In my previous post about Siberian birds I made a tenuous connection between an above-average season for vagrants in the Bering Sea and a few vagrants farther south and east. Updates from Gambell by Paul Lehman show a continued surge of Siberian birds, highlighted by North America's first Sedge Warbler, and even more of the species recorded earlier in the fall (e.g. a final season's total of ten Little Buntings). Saint Paul Island in the Pribilofs has been just as exciting (updates here and some photos here - but you'll have to search all the way back to Aug 2007), with North America's 2nd or 3rd Grey Heron, another Yellow-browed Warbler (second this fall and fifth for North America), and a remarkable fallout of multiple Eye-browed Thrushes and Grey-streaked Flycatchers, along with Siberian Rubythroats and other species. This fallout also reached Adak 450 miles southwest in the Aleutians and a few birds reached Gambell 450 miles north of St Paul. The total number of Eye-browed thrushes and other species falling out across such a wide area must have been huge.
Back in the lower 48, along with the 3 Arctic Warblers and the Common Rosefinch previously reported, there was an undocumented report of a possible Old World Flycatcher in Monterey, CA on 30 Sep, with one listserv post suggesting that Mugimaki Flycatcher was the leading ID contender. That bird was not relocated and remains unconfirmed, the same as a report of a Brown Shrike near Anchorage AK at about the same time.
I still think it's wise for birders all over North America to familiarize themselves with Eye-browed Thrush, Siberian Rubythroat, Little Bunting, Siberian Accentor, Brown Shrike, and other species so that you will be prepared for the remote possibility that one lands in front of you. But also bear in mind that increasing expectations like this will lead to "false alarms" as Mark Brown describes here, turning an apparent Savannah Sparrow into a possible Lanceolated Warbler- it happens to all of us. But if you're pretty certain you've found something rare, get the word out so other birders can see it, and try to take photos to document it.
The first challenge is finding or noticing the bird: overcoming the natural tendency to pigeon-hole it into an expected species. After that you can worry about confirming your identification.