Sabine’s Gull at the Woodland Wasterwater Treatment Plant ©Zane Pickus
Woodland Wastewater Treatment Plant (WWTP) kept its fall hot streak going with a flurry of rarities in the month of October. Birders were out scouring the ponds starting the first of the month enjoying the RUFF and LESSER BLACK-BACKED GULL that continued from September. On 10/4, the action ramped up with the discovery of a PACIFIC GOLDEN-PLOVER, just the second in the county this year (MM, JG+). A second PACIFIC GOLDEN-PLOVER was found the next day, and both were enjoyed by many over the following weeks (KD, LWD). Meanwhile, as many as 17 PECTORAL SANDPIPERS were an particularly high count of a species that is typically present in lower numbers. Up to three lingering HUDSONIAN WHIMBRELS were late as fall migrants amongst a massive flock of hundreds of LONG-BILLED CURLEWS. Note that the Whimbrel was recently split into two species by the eBird/Clement’s Checklist and the North American form was therefore was renamed with the term “Hudsonian,” although the split has not yet been recognized by all North American taxonomic groups1.
With birders already flocking to Woodland to enjoy the slew of rarities, WWTP had even more in store! On 10/6, a stunning juvenile SABINE’S GULL was found along with a COMMON TERN (BW, ZP, TP). For a moment in time, WWTP had representative species from Siberia, the midwest, the Arctic, and the Pacific Ocean! The SABINE’S GULL hopscotched its way south along the wastewater ponds, visiting with the local AMERICAN AVOCETS, before eventually picking up and riding the gusty north wind out of sight. A 30-minute-wonder, it was the only SABINE’S GULL in the county this year. The COMMON TERN, on the other hand, remained at WWTP for over a week. It shattered the record for the longest-staying individual of the species in Yolo County and became the latest record of COMMON TERN in the county as well.
On 10/16, a migrant GRASSHOPPER SPARROW was found at WWTP (HW). This was the first record at the hotspot of this rare fall migrant. SURF SCOTERS made a strong showing throughout inland-California in mid-October, so it was exciting but not completely surprising when an adult male was found at WWTP on 10/26 (JJ). Unlike most Yolo County scoter records, this bird was not refound the next day but was enjoyed by a few who raced out to see it the evening it was found.
VESPER SPARROW is a very challenging bird to find in Yolo County, as the species has failed to return to traditional wintering locations in the county’s western foothills in recent years. As such, searching for migrant individuals on the valley floor may be the best way to locate the species in the county going forward. A bird amongst SAVANNAH SPARROWS and WHITE-CROWNED SPARROWS along County Road 106 south of Davis was a great find on 10/10 (JJ), and is the first one in the county so far this year. Sticking to sparrows, the second GRASSHOPPER SPARROW of the month was photographed at South Fork Putah Creek Preserve on 10/22 (GP), in the traditional migratory window for the species.
While WWTP held most of the shorebird action this month, a juvenile RUFF spent a couple of days at the Yolo Bypass Wildlife Area beginning 10/25 (CD). This was confirmed to be a different bird from the one at WWTP, as both birds continued to be seen through the end of the month at their respective locations.
A male YELLOW-BELLIED SAPSUCKER frequented a fruiting chinese pistache tree at Slide Hill Park in Davis beginning 10/28 (MP). It stuck around for three days and was photographed by many local birders. A COMMON POORWILL was found deceased on the UC Davis campus on 10/30, though given its condition it may have passed a few days prior. Regardless, it is the latest fall record for the valley floor in the county, and the specimen now resides at the UC Davis Museum of Wildlife and Fish Biology. Also of note were two groups of early MOUNTAIN BLUEBIRDS on 10/19, with one group at Capay Open Space Park and the other in the southern Dunnigan Hills (KS). This is the earliest fall return date for Yolo County and one of just a couple of October records.
A COMMON LOON made for quite the Halloween treat at the Capay Open Space Park quarry pond (ES). It spent much of the time diving but birders managed a few diagnostic photos throughout the day. After six years without a chasable COMMON LOON in the county, Yolo has now had two individuals this year. The Capay Open Space Park quarry pond is a relatively recently discovered birding location that hosts a variety of diving ducks and grebes in winter, and it may well produce additional rarities in the future.
Thanks to the following for their reports:
Bart Wickel, Chris Dong, Elliot Schoenig, Gerrit Platenkamp, Henry Witsken, Joshua Greenfield, Julian Johnson, Konshau Duman, Lynette Williams Duman, Michael Perrone, Mike Mahoney, Tom Pritchard, Zane Pickus
Photos and Audio Recordings:
Pacific Golden-Plovers: https://ebird.org/checklist/S277498273
Sabine’s Gull: https://ebird.org/checklist/S277741481
Common Tern: https://ebird.org/checklist/S277871229
Vesper Sparrow: https://ebird.org/checklist/S278403878
Grasshopper Sparrow (South Fork Putah Creek Preserve): https://ebird.org/checklist/S280848606
Ruff (Yolo Bypass Wildlife Area): https://ebird.org/checklist/S281574863
Yellow-bellied Sapsucker: https://ebird.org/checklist/S281950018
Common Loon: https://ebird.org/checklist/S282245867
References: Retter, Michael L. P. 2025. The 2025 eBird/Clements Update. North American Birds. 77(1).
–Zane Pickus