City Nature Challenge
What is the City Nature Challenge?
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.
The 2024 City Nature Challenge will be April 26 – 29. This year there are 691 cities across 51 countries taking part! 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.
How to Participate
Participating in the City Nature Challenge is easy!
- Download the free iNaturalist app and make an account.
- April 26 - April 29, 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).
- Upload your observations to share with the iNaturalist community. They will automatically be added to our San Francisco Bay Area City Nature Challenge project!
- Learn more as your finds get identified!
Bay Area CNC Events 2024
Join upcoming events for the City Nature Challenge 2024 to learn more about our local species, get hands-on help using iNaturalist, and meet other people interested in nature! Click on the links to learn more and to register if needed. All events are in-person unless noted and will be hosted in English unless noted. Be sure to check back as we'll be adding more events!
Pre-CNC events:
- Wednesday, April 17: Virtual (Zoom) 6:30-8:30 pm How to organize a bioblitz & why you should join the City Nature Challenge | Hosted by BioBlitz Club & Keep Coyote Creek Beautiful
- Tuesday, April 23: Virtual (Microsoft Teams) 6:30-8:00 pm iNaturalist Basic Training & Beyond | Hosted by Golden Gate National Parks Conservancy
- Thursday, April 25: San Francisco 2-4 pm Glen Park Branch Library Identify Plants Workshop | Hosted by San Francisco Public Library
Friday, April 26:
- San Francisco 9 am - 12 pm Yerba Buena Island Bioblitz Meet at the Building 1 Lobby | Hosted by TIDA and San Francisco Environment
- Kenwood 9:30-11:30 am Sugarloaf Ridge State Park Nature Hike | Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
- San Francisco 2-4 pm North Beach Branch Library Bioblitz & Identify Plants Workshop | Hosted by San Francisco Public Library
- Kenwood 7:30-9 pm Sugarloaf Ridge State Park Nocturnal Serenades Nature Hike | Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
Saturday, April 27:
- Winters 8 am - 2 pm Stebbins Cold Canyon Reserve Bioblitz | Hosted by the UC Davis Natural Reserve System
- Mountain View 9-11 am Mountain View Shoreline Bioblitz | Hosted by BioBlitz Club & Grassroots Ecology
- Burlingame 9 am - 2 pm Coyote Point Recreation Area Bioblitz| Hosted by San Mateo County Parks
- Martinez 9 am - 2 pm Self-Guided Fernandez Ranch Bioblitz | Hosted by John Muir Land Trust
- San Francisco 10-11:30 am Candlestick Point Bioblitz | Hosted by California State Parks
- Martinez 10 am - 12 pm Guided Pond Stroll Bioblitz at Fernandez Ranch | Hosted by John Muir Land Trust
- San Francisco 10 am - 12 pm Presidio Bioblitz | Hosted by Presidio Trust
- Oakland 10 am - 1 pm Lake Merritt Bioblitz | Hosted by Rotary Nature Center Friends
- Berkeley 10 am - 2 pm UC Berkeley Campus Bioblitz | Hosted by Bay Nature Magazine
- Santa Rosa 10 am - 2 pm Native Bees Field Class | Hosted by Pepperwood
- Tiburon 10 am - 1 pm Ring Mountain Open Space Preserve Bioblitz | Hosted by Golden Gate National Parks Conservancy & Marin County Parks
- El Cerrito 10 am - 1 pm Hillside Natural Area Bioblitz | Hosted by El Cerrito Trail Trekkers
- San Francisco 10 am - 1 pm Sisterhood Gardens Bioblitz *Registration required | Hosted by Sisterhood Gardens
- San Francisco 12-4 pm Children's Garden Bioblitz | Hosted by San Francisco Botanical Garden
- Kenwood 12:30-1:30 pm Sugarloaf Ridge State Park Nature Hike | Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
- San Francsico 1-3pm McAteer Community Farm Bioblitz | Hosted by Foodwise & Enterprise for Youth
- Montara 1-4 pm Rancho Corral de Tierra Bioblitz | Hosted by Golden Gate National Parks Conservancy
- Saratoga 2-4pm West Valley College Bioblitz (part of the CNPS Wildflower Show) | Hosted by BioBlitz Club
Sunday, April 28th:
- Sunol 9-11 am Sunol Wilderness Preserve Wildflower Bioblitz | Hosted by East Bay Regional Parks
- San Jose 9-11:30 am Almaden Quicksilver Park Bioblitz | Hosted by Keep Coyote Creek Beautiful
- Kenwood 9:30-11:30 am Sugarloaf Ridge Wildflower Hike | Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
- San Francisco 9:30-11:30am Heron's Head Park Bioblitz | Hosted by Wild Oyster Project
- San Francisco 9:30 am - 12 pm Pier 94 Wetlands Bioblitz | Hosted by Golden Gate Bird Alliance
- Los Gatos 10 am - 1 pm St. Joseph's Hill Open Space Nature Hike| Hosted by Latino Outdoors SF Bay Area - Event in English & Spanish
- Kenwood 11 am - 1 pm Sugarloaf Ridge State Park Reptile Hike | Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
- San Francisco 11 am - 2 pm Golden Gate Heights Park Bibolitz | Hosted by Nature in the City
- Kenwood 12:30-1:30 pm Sugarloaf Ridge State Park Butterfly Walk| Hosted by Sonoma Ecology Center & Sugarloaf Ridge State Park
Monday, April 29:
- Half Moon Bay 8-11 am Pillar Point Tidepools Bioblitz | Hosted by the California Academy of Sciences
Tuesday, April 30:
- San Jose 6-9 pm Willow Glen Library South Bay ID Party | Hosted by Keep Coyote Creek Beautiful & BioBlitz Club
Special thanks to our partners
From getting the word out to hosting events, the Academy's Bay Area partners make City Nature Challenge the inspiring, empowering, and fun 4-day nature bioblitz that it is—and we are incredibly grateful. Click the links below to learn more about each group.
Bay Nature Magazine | BioBlitz Club | California Native Plant Society | California Native Plant Society Yerba Buena Chapter | California Lichen Society | California State Parks: Candlestick Point SRA | California State Parks: Sugarloaf Ridge SP | East Bay Regional Park District | El Cerrito Trail Trekkers | Enterprise for Youth | Friends of the Urban Forest | Foodwise | Golden Gate Bird Alliance | Golden Gate National Parks Conservancy | Grassroots Ecology | John Muir Land Trust | Keep Coyote Creek Beautiful | Latino Outdoors SF Bay Area | Marin County Parks | Nature in the City | Pepperwood | Presidio Trust | Rotary Nature Center Friends | San Francisco Botanical Garden | San Francisco Environment Department | San Francisco Public Library | San Francisco Unified School District | San Mateo County Parks | Sisterhood Gardens | Solano County Office of Education | Solano Land Trust | Sonoma Ecology Center | Treasure Island Development Authority | Wild Oyster Project
Additional resources
Explore, observe, and document the plants and animals around you—even inside your house!