Little Stint ©Zane Pickus
The bird of the year thus far in Yolo County was a LITTLE STINT at the Yolo Bypass Wildlife Area (YBWA). The bird was discovered in the evening on 8/22, but it was distant and proved a difficult identification challenge for those lucky enough to be there when it was found. After over an hour of trying for diagnostic looks, excitement grew as it became clear that this faded adult sandpiper was in fact a stint (CD)! Fortunately, dozens of birders were there the next morning, and this Siberian shorebird put on a show! The bird spent much of the next few days in the same drying field, providing wonderful opportunities for photography and close study of relevant field marks (such as the orange wash to the head and wing, dark-centered wing coverts with orange edges, white throat with a dull gray “bib,” two white lines down its back, long wings, and short, tapered bill that was slightly decurved). The stint was last seen on 8/27. This is an incredible find not simply due to its rarity, but also because it was picked out amongst a flock of hundreds of similar WESTERN SANDPIPERS and LEAST SANDPIPERS. This LITTLE STINT is just the second ever observed in Yolo County, with the prior record from July 2011 at the City of Davis Wetlands. LITTLE STINT is a remarkable rarity anywhere in North America, and needless to say it was a “Life Bird” for many who got to see it.
This summer there has been a wealth of habitat at the YBWA, as new management practices led to flooded fallow fields in July and August with shallow water for shorebird habitat. This additional stopover habitat proved critical for migratory shorebirds, with thousands of birds using the habitat daily. A remarkable 26 species of shorebirds and six species of gulls and terns were recorded at the wildlife area in July and August, and there have been many highlights. An adult SANDERLING was observed briefly on the evening of 7/27, a species that is less than annual in the county (JJ). Over ten SEMIPALMATED SANDPIPERS were found, as well as three SOLITARY SANDPIPERS. There were frequent reports of uncommon migrants including SHORT-BILLED DOWITCHER, WILLET, MARBLED GODWIT, BAIRD’S SANDPIPER, and PECTORAL SANDPIPER. Two FRANKLIN’S GULLS were found in August, a juvenile that spent a few days beginning 8/19 (JG), as well as an apparent adult on 8/30 (MH). A beautiful STILT SANDPIPER, the first in the county in two years, was found on 8/30 and enjoyed by a host of birders (ZP).
Waterbird habitat throughout the summer has been plentiful, and an interesting variety of rarities were discovered as a result. Multiple SOLITARY SANDPIPERS were found at Rivergarden Farms near Knights Landing (ES, JJ, ZP), as well as a single bird at the City of Davis Wetlands (JG). Woodland Wastewater Treatment Plant (WWTP) maintained varying water levels throughout the summer, providing habitat for a constant stream of noteworthy birds. A LEAST TERN was photographed on 6/24, although it only stayed for a few minutes before disappearing (JJ, ZP). This is just the eighth Yolo County record, though the late June date is consistent with prior reports from the Central Valley. An adult SEMIPALMATED SANDPIPER on 7/3 is the earliest fall record for the county (JJ, ZP). WWTP hosted two SNOWY PLOVERS, the first on 6/11 (JG) and the other on 7/7 (JG, ZP, JJ). A GLOSSY IBIS was photographed on the afternoon of 7/18 (LC), and a few birders followed-up that evening in order to obtain satisfactory images of this difficult-to-identify species. Pending acceptance by the California Bird Records Committee, this would be the eighth county record of GLOSSY IBIS, and the first since July 2023. Additionally, a COMMON TERN was found and observed by multiple parties at WWTP on 7/31. This migrating adult did not stay long and is one of just a scant few July records for the Central Valley (JG, KD, LWD, MP).
While spring migration got off to a slow start this year, the month of May was jam packed with exciting birds to keep Yolo birders busy throughout the month. Grasslands Regional Park proved yet again that it is the best place to see Empidonax flycatchers in the region. It hosted a GRAY FLYCATCHER on 5/1 (CD) and a DUSKY FLYCATCHER on 5/9 (CD). Additional DUSKY FLYCATCHERS were at Fremont Weir Wildlife Area on 5/18 (JG) and in residential Davis on 5/24 (RF). A Davis backyard had a GRAY FLYCATCHER on 5/19 (KD, LWD). Late migrant CALLIOPE HUMMINGBIRDS were at the UC Davis Arboretum on 5/1 (AD, GP, LWD, MP) two were at Uslan Farms on the same date (TU), and another was in Woodland on 5/15 (BC, KS). ALLEN’S HUMMINGBIRDS returned to Uslan Farms in Clarksburg for the fifth straight year, suggesting a local breeding population somewhere in the area (TU). Unusual on the valley floor, at least four COMMON POORWILLS were found, spanning the dates of 4/30 – 5/21. The YBWA had a couple of May reports of SOLITARY SANDPIPERS, with one on 5/1 (DK, JR, RF, ZP), and another on 5/8 (CD). Two SNOWY PLOVERS were together at the YBWA on 5/3 (EM, JJ, ZP).
On 5/18, a group of birders ventured out to the far northwestern corner of Yolo County near the Lake County line, standing atop a rock outcropping in search of migrating birds. Their dreams came true that morning in the form of a flyby BLACK SWIFT, an extraordinarily difficult bird to find in Yolo County and one of eight or fewer county records (BW, JJ, SSm, ZP). BLACK SWIFTS are known to migrate through the Coast Ranges in late spring, but are also famous for migrating at extremely high altitudes and with the remarkable speed you would expect from a swift. These habits, coupled with the fact that access to lookout points in Yolo County’s sliver of the Coast Ranges are few and far between, make BLACK SWIFT an extremely difficult bird to search for in the county. That being said, some birders do get lucky! A pair of BLACK SWIFTS flew over Audubon Bobcat Ranch on 6/5, and the Yolo Bird Alliance phenology team was ready with cameras to document the moment (JG, JS, JZ, SSh). This was an exciting addition to the phenology survey’s bird list.
When birds are migrating, it pays to look up! That was certainly the case this spring with an interesting collection of rare bird flyover records. Perhaps most unexpected was a group of three FRANKLIN’S GULLS over the UC Davis campus on 5/6 (EM). A rare bird anywhere in the county, spotting a migrating group and being aware enough to recognize the pertinent field marks is a skillful feat. More expected were flyover PURPLE MARTINS in multiple locations. A vocalizing pair flew over north Davis on 5/17 (JJ, ZP), and three individuals were observed over northwestern Yolo County on 5/18 (BW, JJ, SSm, ZP).
Somewhat surprisingly, there were no vagrant songbirds in Yolo County this spring. However, a singing BELL’S VIREO in West Sacramento near Lake Washington on 5/22 is a remarkable record (MS). The BELL’S VIREO was once a common breeder along riparian corridors throughout the Central Valley (such as Putah Creek), but they have unfortunately been extirpated and are now exceptionally rare in Yolo County. The West Sacramento bird was heard and audio recorded for two mornings but, to the dismay of many local birders, it went quiet by midday on 5/23 and was only ever heard by the original observer. Yolo’s most recent documented record of BELL’S VIREO is from 2011, when at least two birds summered in the Putah Creek Sinks.
With many spring migrants running late this year, it makes sense that some continued to pass through Yolo County well into June. However, a few species were found far after they would be expected in the area. This set new late spring dates for a handful of species. Prior to this year, there were zero records of HERMIT WARBLER in Yolo County from the month of June. This year, there were six! The latest was on 6/16 at the Putah Creek Riparian Reserve (ZP). A BLACK-THROATED GRAY WARBLER on 6/1 at Cache Creek Settling Basin was just the third June record for the species (JJ, SSm, ZP). PURPLE FINCH has never been confirmed as a breeding bird in the county, so a report of two singing birds on Rayhouse Road on 5/29 is intriguing (JG). TOWNSEND’S WARBLERS, WILLOW FLYCATCHERS, SWAINSON’S THRUSHES, and other songbird migrants also trended later into the season, but these species are not unexpected as migrant stragglers in the region. A WESTERN SANDPIPER, on the other hand, was a total surprise at the YBWA on 5/31 (JT). It is the first record of the species from late-May or early-June.
As the calendar turns to September, birders throughout the region are eager to see what will be found. Yolo County already had its first songbird vagrant of the season, a TENNESSEE WARBLER at Audubon Bobcat Ranch on 8/28 (JG, SSh). This adds another species to the ever-growing list of birds recorded on the Bobcat Ranch phenology survey. September is typically the best month of birding in our area, as it is the peak of migration and dispersal for many species and a time when rarities can be found at seemingly any time and place. There is no time better to get outside and see what you can find!
Thanks to the following for their reports:
Abby Deen (AD), Bart Wickel (BW), Brent Campos (BC), Chris Dong (CD), Daniel Karp (DK), Elliot Schoenig (ES), Ethan Monk (EM), Gerrit Platenkamp (GP), Jason Riggio (JR), Joo Tan (JT), Joseph Zinkl (JZ), Joshua Greenfield (JG), Julian Johnson (JJ), Justin Saldana (JS), Kristen Sesser (KS), Konshau Duman (KD), Luca Cinus (LC), Lynette Williams Duman (LWD), Mackenzie Hollander (MH), Mark Sawyer (MS), Michael Perrone (MP), Rob Furrow (RF), Sean Smith (SSm), Sonjia Shelly (SSh), Tom Uslan (TU), Zane Pickus (ZP)
Photos and Audio Recordings:
Little Stint: https://ebird.org/checklist/S270756110
Franklin’s Gull (juvenile): https://ebird.org/checklist/S268345544
Franklin’s Gull (adult): https://ebird.org/checklist/S270477194
Stilt Sandpiper: https://ebird.org/checklist/S270517494
Solitary Sandpiper (Rivergarden Farms): https://ebird.org/checklist/S265854104
Solitary Sandpiper (City of Davis Wetlands): https://ebird.org/checklist/S269909246
Least Tern: https://ebird.org/checklist/S253834398
Semipalmated Sandpiper (7/3): https://ebird.org/checklist/S256671597
Snowy Plover (6/11): https://ebird.org/checklist/S249377034
Glossy Ibis: https://ebird.org/checklist/S261723824
Gray Flycatcher (Grasslands Regional Park): https://ebird.org/checklist/S231721247
Dusky Flycatcher (Grasslands Regional Park): https://ebird.org/checklist/S235208774
Calliope Hummingbird (UC Davis Arboretum): https://ebird.org/checklist/S232177592
Black Swift (Northwestern Yolo County): https://ebird.org/checklist/S240035882
Black Swift (Audubon Bobcat Ranch): https://ebird.org/checklist/S247123732
Purple Martin (north Davis): https://ebird.org/checklist/S239265184
Western Sandpiper: https://ebird.org/checklist/S245147604
Tennessee Warbler: https://ebird.org/checklist/S270487874
–Zane Pickus