Atlas Dispatch: March 2026 Rewind
By the numbers:
In March, 2,029 atlasers submitted 23,063 checklists to the project. Atlasers covered 3,603 blocks, logged 25,700 hours, and covered 19,180 miles (that's like traveling the length of California from top to bottom 22x!). Checklists came in from all 58 counties (go Alpine!) and atlasers submitted nearly 111,000 breeding codes, doubling the previous state record.
We're thrilled to announce that now, less than 3 months since launch, more than 3,000 participants have contributed data to the Atlas! For reference, the same milestone took New York's Breeding Bird Atlas nearly three full years to reach. Thank you for being a part of this project!
April Mini-mission #1
Tell someone new about the Atlas.
Share what you personally enjoy about participating, whether it's an excuse to explore an overlooked urban park, a new thing to "list" beyond life or county birds, or simply a reason to slow down and watch birds one by one. Whatever brings you out, help us grow this community.
Reports from the field:
Want to share a sighting? Email us at info@californiabirdatlas.org!
Atlas anywhere
This month, multiple Regional Coordinators have stressed the value of atlasing wherever you happen to be. From Ginger Langdon-Lassagne: "I have had some excellent breeding code sightings at grocery stores, stuck in construction traffic, and I recently spent a lovely morning checking out the rafters of the local farm/garden center." Atlasing in these kinds of places — even when you don't detect any breeding activity — helps us to understand how birds use the whole landscape.
April Mini-mission #2
Atlas somewhere unexpected.
Next time you're out running errands, take a few minutes to submit an Atlas checklist from somewhere that's not a "prime" birding site. Incidental observations are always welcome, but strive to submit a short Atlas checklist that's complete for both species and breeding codes. You may be surprised what you find!
Watch recent arrivals
From Dom Mosur, reporting from the Bay Area and points north: "With the very early spring migration we're experiencing, we are already getting birds like Lazuli Bunting, Western Tanager, and Nashville Warbler - species that don't usually start arriving until the middle of April. I have a feeling this may translate to a very early breeding season, so people shouldn't wait to get out into these habitats, lest we miss some breeding activity." BirdCast Migration Dashboard data for California reflects this, showing how some large early pulses of migrants have seasonal passage counts running ahead of the historical average:
Species interactions
One of the small large joys of atlasing is taking the time to notice how birds are connected to other species. Karen Kreiger captured this perfectly in a stunning series of an industrious Bewick's Wren:
A Bewick's Wren (sp. 1) collecting the fur of a presumed vole (sp. 2) from the scat of a bobcat (sp. 3) to line its nest.
A Lesser Goldfinch (sp. 1) collecting lichen (sp. 2) from the nest of an Anna's Hummingbird (sp. 3).
A House Wren (sp. 1) nesting in a box humans (sp. 2) built to meet the needs of our dogs (sp. 3) 😇.
April Mini-mission #3
Note how species are connected.
Take the time to note how a breeding bird is using or interacting with another species. This could be documenting the species of tree in which you found a nest; the kind of prey being fed to young; or inter-species competition for a nest box. Record what you observe in checklist comments and share with us!
Atlas firsts:
In these early Atlas Dispatches, we’ve been highlighting Atlas-first confirmed breeding observations for each species. At last check on February 28th, 101 species had already been recorded as confirmed breeders. Since then we've collectively added another 56 more! It’s a long list to scroll through, but soon enough statewide “firsts” are going to be few and far between and we will miss these days. So soak it up!
- Common Yellowthroat – Reported carrying nesting material (CN) by Peter Gordon, JoAnn Nothhelfer, Kevin Bergersen, Susan Parnell, Linda Daily, Zehava Purim-Adimor, George Nothhelfer, & Victor Leipzig at Mile Square Regional Park, Fountain Valley, Orange County
“Female was making repeated visits to the ground to the right of a low shrub, picking up dead grass, and carrying it back into the low part of the shrub. We were not able to see a nest, but she would go out of sight in the shrub for few seconds, and return to the ground and pick up more grass and return to the shrub.”
- Tricolored Blackbird – Reported carrying nesting material (CN) by Konshau Duman at San Jacinto Wildlife Area, Riverside County
“There was a female holding a wad of fibers, I think grass or maybe stripped cattail. She was hopping around below two singing males and then flew off, with one male following her.”
- Snowy Plover – Reported at a nest with eggs (NE) by Robert Patton at San Diego Bay NWR--SoCal Saltworks (restricted access), San Diego County
“I had checked scrapes in area on 3/3/26 with no eggs yet; saltworks staff reported a new single egg in one of the scrapes on the road edge early afternoon on 3/4 (1st nest of season); I confirmed still one egg.”
- American Goldfinch – Reported building a nest (NB) by Patti Koger at San Elijo Lagoon--west, San Diego County
- American Kestrel – Reported occupying a nest (ON) by David Garza & Emily Culhane at Inwood Valley, Shasta County
“Male entered nest box chittering. Male and female emerged. Male later delivered food (lizard) to female. While male chased off a red-tailed hawk, the female finished eating the food and was observed entering nest at sunset and did not emerge.”
- Wood Duck – Reported a previously used nest (UN) by Marc Fenner & Jeri Langham at BACKYARD / GRISTMILL AREA, Sacramento County
“Three Wood Duck boxes had eggs though no Wood Ducks were in the boxes. After the female lays all of her eggs, one per day, she occupies the nest throughout the day. Birds were seen flying up the river.”
- American Robin – Reported occupying a nest (ON) by Hallie Daly at Scarpet Peak, San Mateo County
- Black-billed Magpie – Reported building a nest (NB) by Bob Battagin at Leonhardt Ranch--Learning Landscapes site, Plumas County
“A pair building a nest in a Willow thicket.”
- Abert's Towhee – Reported carrying nesting material (CN) by David Barton, Katheryn Barton, Judy Matsuoka, Anonymous eBirder, & julie rush at Sonny Bono Salton Sea NWR--Union Tract / Visitor Center, Imperial County
- Red-whiskered Bulbul – Reported carrying nesting material (CN) by Alex Sauerbrunn at Los Angeles County Arboretum & Botanic Garden, Los Angeles County
“Spotted in a low bush carrying a fine twig.”
- Barn Swallow – Reported building a nest (NB) by Mary Beth Abordo at Clear Lake SP--Campground, Lake County
“Gathering mud from Kelsey Slough. Note rows of fresh mud globs on wall. Birds have nested here for many years.”
- Bell's Sparrow – Reported at a nest with eggs (NE) by Sean Rowe at 93516, Boron US-CA (35.0079,-117.3673), San Bernardino County
“Flushed adult BESP off nest with 4 eggs about 10” off the ground in white bursage (Ambrosia dumosa) while conducting surveys for nearby solar project.”
- Ridgway's Rail – Reported a previously used nest (UN) by Justyn Stahl at Seal Beach NWR (restricted access), Orange County
“The raft was used with nest still intact and old egg shell.”
- Swainson's Hawk – Reported building a nest (NB) by Elias Aristides Elias at Firebaugh NW, Fresno County
- Rock Wren – Reported occupying a nest (ON) by Kelli O'Neill at Anza-Borrego Desert SP--Palm Canyon & Campground, San Diego County
“Observed on adult in rock crevasse protecting probably nest site and deep inside crack with tail facing out.”
- Hooded Oriole – Reported building a nest (NB) by Sarah Burton at Potrero Hill Rec Center, San Francisco County
“Male and female adults in palm with one complete nest actively building another”
- Clark's Nutcracker – Reported carrying nesting material (CN) by Rachel Smith at Mammoth Mountain Ski Resort, Mono County
“One individual carrying pale, medium to large, multi branched twig in its beak. Landed in top of Whitebark pine. Observed from Eagle Express ski lift. You can always be atlas-ing ;)”
- Blue-gray Gnatcatcher – Reported carrying nesting material (CN) by Alicia Di Rado at Hahamongna Watershed Park (formerly Oak Grove Park), Los Angeles County
“Bird was gathering plant fluff and carrying it around.”
- Lawrence's Goldfinch – Reported carrying nesting material (CN) by Elizabeth Olin & Gabriel Olin at Oak Grove Park (Ripon)--excluding city WTP, San Joaquin County
“A pair was on the ground, and the female grabbed fluffy nesting material.”
- Red-crowned Amazon – Reported occupying a nest (ON) by Alex Dopp & Dennise Rodriguez at San Dimas Canyon Park, Los Angeles County
- Lark Sparrow – Reported carrying nesting material (CN) by Alistair Skinner, Michael Moss & Mike Sos at Cañada Larga Rd., Ventura County
“individual picking up twigs and blades of grass on side of road and then flying off into high brush.”
- Black-capped Chickadee – Reported building a nest (NB) by Alexandra Lamb at Humboldt Bay NWR--Salmon Creek Unit, Humboldt County
- Violet-green Swallow – Reported building a nest (NB) by Aubrey Parnay & Dana Parnay at Pinnacles NP--Condor Gulch Trail, San Benito County
- California Quail – Reported carrying nesting material (CN) by Jasmine Kay at Dilley Preserve, Orange County
“Including one pair on the trail ahead of me. The male stayed further ahead, giving smack calls while the female putted around, yanking strands of grass up from the side of the trail every once in a while. Eventually both birds veered off trail and grew silent.”
- Red-breasted Nuthatch – Reported carrying nesting material (CN) by Dale Rubach at Crawford Ln, Nevada County
“Bird picking up part of dead leaf and flying off.”
- Northern Harrier – Reported carrying nesting material (CN) by Hallie Daly at Lindsay slough 27719, Solano County
“Female carrying sticks”
- Long-eared Owl – Reported occupying a nest (ON) in San Diego County
“About 20 feet up ... If it is true that only the female of this species incubates, then its male partner was perched about 10 feet away from her - looking quite large.”
- Greater Roadrunner – Reported carrying nesting material (CN) by Van Pierszalowski at 27500–27598 Woodfall Rd, Santa Clarita US-CA (34.4171,-118.4363), Los Angeles County
“Two adults in dry river bed passing under bridge. One seen carrying a mouthful of nesting material (including what looked like string) upriver.”
- Rufous Hummingbird – Reported carrying nesting material (CN) by Marla Knight at Home, 9908 Sniktaw Lane, Fort Jones, California, US (41.597, -122.992), Siskiyou County
“2 females collecting nesting material”
- White-faced Ibis – Reported building a nest (NB) by Max Leibowitz at San Diego Zoo Safari Park, San Diego County
“A few pairs copulating. One pair working on an incomplete nest (NB) in this tree by Okavango Outpost restaurant.”
- Brown Creeper – Reported building a nest (NB) by William Kirsch & Liam Ehrman at Coggins Park — Unit 12, Shasta County
“One seen taking twig to dead tree snag (likely Douglas fir 16m high). Nest height: 6m. Went to other side and saw some nest material hanging out between bark and trunk. Two BRCR then observed entering and exiting a few more times, they had two different entrances/exits to this spot behind the bark. You would never notice the nest if the birds weren’t entering the break in the bark, very nondescript.”
- Spotted Owl – Reported occupying a nest (ON) in Amador County
- Ruddy Duck – Reported recently fledged young (FL) by Paulette Ache at Borrego Springs--Resort and Country Club, San Diego County
“One duckling with mother.”
- Wilson's Warbler – Reported carrying nesting material (CN) by Peter Gaede at Santa Clara River, SCR3--Restricted Access, Ventura County
“Female carrying material, male guarding.”
- Eared Grebe – Reported building a nest (NB) by Bruce Mast at Lower Klamath Auto Tour Route, Dorris, California, US (41.992, -121.772), Siskiyou County
“Multiple pairs assembling floating mats of reeds”
- California Gull – Reported carrying nesting material (CN) by Howard Friedman at Charleston Slough/Coast Casey Forebay, Santa Clara County
- Mountain Chickadee – Reported carrying nesting material (CN) by Frank Gilliland & Susan Gilliland at Chilao--Visitor Center, Los Angeles County
- Western Flycatcher – Reported carrying nesting material (CN) by Jim Royer at Santa Rosa Creek Trail--Fiscalini Ranch Preserve, San Luis Obispo County
- Nuttall's Woodpecker – Reported carrying food (CF) by Jane Mygatt at Leo Carrillo Ranch Historic Park, San Diego County
“Drumming. Multiple insects in the bill of this female. I am assuming this is to feed young, though if I interpreted incorrectly, please let me know! The Nuttall’s were quite vocal today.”
- Western Kingbird – Reported building a nest (NB) by Barbara Wise at Holy Cross Cemetery, San Diego County
“Building a nest in a eucalyptus tree. One individual passed nesting material to the other which then added it to the nest.”
- Western Warbling Vireo – Reported carrying nesting material (CN) by Elke Glendenning at UC Berkeley--Botanical Gardens, Alameda County
“Clear view of bird singing and collecting lichen in beak then flying to another tree.”
- Ash-throated Flycatcher – Reported building a nest (NB) by Chris McCreedy at Chemehuevi Wash--High Use Plot B, San Bernardino County
“Such a cool nest. checking rocks for SAPH and saw brown flycatcher w material…and it was an ATFL. Such an exceptional nest, way up the rock face, 30-40 m up, with plenty of Parkinsonia florida altsernatives below. Carrying faceful of duff for lining.”
- Black-necked Stilt – Reported at a nest with eggs (NE) by Matt Sadowski at San Diego Bay NWR--SoCal Saltworks (restricted access), San Diego County
“1-egger on 20 loop.”
- Belted Kingfisher – Reported building a nest (NB) by Alexandra Lamb at Mad River Fish Hatchery, Humboldt County
“Occupied? Two kingfishers near southern hole; one flew off, the male entered and stayed for at least three minutes, 40 seconds.”
- American Avocet – Reported occupying a nest (ON) by Chris McCreedy at China Dry Lake (restricted access), San Bernardino County
“At least one and likely two nests, adults in incubating position away from the rest of the others, on alkali islands on the high, dry, crusty portion of the islands. One in particular was distant from the standing/preening/loafing flock, in craggy alkali on the high point of the island. The other was a little closer to the others but still distant and alone. Yet the location for the second was low enough that, while it looked sufficiently high and dry enough to hold a nest, and while the bird looked to be patiently incubating in the heat, I hesitated to use the ON code until I saw the first bird described above.”
- Yellow-headed Blackbird – Reported building a nest (NB) by Joshua Greenfield at Woodland WTP, Yolo County
“Sizable group setting up in the cattails around the north pond, with multiple singing males and at least two females grabbing dried grasses from the bank nearby and disappearing into the middle of the patch of reeds, making trips every few minutes.”
- Turkey Vulture – Reported at a nest with eggs (NE) by Tobias Felbeck at 95973, Chico US-CA 40.00832, -121.88978, Tehama County
“Stumbled onto a north- facing rock overhang at about 1000 ft elevation. Terrain was fairly steep and Rocky, with cow and game trails throughout. One adult TUVU flushed as we approached. Took a quick peek into the opening to see two, fairly large mottled eggs sitting on bare dirt”
- Pigeon Guillemot – Reported carrying nesting material (CN) by Andrew Vernon at Monterey Bay Aquarium (outside only), Monterey County
“One seen flying underneath the aquarium with macroalgae in its mouth. Known nesting colony under the aquarium's back deck.”
- Purple Finch – Reported carrying nesting material (CN) by William Legge at Rodeo Lagoon (including beach and offshore), Marin County
“Plenty of singing, displaying and even a female carrying nesting material (dry grasses) that disappeared into a mature stand of already leafed out riparian willows.”
- Bullock's Oriole – Reported carrying nesting material (CN) by Peter Beck & Christine Beck at Harry Griffen Regional Park, San Diego County
“Female seen collecting and carrying downy fluff from eucalyptus near dry creek over to eucalyptus grove near houses. Multiple males seen, several singing at the same time in this general area.”
- Cassin's Auklet – Reported at a nest with eggs (NE) by Bridger Buck, Ashley Waters, haysie maurer, & Kate Burns at Southeast Farallon Island (Farallon Islands NWR, restricted access), San Francisco County
“First birds incubating eggs in nest boxes.”
- Little Blue Heron – Reported carrying nesting material (CN) by Anonymous eBirder at 1404 Vacation Road, San Diego, California, US (32.775, -117.24), San Diego County
“Flying with sticks to a palm tree and giving the sticks to a second bird in a nest. We saw at least 10 trips.”
- Bell's Vireo – Reported building a nest (NB) by Joshua Mitchell at Rio De Los Angeles State Park, Los Angeles County
“One bird repeatedly carrying nesting material into a Coast Live Oak and singing frequently.”
- Downy Woodpecker – Reported occupying a nest (ON) by Ann Stockert at Pismo SB--Oceano Campground, San Luis Obispo County
“Observed one pair with the female in a nest approximately 12 ft. above and 4 ft. back from the trail. She stayed in the nest for the duration (15 minutes) while we were in the vicinity. The male remained in the area.”
- Sagebrush Sparrow – Reported carrying nesting material (CN) by Mary Clapp at Mono City Neighborhood Path: North, Mono County
“Pair in suitable habitat, one was carrying nesting material”
- Acorn Woodpecker – A nest with young (NY) reported by John Gray in Los Angeles County
“A pair of acorn woodpeckers have visited the same tree hole for over a month. They are now visiting hole poking their heads in looking like feeding and leaving.”
Before you hit “Submit”:
If you haven’t yet, take a moment to review previous Dispatches (here and here) highlighting a few common coding pitfalls:
- Using Carrying Food (CF) for corvids and raptors feeding themselves.
- Using Occupied Nest (ON) for birds merely visiting a probable nest site (N).
- H (In Appropriate Habitat) applied to birds outside of appropriate nesting habitat.
What else is new?
Atlas tools in "Birdathon"
Regional Coordinator Barry Langdon-Lassagne just released a new version of the free iPhone app Birdathon. The app has a button with some useful dedicated tools for atlasing, including an Atlas blocks map that works offline, and the annotated Breeding Codes in an organized fashion. Here’s a short video showing how it works: https://youtu.be/fXbPQHxCo3U
Upcoming events
California Bird Atlas event
Partner event
- April 6th (Monday, 6 - 7 pm) | ESBA Webinar | "Breeding Bird Atlas in the Eastern Sierra": Please join the Eastern Sierra Bird Alliance (ESBA) for a brief overview of the California Bird Atlas project! In this online webinar, ESBA will introduce this new community science project, share how people like you can get involved, and review the protocol so you can start atlasing with confidence. The webinar will be complemented with a field experience on Sunday, April 12th. More info here.
- April 12th (Sunday, 7 am - 12 pm) | ESBA Field Trip, Bishop, CA: Please join the Eastern Sierra Bird Alliance for a breeding bird atlas field experience! In this bird outing, participants will learn how to search for breeding bird behavior and review how to submit your eBird checklists to the CA Bird Atlas Project. ESBA welcomes bird enthusiasts of all experience levels. Leader: Forrest English. More info here.
- April 14th (Tuesday, 6 pm) | MAS Program, Pacific Grove, CA | "Building California's First Statewide Breeding Bird Atlas": The monthly Monterey Audubon Society Program will feature CBA's Van Pierszalowski to give an overview of the Atlas. Meeting at the Hopkins Marine Station, Izzy Abbot Lecture Hall. More info here.
- April 16th (Thursday, 7 pm) | CBA Atlas Town Hall | "Finding Breeding Birds": The next CBA Town Hall will feature CBA Review Coordinator Megan Jankowski. Megan will be offering practical strategies and tips for how to find and document breeding birds. Register via Zoom | Submit a question
- April 19th (Sunday) | SBS Outing, Whiskeytown, CA: Shasta Birding Society will lead a CBA focused bird walk in the Whiskeytown region. Organizers are hoping to get a lot of new folks to join the project as well as help with any confusion around the nuances of breeding codes and hotspots covering multiple blocks. Check here for updates.
Featured media
A small sample of some of the images that have recently caught our eye. Tag your own media with breeding-related behaviors for easier discovery.