Date: 10/8/26 8:28 pm From: Marty Freeland via groups.io <martinf3...> Subject: [pen-bird] Recent notes: Blackburnian, Magnolia, Prairie, etc.
Hi all,
Highlights from the past four days in San Mateo were an excellent peak fall assortment of eastern warblers—Blackburnian, Magnolia, Prairie, Black-and-white, and Palm—plus American Redstart, the county's second Painted Redstart, and the continuing invasion of montane birds including numerous Evening Grosbeaks.
On Monday 10/5, I covered the north coast from Mussel Rock to Montara and then skipped to Pescadero to dip on the Prothonotary Warbler found the previous day by Aidan Sinha. The north coast had no standout birds but had decent migrant numbers (e.g., 6 Yellow Warblers at Calera Ck, 5 Warbling Vireos over the course of the morning, etc.) and two Nashville Warblers were together at the Farallone Willows in Montara. Two Nuttall's Woodpeckers together at Pedro Pt were my first there and may (?) mark the southernmost point on the San Mateo coast where they are truly regular, though they are increasing across the board. Arriving at the Prothonotary spot, Jim Lomax and I encountered a group who had just seen the bird and who said encouraging things like "You'll see it." Of course, that meant that we did not see the bird! But a female-type American Redstart was a short distance downstream of where the Protho had been. Aidan Sinha reported a possible American Redstart here the previous day, presumably the same bird.
On Tuesday 10/6, I intended to bird from Weed Farms to San Gregorio. Weed Farms and Pie Ranch were both active with above-average numbers of Western Meadowlark, as has been my experience elsewhere this season too (but pipits seem to be in low numbers in San Mateo, at least). At Costanoa, a dull Palm Warbler was my first at that site and my first this season. Shortly after seeing the Palm Warbler, I put my binoculars on something moving in a willow and saw a Painted Redstart looking back at me. After recovering from being flabbergasted enough to manage some identifiable photos, I sprinted to Costanoa Lodge to get the word out and then spent the rest of the time I had trying to refind the bird with others. Unfortunately I only saw it once after the initial sighting, with Richard Jeffers but before most chasers arrived. Further details, notes, and photos are on eBird.
On the way back to the east side of the mountains for classes in the afternoon, I dodged construction on Hwy 84 by taking Gazos to Cloverdale to Pescadero Ck Rd to Alpine Rd. The next day, Al DeMartini had Pinyon Jays on Alpine Rd. I did not have any Pinyon Jays, but the continuing concentration of Evening Grosbeaks on upper Gazos Ck was an amazing spectacle. All seemed to be Type 1 from the Pacific Northwest, not the call type breeding in the Sierra Nevada. At a location on Gazos with at least 25–30 Evening Grosbeaks, I also had two female Pheucticus grosbeaks, one Black-headed and the other perhaps a Rose-breasted (and probably the same possible Rosebeak I had here on 9/29), but they were again uncooperative and I was also distracted by the glorious male Evening Grosbeaks, which were much more interesting. But if anyone wants three "grosbeak" species at once (although Evening is of course a finch and is taxonomically distant from Rose-breasted and Black-headed, despite the shared name), this might be your chance...
On Wednesday 10/7, I covered the south-central coast from Pescadero Ck to Pilarcitos Ck. Pescadero Marsh was blanketed in ground fog so I started instead at the Bianchi property, which has a pumpkin patch and other nice agricultural land (accessed with permission, but the pumpkin patch is open to the public from 10–5). A calling Evening Grosbeak was west across Cloverdale Rd from the Bianchi farm. Because of the thick low fog all over the immediate coast, I checked willow patches in eastern Pescadero that I sometimes skip. At the end of Goulson St, a beautiful Blackburnian Warbler was high in the cottonwoods, giving buzzy flight calls like a Yellow Warbler, before working its way down into the Pescadero Ck riparian to feed. Halfway down Goulson a flock in a different patch of riparian had a Black-and-white Warbler. Maybe I should not skip these parts of Pescadero! I was excited to see that a new community park will open on the vacant lot where Cédric Duhalde found a Blue Grosbeak a few years ago, offering more access to that chunk of creek. Two Nashville Warblers were at the Ovenbird spot on the west side of town. This is a really great year for Nashvilles; I think these were my sixth and seventh so far this season in the county, while most years by this date I have had 0–2. Working all the accessible patches on San Gregorio Ck, Tunitas Ck, and their feeder creeks, the only good flocks I located were on Tunitas Ck well upstream. In one of the best flocks along Tunitas, at the dip, there was a nice Magnolia Warbler. The rest of the day was rather slow except for the piece of Pilarcitos Ck near Repetto's pumpkin patch where a waterthrush was a few weeks ago; that spot had a Western Flycatcher, two Yellows, and many other migrants. In general I struggled to find migrants on the immediate coast on this day, with all the concentrations being pretty well inland. All day I had only 5ish Yellows, 1 Western Fly, no Warbling Vireos, no uncommon western migrants besides the Nashvilles in Pescadero and one Black-throated Gray on upper Tunitas, etc.
On Thursday 10/8, I birded from Pillar Point to Miramar in the morning, covering the last chunk of the coast north of Ano that I had not done this week. For the most part it was quite slow. A flock along San Vicente Ck accessed from Ember Ridge had a Warbling Vireo and a Yellow Warbler; another Yellow Warbler was at the Emergency Willows. Checking the East Miramar Willows, a Prairie Warbler was working the low vegetation around the lone alder. This was only my second rarity here, after a Tennessee with Alex Castelein a couple years ago, over about 25–30 checks in fall, so it was especially fun to see. I like constructing routes made largely of stops where you can hope for a vagrant roughly once every 10–20 visits, but including well more than 20 such sites, so on the whole you still end up (on average) with the odds in your favor.
In addition to all the other irruptive movements documented this year, there has been a modest movement of Golden-crowned Kinglets into the lowlands over the last week, including two at Princeton Willows today. Cassin's Finches have reached SF, Santa Clara, and Santa Cruz, and should certainly be gettable along Skyline in San Mateo this week! And southern Oregon and northern Nevada had reports of Blue Jay in the past few days as well.
An awesome week of peak season in an awesome county! Enjoy the last couple weeks of fall!
