Date: 9/19/26 3:06 pm From: Marty Freeland via groups.io <martinf3...> Subject: [pen-bird] Recent notes: Tennessees, Chestnut, and N. Waterthrush
Hi all,
After returning from Japan earlier in the week I spent Thursday, part of Friday morning, and part of Saturday morning birding the San Mateo coast. Highlights included singles of Am. Redstart, Chestnut-sided, and N. Waterthrush, plus two Tennessees. Migrant numbers were lower than expected at this date, with the exception of invading Red-breasted Nuthatches.
On Thursday I birded from Ano Nuevo to Tunitas with Logan Kahle, Cedric Duhalde, and Michael Long. An adult male American Redstart was at Butano Ck, presumably a continuing bird found by Aidan Sinha in late August. Michael Long spotted a Chestnut-sided Warbler in a flock on lower Gazos Ck and we heard a calling grosbeak that sounded very much like Rose-breasted at The Dip. We ran into Andrew Rush who mentioned that he had seen the grosbeak and that it was a male Rose-breasted. Stopping to scan feeding activity close inshore between Pomponio and San Gregorio, we had at least 7–10 Black-vented Shearwaters, part of this species' major northward movement related to exceptionally warm water this year. A couple Western Tanagers were on Tunitas. Across the board passerine migrant numbers were rather low. Warbling Vireos were well represented, unlike most of last fall, but most common migrants and especially Wilson's Warblers were quite sparse. Red-breasted Nuthatches were at virtually every spot.
On Friday I had only a couple hours free to bird in the morning, but migrant numbers were considerably higher. I covered Miramar to central Half Moon Bay, birding Frenchman's Ck, Sweetwood, East Miramar Willows, Hermosa Willows, West Miramar Willows, Kehoe x Pilarcitos Willows, and Chesterfield access to Pilarcitos Ck. A Tennessee Warbler was at the east end of Frenchman's Ck Pk and another was in the East Miramar Willows. A Nashville and a Black-throated Gray Warbler were together in the West Miramar Willows (the Dusky-capped Fly spot). A Nuttall's Woodpecker at Chesterfield was rare on the coast away from Pacifica. Red-breasted Nuthatches were again at every stop and numbers of common migrants were reasonably good too, with 3–5 each of Yellow and Townsend's warblers in most flocks, 1–2 Western Flycatchers and Warbling Vireos also in most flocks, and a couple other scattered western migrants like the Nashville, B-t Gray, a tanager at Sweetwood, a pewee at Hermosa Willows, etc.
On Saturday I started by trying for Clark's Nutcrackers along Skyline. Looking for vantages clear of the fog I set up at an overlook just south of Windy Hill across from Williams Sisters. A bunch of other folks joined, including Chris Hayward, Malia DeFelice, Caitlin Chock, Alvaro Jaramillo, Eli Gross, Liam Murphy, Michael Long, and others. A fair amount of movement was evident, with numbers of Vaux's Swift and Violet-green Swallow, a couple of Yellow-rumped Warblers, a singing Golden-crowned Sparrow, a Hermit Thrush, and flyover Lawrence's Goldfinches. Within an hour Eli spotted a Clark's Nutcracker moving west or southwest along a ridgeline south of our vantage point. After a while longer Caitlin and I went to bird Half Moon Bay and folks at the skywatch spot had an additional nutcracker and a Lewis's Woodpecker. Migrant numbers in southern Half Moon Bay were fairly low again and we only had a couple Red-breasted Nuthatches, but a cooperative Northern Waterthrush was along upper Pilarcitos Ck at the access point behind the lowest produce stand.
The incursion of nutcrackers we are seeing currently is truly phenomenal, with 15ish in Santa Clara/Santa Cruz, 3 in San Mateo, ~30 (?) in SF, 13 in Solano, 3 in Contra Costa, 1 offshore in Mendocino, and counts as high as 1200 in Santa Barbara and further afield. Red-breasted Nuthatch, Evening Grosbeak, Pinyon Jay, interior (nelsoni group) White-breasted Nuthatch, and perhaps other things, are also irrupting to various degrees. The last time Pinyon Jays reached the county was in the 2003 irruption, when David Suddjian had one on a ridge above Butano. That would be the holy grail this year! Details, photos, coordinates etc. are on eBird or will be soon for all these recent birds.
