A bird the size of a large lime has made the San Mateo County coast the center of the West Coast birding world this week.
The find
SFGate reports that Stanford student Marty Freeland spotted a small warbler darting through a willow near Moss Beach. It had a torpedo-shaped body and a pale stripe over the eye, which he recognized as the mark of an Old World warbler. It turned out to be a yellow-browed warbler. The species breeds in the boreal forests of Siberia and normally winters in Southeast Asia. This one likely flew more than 5,000 miles in the wrong direction.
It's the first confirmed yellow-browed warbler ever recorded in the Bay Area. SFGate says it's only the second confirmed in the Lower 48. On Oct. 22, birders traded reports and directions on the statewide CALBIRDS email list under the subject "Putative YELLOW-BROWED WARBLER." Freeland was among them.
The rush
Once word got out, hundreds of birders made the trip, according to SFGate, some driving overnight from Southern California, Sacramento, Reno and Oregon. Fall migration is when rare birds turn up on the coast. Most are strays from eastern North America, but now and then one arrives from Eurasia, likely crossing the Bering Strait and coming down the wrong side of the Pacific. Seeing one is "the holy grail for birders on the West Coast," one birder told SFGate.
If you go
Vagrant birds often move on within a day or two. Check recent eBird reports before you go, stay on public roads and trails, and respect private property and residents in the neighborhood.