gate Audubon Society | California Native Plant Society Yerba Buena Chapter | Sutro Stewards | Golden Gate National Recreation Area | San Mateo County Parks | Sequoia Audubon Society | | East Bay Regional Parks | California Center for Natural History | Community for Lake Merritt | Oakland Zoo | Oakland Museum of California | Wholly H2o | One Tam | Marin Municipal Water District | Marin County Parks | Sonoma Ecology Center | Sonoma County Parks | Pepperwood Preserve | Napa County RCD

How to Participate in CNC in Light of COVID-19

As a participant, it is up to you how much or how little you take part! Do only what feels safe for you & your family. It is imperative that you follow all government regulations and guidelines, though.

Here in the Bay Area, we're not sure yet what we'll be able to do by the end of April. But since we're still allowed to go outside no matter what, let's try to enjoy & document nature in whatever ways we feel we can. Being outside can also help to lower stress levels and increase overall feelings of well-being, so take care of yourselves by being in nature if you're able to. Here are some suggestions, and check out our guide to exploring nature around your home:


- Did you know that there are on average 93 species of arthropods living in houses?

- What can you find in your house? What can you see through your windows?

- Focus on identifications!

- During May 4-9, hold virtual ID parties with your friends!

In Backyards:

- Put up bird feeders or moth lights, or put down cover boards to bring nature to you!

- What are the wild plants growing in your backyard?

- What insects or other creatures are using the cultivated plants in your backyard as habitat or a food source?

Outside of your home and backyard:

- Wear a mask and practice social distancing wherever you go.

- Make observations on your own or with your family in local parks and open spaces.

- Think about making observations along sidewalks, pavements, roads, or in residential areas if local parks are too crowded for social distancing. Always be mindful of traffic.

Stay safe, hang in there, and we can't wait to see what you find - in your houses, in your backyards, along sidewalks, in parks - and know that people all around the world are joining you in documenting nature in whatever way they can during these strange times.


Join iNaturalist

Our bioblitzes are powered by iNaturalist, our in-house, citizen science platform. It's a community-powered website and app that makes it easy to upload and share your observations in the field and to get help from other users with flora and fauna IDs.