Black-throated Sparrow ©Daniel Lee Brown
Recent Reports
October 2026 was a spectacular month for rare birds in Yolo County, headlined by the ongoing montane irruption and a pair of Siberian breeding songbirds that were each observed briefly and not relocated. The irruption brought a host of unusual species from high elevation conifer forests to Yolo County’s portion of the Central Valley and Coast Ranges. The rarest of these were the CLARK’S NUTCRACKERS, which, after being observed flying through the Coast Ranges in late September, made their way to the valley floor in mid-October. One was photographed flying over Slide Hill Park on 10/14 (JG, SSc, KO), one was heard in north Davis on 10/16 (AK) and another was observed briefly on the ground in the El Macero neighborhood on 10/13 (CC).
As early as late September, EVENING GROSBEAKS had reached the valley floor, and their reports only continued to build throughout October, with dozens of reports from Davis. This included many flyovers, typically involving single birds but also occasional groups of up to seven birds. Some landed briefly in tall conifers or ornamental fruit trees in search of food. Up to this point, all EVENING GROSBEAKS that have been audio recorded have been confirmed as “Type 1,” which comes from the Pacific Northwest and has proven to be the primary type involved in the 2026 irruption.
RED CROSSBILLS arrived in the valley a bit later than the grosbeaks, with the first reports in Yolo County on 10/10, flying over North Davis (SH) and Goodnow Slough north of Cache Creek (JG). On 10/11, four were seen near Village Holmes in west Davis (MM). A few days later, one was heard over Slide Hill Park in Davis (ZP), and then three more the next day (KS, JG). Pretty soon, they were everywhere, with over a dozen reports in the final two weeks of October from throughout Davis and Woodland. Like the grosbeaks, many of these were flyovers, but some were seen landing and attempting to forage from various ornamental conifers. Similar to the grosbeaks, some were singles, some were in small groups, and the largest flock reported was a group of nine together at the UC Davis Arboretum on 10/25 (RF, MNC). The majority of the crossbills have been identified as “Type 2,” although a few “Type 4” individuals have been recorded. Recordings are important in determining the call types of the species.
CASSIN’S FINCHES are traditionally the rarest of the irruptive winter finches in the valley, but there were multiple reports in Davis between 10/14 and 10/21. These came from Slide Hill Park (MP, ZP), west Davis (RF, JG), north Davis (BW), and Central Park (JZ). A few additional CASSIN’S FINCHES were reported from the Coast Ranges, including three on Rayhouse Road on 10/2 (TE, MS), two on Reiff Road on 10/10 (JJ, SSm, KS, ZP, BW), and one on County Road 53 near Pierce Canyon Falls on 10/18 (JJ, SSm, KS, ZP).
In addition to all of the CLARK’S NUTCRACKERS, EVENING GROSBEAKS, RED CROSSBILLS, and CASSIN’S FINCHES, there have also been above average numbers of PINE SISKINS, VARIED THRUSHES, and PURPLE FINCHES on the valley floor, with plenty of each reported from throughout the county especially later in the month. It will be interesting to see whether these species continue their presence throughout the winter or begin to thin out over time.
But the montane mayhem was not all the birds had to offer! Easily the rarest bird of the period was photographed on 10/19, a WHITE WAGTAIL at the Woodland Wastewater Treatment Plant (WWTP) (CH). This spectacular Siberian songbird was the first documented Yolo County record. Unfortunately it was not recognized until weeks later when photos were reviewed by the observer, but nonetheless it is a truly incredible record and is one of the rarest birds of the year so far in the county. The October date is consistent with many of the records of WHITE WAGTAIL elsewhere in California, primarily on the coast.
Another mega-rarity was recorded on 10/24 on Merritt Island, south of Clarksburg in the delta. It was a RED-THROATED PIPIT, which flew over a birder giving its diagnostic flight calls (much like the sound of a bike tire rapidly deflating following a puncture) (AE). The calls were fortunately caught in the background of a running video camera by an observer filming a ROCK WREN. What an incredible stroke of luck it is to be already videoing a locally common bird when a bird of such rarity flies overhead! This is just Yolo’s third county record of RED-THROATED PIPIT, and the first documented with media. Like the wagtail, the October date is consistent with the majority of California’s records of the species.
Also of note were three adult COMMON TERNS at WWTP on 10/1 (JB). The report made for the third record of COMMON TERN in the county this fall, totalling six individuals. Those numbers tied the combined total number of records and exceeded the total individuals in the county from the entire previous decade. A flyover HUDSONIAN WHIMBREL at WWTP on 10/23 was unusual for a species that is scarcely reported in fall, and is quite rare after September (ZP).
Winter gull season got off to a strong start with two LESSER BLACK-BACKED GULLS at the Yolo County Central Landfill in the last week of October. A third-cycle was there on 10/26 (PB), and an adult was photographed on 10/29 (HW). The species continues to expand their range throughout North America and an associated increase in Yolo County has been documented. Surely continued coverage of the landfill this winter will produce more of them.
Finally, an adult BLACK-THROATED SPARROW certainly won the month’s avian popularity contest since it arrived at the UC Davis Arboretum (CBK). First discovered on 10/22, it is the ninth Yolo County record, though interestingly the last six have occurred since 2020. It continued through the end of the month, and has been enjoyed by dozens of birders, including many from the Birdwatching Club at UC Davis! The confiding sparrow with a “James Harden beard” has put on a show for many student birders looking to enjoy a rarity between classes and studying. A walk by the sparrow stakeout might see various college students, professors, birders and passers-by, all enjoying the company and the good bird. It’s a nice reminder of the community that birding creates for people of all ages and backgrounds.
Thanks to the following for their reports:
Peyton Bounds, Jacob Bower, Claudia Butler-Kibbey, Carolina Chapman, Todd Easterla, Andrew Engilis Jr., Robert Furrow, Joshua Greenfield, Steve Hampton, Casey Hirsh, Amanda Kindel, Monte Neate-Clegg, Megan Miller, Michael Perrone, Zane Pickus, Mark Sawyer, Samuel Schmidt (SSc), Sean Smith (SSm), Kirk Swenson, Kelli O’Neill, Bart Wickel, Henry Witsken, Joe Zeno
Photos and Audio Recordings:
Clark’s Nutcracker (Slide Hill Park): https://ebird.org/atlascalifornia/checklist/S402332215
Red Crossbill (Slide Hill Park): https://ebird.org/atlascalifornia/checklist/S402586662
Red Crossbill (Davis Cemetery): https://ebird.org/atlascalifornia/checklist/S403157358
Cassin’s Finch (Reiff Road): https://ebird.org/atlascalifornia/checklist/S401159093
Common Terns: https://ebird.org/atlascalifornia/checklist/S398151951
Hudsonian Whimbrel (audio): https://ebird.org/atlascalifornia/checklist/S404842117
Lesser Black-backed Gull (third-cycle): https://ebird.org/checklist/S405722163
White Wagtail: https://ebird.org/checklist/S403886601
Red-throated Pipit: https://ebird.org/checklist/S405499923
Black-throated Sparrow: https://ebird.org/atlascalifornia/checklist/S407343770
–Zane Pickus