City Nature Challenge

Which city around the world has the most nature? The City Nature Challenge 2019, happening April 26-29, will help us find out!

After sweeping the first international City Nature Challenge in 2018, can the San Francisco Bay Area hold onto our title for another year??? In 2018, 68 cities motivated more than 17,000 people to upload 431,000 observations of nature to iNaturalist in the four days of the City Nature Challenge (see 2018 results here). In 2019, more than 120 cities on six continents are taking part, asking residents of and visitors to these urban areas to explore nature all around them and document the species they find! Find out more information and see which cities are participating by visiting the official City Nature Challenge website.

Started in 2016 for the first-ever Citizen Science Day, the citizen science teams at Natural History Museum of Los Angeles County and California Academy of Sciences dreamed up the City Nature Challenge as a fun way to capitalize on their home cities’ friendly rivalry and hold a citizen science event around urban biodiversity. The first City Nature Challenge was an eight-day competition between Los Angeles and San Francisco, engaging residents and visitors in documenting nature to better understand urban biodiversity. Over 20,000 observations were made by more than 1000 people in a one-week period, cataloging approximately 1600 species in each location, including new records for both areas. During the 2016 CNC, we heard so much excitement and interest from people in other cities that we decided we couldn’t keep to the fun just to ourselves. In 2017 the City Nature Challenge went national, and in 2018, the CNC became an international event!

Here in the Bay Area, participating 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 26-29, take photos to make observations of wild plants and animals in your backyard, a park, your walk to school or work - anywhere you find nature. Be sure to mark the observation as captive/cultivated if it's not a wild organism! Also check our bioblitz page to see the many events happening around the Bay in support of the City Nature Challenge - feel free to join one or more!

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 April 30-May 5 identification period.

5. Results will be announced on Monday, May 6!


Join iNaturalist

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.