Red-eyed Vireo ©Dana Miller-Blair
September is largely known for being the best time to look for songbird “vagrants,” or lost birds from eastern North America that get mis-oriented in migration and wind up on the west coast. The vagrant excitement started early this month with a RED-EYED VIREO, the first in the county since 2015, at Elk Slough in Clarksburg on 9/3 (ZP, EI, TU). This brought many local birders to the scene, and a “Patagonia Picnic Table Effect” ensued. This term of birding jargon stems from a famous picnic table in southeastern Arizona and refers to a situation where birders converge to chase a rare species and then turn up additional rarities in the process. The result is a variety of rare birds all found in the same small area. On 9/3, a GREEN-TAILED TOWHEE (KD) and a NORTHERN PARULA (ZP, EI) were found along Elk Slough in the midst of the RED-EYED VIREO excitement.
The Putah Creek Riparian Reserve hosted an EASTERN KINGBIRD on 9/7 (LC, MM), which is just the fifth county record. It spent the day perching atop tall snags and eating grapes from creekside vines, much to the delight of dozens of birders who went to see it. The previous EASTERN KINGBIRD in the county was also a one-day-wonder, from early September 2018. A NORTHERN WATERTHRUSH found a little patch of wooded swamp at the Knights Landing fishing access along the Sacramento River beginning 9/9. This odd eastern warbler continued for three days, although it proved to be secretive (JJ). A TENNESSEE WARBLER, the second in the county this fall following one in August, was found along the Sacramento River on 9/14 (CH).
A BLACKPOLL WARBLER was an exciting find on a private stretch of Putah Creek west of Davis on 9/16, the first in the county in three years (AK). Even crazier was that a second vagrant, a CHESTNUT-SIDED WARBLER, was found a few hundred yards away on the same survey (AK)! Finding a vagrant warbler in Yolo County is notable on its own, but two together is almost unheard of. Another CHESTNUT-SIDED WARBLER was observed briefly at Elkhorn Regional Park on 9/26 (JJ).
A beautiful male ROSE-BREASTED GROSBEAK stopped by a Woodland backyard on the morning of 9/26 (PS). To the delight of many local birders, it returned that afternoon and was seen in the yard with permission of thoughtful hosts. Almost all previous ROSE-BREASTED GROSBEAK records have been single-day birds that were not chasable, so this individual was a real treat and a county bird for many. For the first time in five years, Yolo County had an INDIGO BUNTING. A male was found at the Putah Creek Riparian Reserve on 9/28 (LWD, KD), skulking around in the weedy grasses and willows along the creek. Sporting a mottled plumage of electric blue and nonbreeding tan, it was a neat bird to observe.
A PLUMBEOUS VIREO was reported on 9/22 along Pumphouse Road near Clarksburg, where it was seen in a mixed flock that included a HUTTON’S VIREO (AE). Another HUTTON’S VIREO was along Putah Creek west of Davis on 9/23, along with a HAIRY WOODPECKER (ZP, JJ). Both species are quite unusual on the valley floor, with the vireo having become quite difficult to find in the county in recent years. GREEN-TAILED TOWHEES had a strong showing on the valley floor this fall, with five individuals from around the county. In addition to the Elk Slough bird mentioned above, GREEN-TAILED TOWHEES were photographed at Gordon Slough on 9/9 (JJ), Babel Slough on 9/11 (JG), Grasslands Regional Park on 9/18 (ZP, JJ), and the City of Davis Wetlands on 9/22 (JG, SM).
Woodland Wastewater Treatment Plant (WWTP) and the recently-renamed Pacific Flyway Pond had varying water levels and thousands of shorebirds, gulls, ducks, and terns. A LESSER BLACK-BACKED GULL, the first Yolo County record outside of the winter months, was found on 9/1 and continued to be seen intermittently throughout the month (CD). A STILT SANDPIPER, the second in the county this fall after none last year, was seen for all of thirty seconds on 9/11 before disappearing along with the shorebird flock it was found in (ZP, JJ). A juvenile SANDERLING was found on the morning of 9/18 during a rare September storm front (MP), and it was joined by a second individual later that day (KS). Presumably the same birds continued to be reported off and on for at least a week. At sunset on 9/18, an exceptional flock of at least 120 VAUX’S SWIFTS were seen swirling about the sky, riding the winds of an incoming cold front (ZP, JJ). A first-year FRANKLIN’S GULL spent one evening at the Pacific Flyway Pond gull roost on 9/22 (JJ). A late PURPLE MARTIN was seen flying over WWTP on 9/23, now the latest fall record for the county (KS). A juvenile RUFF was photographed at WWTP on 9/28, but disappeared a short while after its discovery (RF). However, it was photographed again the next day in the same location, so it may well still be in the area.
Three BLACK SWIFTS were reported flying over the South Fork Putah Creek Preserve on 9/9 (GS), and another was well-described from the town of Guinda the following day (ES). While they are remarkably rare in the county with fewer than ten prior records, these reports fall within an established migratory period on the Pacific coast and came during a cold front that brought overcast weather and squalls of rain – a weather pattern that has been known to produce BLACK SWIFT sightings in the region. Presumably these birds are migrating at stratospheric altitudes and are brought down to visible range during stormy weather.
While standing atop a rock outcropping near Reiff Road in extreme northwestern Yolo County on 9/27, birders detected a migrant TOWNSEND’S SOLITAIRE (KS, SS), as well as a LAPLAND LONGSPUR (ES, JJ, KS, SS, ZP). These records, while unexpected, seemed to follow an established pattern of songbirds migrating along ridgetops. This was the first TOWNSEND’S SOLITAIRE in the county since 2023, and one just a few September records. The LAPLAND LONGSPUR is especially unusual, although the species has been recorded at other known ridge migration sites in the past. The September date is the earliest ever recorded in Yolo County.
Finally, a LONG-EARED OWL was photographed during a bird survey of the Putah Creek Sinks on 9/29 (ZP). Presumably a migrant, this unexpected owl is the earliest ever recorded in Yolo County, and may be the earliest fall record for the Sacramento Valley. Perhaps it will be a good year for them in the region.
Thanks to the following for their reports:
Amanda Kindel (AK), Andy Engilis (AE), Chris Dong (CD), Cliff Hawley (CH), Drake Stallworth (DS), Elliot Schoenig (ES), Emmett Iverson (EI), Gregg Schwab (GS), Joshua Greenfield (JG), Julian Johnson (JJ), Kirk Swenson (KS), Konshau Duman (KD), Lyann Comrack (LC), Lynette Williams-Duman (LWD), Mark Martucci (MM), Michael Perrone (MP), Pam Starr (PS), Rob Furrow (RF), Sean Smith (SS), Stewart Mayhew (SM), Tom Uslan (TU), Zane Pickus (ZP),
Photos and Audio Recordings:
Red-eyed Vireo: https://ebird.org/checklist/S271369121
Green-tailed Towhee (Elk Slough): https://ebird.org/checklist/S271362516
Northern Parula: https://ebird.org/checklist/S271372165
Eastern Kingbird: https://ebird.org/checklist/S272125702
Northern Waterthrush: https://ebird.org/checklist/S272512263
Rose-breasted Grosbeak: https://ebird.org/checklist/S275685782
Indigo Bunting: https://ebird.org/checklist/S276169952
Green-tailed Towhee (Gordon Slough): https://ebird.org/checklist/S272508694
Lesser Black-backed Gull: https://ebird.org/checklist/S271201373
Stilt Sandpiper: https://ebird.org/checklist/S272812401
Sanderlings: https://ebird.org/checklist/S274129967
Franklin’s Gull: https://ebird.org/checklist/S274991858
Ruff: https://ebird.org/checklist/S276177884
–Zane Pickus