[Posted by Chuck Almdale]

In our continuing mission to post items about the California Bird Atlas project and get as many people as possible interested in and contributing to this project, here’s an announcement from Van Pierszalowski, instigator and director of this 5-year project.

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Hi birders,

I’m happy to report that the inaugural California Bird Atlas Big Weekend (June 4-7, 2026) was a tremendous success! Thank you so much to our partners for organizing 54 (!) field trips and events throughout the state in a single weekend. Special thanks as well to our incredible Regional Coordinators and the broader atlasing community.

Amazingly, 47% of the confirmed breeding codes recorded during Big Weekend represented new confirmations (species breeding in atlas blocks where they hadn’t yet been confirmed). This highlights the strategic approach atlasers took throughout the weekend, focusing their efforts on expanding coverage and documenting breeding evidence where it mattered most. Many atlasers reported using Blockboard to help identify these opportunities.

See a recap of Big Weekend statistics below. For a deeper dive (plus some of our favorite photos from the weekend), check out the News post on the CBA eBird platform.

BIG WEEKEND BY THE NUMBERS

• 4,180 Atlas checklists were submitted
• 1,211 atlasers submitted checklists, including 181 first-time atlasers
• 1,575 blocks received data, including 194 blocks that had not previously received Atlas coverage (see the News post for a map)
• 26,809 breeding codes were submitted, including 6,121 confirmed-level codes
• 308 species received breeding codes, including 226 species with Confirmed-level breeding codes
• 4,865 confirmed breeding “block ticks” (each species in each block = one block tick), including 2,287 new confirmed block ticks

DISCOVERIES

• What appears to be the first confirmed breeding record of Canyon Wren in Solano County was reported by Eric Pilotte at Stebbins Cold Canyon Reserve on June 7. 
• Atlasers added two new species to the Atlas’s list of confirmed breeders: Bufflehead (reported by Sam Eberhard in Lassen County) and Green-winged Teal (reported in three different blocks — two in Plumas County, one in El Dorado County).

We will be organizing CBA Big Weekends every year throughout the Atlas period (2026-2030), and it will be exciting to see how the results evolve from year to year. Thank you again to the incredible birding community, and here’s to another great atlasing weekend starting now.

Happy Atlasing,
Van Pierszalowski

Director, California Bird Atlas
CBA website: www.californiabirdatlas.org
Join the CBA eBird project: www.ebird.org/atlascalifornia