By Ken Burton
On January 1, California eBirders awoke to a brave new world: the start of the California Bird Atlas (CBA) Project. Chances are you’ve heard about this project, and maybe you’re already participating in it. Its five-year mission: to seek out new birdlife and new populations, to boldly go (pardon the split infinitive) where no eBirder has gone before.
Although “breeding” isn’t in the name, this is fundamentally a breeding bird atlas project (designed to document breeding bird distributions), though it will also add greatly to our knowledge of general bird distributions in the state. The project is linked to eBird, and anyone with an eBird account can participate (joining takes just a click of a button).
After some initial skepticism that such a project was necessary in the eBirdocene, I’ve come to realize that eBird itself is an excellent tool for conducting a breeding bird atlas. I have also learned that the vast majority of atlas blocks have no breeding evidence at all in the eBird database. Thus, our knowledge of breeding bird distributions at the state level is based largely on anecdotal evidence, models, and old data. So, I’ve plunged right in, submitting my first list on January 1 and trying to contribute a list every day.
The justification and mechanics of the project are well described on the website, californiabirdatlas.org. Also check out the eBird CBA page, ebird.org/atlascalifornia/home, which has useful and interesting links. Briefly, the state is divided into about 16,500 nine-square-mile blocks that serve as survey units. The eBird atlas checklists are assigned to individual blocks. Participants are asked to add appropriate breeding codes to their checklists as has always been encouraged. In many ways, nothing is different from the normal eBirding experience, but there are a few important caveats, which I’ll get to.
I thought I’d share some tips gleaned from experience and conversations with folks behind the scenes to help people avoid mistakes, improve the quality of the data, and perhaps make the whole thing less intimidating to anyone on the fence. These fall into two broad categories: location and breeding codes.
Tips on Reporting Location
Whereas eBird locations are points, CBA locations are blocks. Every atlas checklist must be restricted to a single atlas block. Once you’ve joined the project and have it toggled on, you can see the block boundaries (along with eBird locations if you’re online) by pressing the location selection button on the app after you start a checklist. An alert will pop up if you’re close to the edge of your block, and another will tell you if you leave the block. For the time being, these alerts are visual only, but if you find you have wandered out of your block, you can edit the track back across the boundary.
Inevitably but inconveniently, many eBird hotspots fall into multiple atlas blocks, and your checklist will be assigned to the block that contains the pin of the location you select, no matter where you were. CBA does not have access to eBird tracks. This means that you may have to choose whether to contribute data to an existing eBird location or to the atlas. Some popular local hotspots divided by block boundaries are V St. Loop, Cal Poly Humboldt, Blue Lake–cottonwoods, Humboldt Bay, Russ Ranch wetlands, Clam Beach, and Jackson Ranch Rd. There are plans to create temporary eBird hotspots for appropriate portions of some heavily birded divided hotspots; in the meantime, you can create your own as personal locations. If you want to contribute data to both an existing eBird location and the atlas, make sure you and the location pin are in the same atlas block.
If you’re near the edge of a block, you may see breeding evidence (such as an Osprey nest) in an adjacent block. The best way to handle this is to leave the breeding code off your list (but include the bird so you have a complete checklist), then submit an incidental list for the adjacent block with the breeding code. It’s critical for breeding codes to be assigned to the blocks where breeding is believed to be taking place.
Tips on Reporting Breeding Codes
The meat of the project, breeding codes are one- and two-character abbreviations appended to species entries in your checklist to report observations of bird behavior indicative of local breeding. They’ve always been there, but now they have added import for us. They fall into four categories: Observed (no breeding evidence) and Possible, Probable, and Confirmed Breeding. Even if you’ve used these codes before, it’s worth reviewing the instructions on using them.
Each species can have only one code per checklist, and it should be the “highest” one, that is, the one that gives the strongest evidence of breeding (the codes are presented in the app menu in order of increasing weight). This means that some valuable evidence could be left out. For example, say you see a male junco feeding fledglings and a female junco carrying nest material on the same outing, a likely scenario with a multi-brooded species. The feeding trumps the nest-building in terms of strength, but I’d be inclined to submit an incidental list, too, with the lower code to document overall nesting phenology.
“Possible” codes are welcome, but the project is requesting only those in the “Probable” and “Confirmed” categories, which makes the task quite manageable. If you don’t add a code, CBA automatically assigns “Observed”. In addition to eBird’s usual “Is this a complete checklist?” question, CBA also asks whether you’ve added all the appropriate Probable and Confirmed codes when submitting an atlas checklist.
Of special interest: The CBA project director has told me that he is particularly interested in this part of the state and especially in seeing how results in Humboldt will compare with those gathered in the 1990s for the Humboldt Breeding Bird Atlas project. So, here’s an opportunity to put your eBirding to even greater use. And if by some chance you’re not even using eBird, this is another good reason to start. RRAS is sponsoring the project, and atlasing is likely to be an element of its field trips over the next few years.
