Date: 5/18/26 6:35 pm From: Samuel Bressler via groups.io <pacificgoldenplover...> Subject: Re: [OrangeCountyBirding] Update - California Bird Atlas Update, Big Weekend, and Orange County Statistics
Hi Dawn:
I'm sorry you had this negative experience. The Atlas runs similarly to ebird proper in how it handles rare or unexpected events. Much as how recording a vagrant species in ebird requires careful documentation (whether in the form of photographs, audio, and/or comprehensive written description), recording unexpected breeding activity (whether out-of-range, out-of-season, or out-of-habitat), requires similar documentation. This sort of QA/QC is essential for maintaining the integrity of the data that will be used for further analysis at the end of the atlas period. Unlike for regular vagrants/high counts on ebird, there are no automatic filters catching these sorts of things, nor are there dedicated reviewers confirming the observations before they enter the data pool. The process is far more ad hoc at this stage.
Regarding gull breeding behavior, while several gulls are known to breed in grasslands (e.g. Franklin's gull), to my knowledge western gull is not one of these species. I just checked the San Diego County bird atlas, which states "Cliff ledges and predator-free islands were the Western Gull's primitive nesting sites. Increasingly, the gulls are now augmenting these with man-made structures, on which they build a rough nest of debris." The atlas map for this species shows breeding activity around San Diego Bay and La Jolla, but not further south. So it's fair to say that a Western Gull nesting in a grassland in the Tijuana Estuary would be unexpected.
None of this is to say that your observation was incorrect; nesting behavior does indeed change over time. And an expected byproduct of conducting a statewide atlas will be documentation of unexpected breeding behavior. It's just that documenting unexpected breeding activity is going to need to meet a higher bar than establishing expected breeding activity.
To the broader community, I strongly, strongly, encourage birders of all skill levels to contribute to the atlas. While the review process is necessarily slower and more ad hoc, it will be five years before a full dataset will be ready for analysis and publication, giving the small but growing review team plenty of time to go through the observations. For less experienced birders and atlasers, taking photos and detailed notes whenever you observe a new nesting species/behavior will be incredibly useful for anyone reviewing your data. And the very real value incurred by recording dozens or hundreds of "expected" breeding species, the Nuttall's woodpeckers, bushtits, Anna's hummingbirds, house finches, Cassin's kingbirds etc. will more than make up for any honest field errors.
For those interested in beefing up their natural history knowledge in preparation for the atlas, I highly, highly recommend Sylvia Gallagher's Orange County Breeding Bird Atlas. This volume was published based on data collected during the 1980s, and includes detailed descriptions of nesting behavior, habitat phenology, along with maps showing breeding abundance and distribution across the county. Obviously Orange County's breeding avifauna has changed a lot in the ensuing decades (goodbye Loggerhead Shrike and Tricolored Blackbird, hello Vermilion Flycatcher and lowland Dark-eyed Junco!) However, a lot hasn't changed; in particular nest placement, microhabitat, and behavior changes a lot more slowly than range. My old copy was falling apart, so I just bought a new one at the Audubon house for ten or fifteen dollars.
Hope this helps, and please reach out if you have any questions or concerns about the atlas. I won't be able to address all of them, but can at least point you in the right directions
Good birding (and atlasing!)
Samuel Bressler
Brea
Regional Coordinator, California Bird Atlas
