California Bird Atlas Big Weekend

June 4-7, 2026

A STATEWIDE EFFORT

California Bird Atlas Big Weekend is a four day statewide celebration of birds and the new California Bird Atlas – featuring dozens of field trips, community events, and a collective mission to document as many species breeding in as many blocks as possible.

GET INVOLVED

  • Submit observations using CBA’s eBird project (join here).

  • Attend an event (see calendar here).

  • Host your own event. Submit details using this form.

WHY ARE WE DOING THIS?

  1. Welcome new atlasers: Just getting started? There are events for all experience levels.

  2. Expand coverage: Already atlasing? Head to under-surveyed blocks to find breeding evidence for missing species.