Today (2/3) afternoon Alex Rinkert and I found a Troglodytes giving calls typical of a Winter Wren at the corner of Dearborn Park Rd and Pescadero Creek Rd in San Mateo County. We first heard and eventually saw it in a bottlebrush hedge bordering an orchard on the north side of Dearborn. It was very secretive and called only sparingly, and eventually flew into the vegetation in the creek, where it called a few more times before going silent.
We only saw the bird's face, although it didn't look especially bad for Winter. While the calls should be diagnostic, it proved tough to get a recording, but Alex managed a few. It sounds perhaps a little oddly squeaky in the recordings, but still very unlike a Pacific, and the sonograms reveal discrete harmonic bands, good for Winter. Alex's photos and recordings are on his flickr page: http://www.flickr.com/photos/bdmanzanita/
Hopefully other birders will more thoroughly document this bird.
The obliging male Black-throated Blue Warbler continued in the liquidambar tree and in the creek, when it wasn't being chased off by a Red-breasted Sapsucker.