Date: 10/1/26 10:17 am From: Marty Freeland via groups.io <martinf3...> Subject: [pen-bird] Recent notes: Prairie, Blackpoll, Magnolia, etc.
Hi all,
Highlights from coverage of the San Mateo coast on Sunday, Tuesday, and Wednesday in peak fall included a great assortment of eastern passerines. There was one each of Prairie, Magnolia, Chestnut-sided, Tennessee, and Blackpoll warblers, plus Northern Parula, plus a Red-eyed Vireo. The inflection points in the Yellow/Townsend's and Swainson's/Hermit ratios both passed between 9/24 and 9/28 or so, about on schedule.
On Sunday 9/27 I started at Ano Nuevo with Chris Henry, Michael Long, Kaiting Huang, and Tino Castillo before birding Santa Cruz for the rest of the day. We had a highish overcast and light NW winds. A Prairie Warbler was at Ano Nuevo in pines not far from the elephant seal entry kiosk, perhaps the first record for Ano other than an old wintering (CBC) record for the flower farm? Although numbers of Yellow Warbler were down by 80% from the previous week, we still had a decent assortment of western migrants, including a female Black-throated Gray Warbler.
(We then spent the next nine hours in Santa Cruz County without any vagrants, because Santa Cruz is not nearly as awesome a county as San Mateo is.)
On Tuesday 9/29 I covered the south coast from Pie Ranch to San Gregorio. It was sunny for most of the day with moderate NW winds becoming quite strong by around 3 pm. A Cackling Goose was with Canadas at the mouth of Gazos Ck in the early morning; it may be an earlyish arrival (folks in HMB had flyover flocks on the same day) or it may be the individual that summered in northern Santa Cruz Co., at Waddell and elsewhere, and that was reported at least once or twice in southern San Mateo. A Red-breasted Sapsucker at Pie Ranch had a very bright whitish bridle and may have had some Red-naped ancestry, but was not (I don't think) an F1 hybrid. On Gazos Ck Rd, a flock around a half-mile up the road had a HY Red-eyed Vireo, the third I have seen this year in the county, and another flock around where last year's Canada Warbler was included a Rose-breasted/Black-headed grosbeak. My views were mostly dorsal and it may have been either, although its maxilla was light pink and in brief looks at the underside it appeared perhaps more consistent with Rose-breasted to me. Checking the bottlebrushes in Pescadero at the junction of Pescadero Ck Rd and Butano Ck Cutoff, I heard a "half a Yellow Warbler chip" (Ethan Monk's apt term for the category of chip like a Yellow, but cleaner and less husky, that a number of eastern warblers fall into) and pished out a male Northern Parula. At Water Lane, a Nashville Warbler was with a large flock. I had Warbling Vireos at 9 spots with a total of at least 16 individuals, perhaps more, and remarkably only one Wilson's Warbler (at the Butano Ck bridge).
On Wednesday 9/30 I birded the central coast from Pescadero Marsh to Montara with light NW wind and clear skies until a low marine layer rolled in around 4 PM. The ardeid show at North Pond in Pescadero Marsh continues to be impressive, with 30+ Great Egrets and 20+ each of Great Blue Herons and Snowy Egrets. Seems like a great setup for San Mateo's first Tricolored Heron or similar! A Nashville Warbler was at the dip on Tunitas Creek Road. Stopping at various creek accesses (Church St, Johnston St, Main St, Mariners Church, Oak Ave, etc) in Half Moon Bay around noon, I found a large flock behind the Mariners Church and had Magnolia and Chestnut-sided warblers in the flock in quick succession. A double-vagrant flock is always an awesome experience and this one was especially so, as I had gone the whole morning of arguably the very peak date of fall without a vagrant and these were my first good birds at this patch after a year or so of checks. At Sweetwood CG, a Tennessee Warbler was high in the Eucalyptus. Checking Princeton Willows as low afternoon fog was rolling in, I could not locate any flocks but heard another eastern-type chip and tracked down the calling bird, which was a bright Blackpoll Warbler, for excellent views. I think that puts the county at 3 Blackpolls to 4 Blackburnians so far this fall. At the Farallone Willows in Montara, there was another Nashville Warbler. This species is also having a strong showing this fall on the coast. I had only 6 Warbling Vireos on this day and had 3 Wilson's Warblers. Numbers of Orange-crowned Warbler and Western Flycatcher were very strong on both days.
Details, coordinates, photos, etc., are on eBird as always.
