Spend a fun day outdoors with a team counting individual birds and species, and contributing to our understanding of bird populations! Both beginners and experienced birders welcome.
About the Christmas Bird Counts
Every December, hundreds of Bay Area birders take part in Golden Gate Audubon’s Christmas Bird Counts (CBCs) in Oakland and San Francisco. From before dawn until dusk, they trek through parks, neighborhoods, and wetlands, venture out in boats on the bay, and skirt reservoirs and bayside mudflats to identify the species and count the numbers of birds at every site.
Our 2020 counts were limited by the Covid-19 pandemic: We regretfully had to cancel the Oakland count and hold a smaller San Francisco count with social distancing protocols. If public health guidelines permit, we look forward to resuming our longstanding count traditions in 2021.
Annual Christmas Bird Counts, sponsored by the National Audubon Society and conducted by volunteers, are held throughout the U.S. and Canada. The counts attempt to record every individual bird encountered within a defined 15-mile diameter — about 177 square miles — during one calendar day. The counts began on December 25, 1900, when a small group of bird lovers led by scientist Frank Chapman posed an alternative to the Christmastime “side hunt,” in which teams competed to see who could shoot the most birds and small mammals. Chapman’s group identified, counted, and recorded all the birds they saw, thus founding one of the world’s first and largest “community science” initiatives. The 2020 season marks the 120th year of Christmas Bird Counts.
CBC data is an invaluable tool for scientists studying bird populations and was one of the key sources of data in National Audubon’s September 2014 report on North American birds and climate change.
Our Oakland and San Francisco counts have ranked among the top 25 nationwide in terms of numbers of species found. In recent years, our Oakland count has had more participants in the field than any other count in the world!
- The Oakland count circle extends from Treasure Island northeast to the San Pablo Reservoir in Contra Costa County, and south to St. Mary’s College in Moraga and the Oakland International Airport. With its wide variety of habitats, the Oakland count typically records more than 170 bird species. View a map of our Oakland count areas. Thank you to volunteer cartographers William Wiskes and Rusty Scalf, who recently digitized the paper maps of our Oakland count!
- The San Francisco count circle includes the north tower of the Golden Gate Bridge and all of San Francisco, and reaches down the peninsula to San Bruno Mountain and the wetlands north of the San Francisco International Airport. Also blessed with a wide variety of habitats, the San Francisco count generally tops 160 species. View a map of our San Francisco count areas.
Each count day typically culminates with a festive dinner where final counts were tallied and stories exchanged about rare bird sightings and locations.
Local CBC data are reviewed and then sent to National Audubon Society, where they provide valuable insight into past and present bird populations and the general health of our environment. Recent and historical CBC results are available on the National Audubon Society’s website.
For a look at what CBCs can tell us about changing Bay Area bird populations, see Bob Lewis’s post on our Golden Gate Birder blog about data from Oakland Christmas Bird Counts.
For past CBC results, please see:
2019 SF CBC Report (preliminary info, blog post)
2014 San Francisco count – blog post
Looking for another count area? For the entire California list, check out Nature Alley.
Some local counts we recommend:
- East Contra Costa County
- Eastern Alameda County
- Contra Costa County
- Pt. Reyes Peninsula