As autumn weekend crowds of birders at Point Reyes, California attest, the state regularly receives thousands of wayward migrating birds each year, representing over a hundred species.The vast majority of these birds are Neotropical migrant passerines whose breeding ranges are in Canada and the eastern United States, and whose primary migration route lies east of the Rocky Mountains. While the trees at the lighthouse may be dotted with Blackpoll Warblers, the rare appearance of a Golden-winged Warbler or a Red-eyed Vireo is sure to draw much greater attention.