September! Most consider this to be the premier birding month of the year, and this year was nothing short of spectacular. It felt as though rare bird reports were coming in nonstop, and Yolo County birders were kept on their toes with a long list of birds to chase.
The stars of September were a pair of particularly rare eastern warblers, or “vagrants.” The first, a BLACKBURNIAN WARBLER, was found on 9/20 at Babel Slough (CT, MM). This bird, presumably a hatch-year, represents just Yolo’s second record following the first two years ago at Putah Creek. While somewhat elusive at times, dedicated birders managed to catch glimpses of this mega-rarity through at least 9/23. On 9/27, a PALM WARBLERwas found at the Yolo Bypass Wildlife Area (BW), becoming the fifth record for Yolo County. This warbler moved throughout a large area of habitat near Parking Lot C at the bypass, making it difficult to chase. A lucky few who tried the morning of the 9/28 got to enjoy this tail-pumping warbler. Unfortunately for many, the bird disappeared on the afternoon of 9/28 and it was not seen again.
Backing up a bit, the month got off to a hot start with a TENNESSEE WARBLER at the Putah Creek Riparian Reserve on 9/3 (SH). It or another was reported two days later (RM), and was enjoyed by birders for another week while it reliably visited a secluded “birdbath” on the edge of the creek. The list of vagrants continued to build on 9/13 when a BLACKPOLL WARBLER was found at Grasslands Regional Park (LG). On 9/16, an AMERICAN REDSTART was found at Babel Slough (LC). Incredibly, birders chasing this redstart discovered a second individual the following day (KD, LW)! This is likely the first time that two AMERICAN REDSTARTS have been seen together in Yolo County. Putah Creek Riparian Reserve joined the AMERICAN REDSTART-party on 9/24 (BD), bringing the tally to three for the fall. Including the end of August, Yolo County has had an incredible total of ten eastern warblers so far this fall! This impressive count is no doubt due in large part to the increase in coverage that many places have received. The lesson? Keep on birding! Unusual sightings can occur anywhere, anytime.
A handful of rare sparrows were discovered in the month of September. Perhaps most exceptional was a “THICK-BILLED” FOX SPARROW (usually a subspecies of montane meadows and high-elevation chaparral) found on the valley floor at Babel Slough on 9/11 (JL, SB). A BREWER’S SPARROW, a drab sparrow of the Great Basin, was reported at Putah Creek Riparian Reserve on 9/22 (MP). Two GREEN-TAILED TOWHEES were discovered during the period, with one at Grasslands Regional Park on 9/13 (FF), and another at Babel Slough on 9/20 (WY, VW).
Other notable birds throughout the period included a SNOWY PLOVER at North Regional Pond found on 9/8 (ZP), and a migrant VESPER SPARROW at the Yolo Bypass Wildlife Area on 9/17 (AB, SP, ZW). Two DUSKY FLYCATCHERSwere reported during the month. One was at Grasslands Regional Park on 9/19 (BW, MP), and another at the Putah Creek Riparian Reserve on 9/24 (MH).
It is also worth mentioning the following noteworthy records of species that are common in Yolo County at certain times of year. While it is an expected species throughout the spring and summer, LESSER NIGHTHAWKS migrate south in the fall and most if not all are gone by the first week of September. One was seen at Capay Open Space Park on 9/25 (KS), and this represents the latest record of the species in Yolo County. On a similar note, a EURASIAN WIGEON seen at the Yolo Bypass Wildlife Area on 9/10 (BW, SS, CT) represents the earliest arrival of the species, breaking the record set last fall of 9/23. It is unclear whether these early and late records are correlated to a change in migration timing or are just a result of people looking out for these easily-missed species. And finally, the CACKLING GOOSE that spent the summer at Woodland WTP and surrounding areas continued throughout the month. It only has a little longer to wait before it can rejoin its migratory relatives when they return here for the winter.
Thanks to the following for their reports:
Adam Burnett (AB), Bart Wickel (BW), Bob Dunn (BD), Cameron Tescher (CT), Frank Fabbro (FF), Jasen Liu (JL), Kirk Swenson (KS), Konshau Duman (KD), Lief Gallagher (LG), Lyann Comrack (LC), Lynette Williams (LW), Matthew Maciosek (MM), Michael Perrone (MP), Roger Muskat (RM), Samuel Bressler (SB), Scott Hoppe (SH), Sean Smith (SS), Sergey Pavlov (SP), Violet Wu (VW), Wentao Yang (WY), Zane Pickus (ZP), Zihan Wei (ZW)
eBird Checklists with photos:
Blackburnian Warbler: https://ebird.org/checklist/S119103550
Palm Warbler: https://ebird.org/checklist/S119545874
Tennessee Warbler: https://ebird.org/checklist/S118516248
American Redstart (Babel Slough #1): https://ebird.org/checklist/S118912214
Vesper Sparrow: https://ebird.org/checklist/S118940023