Ruby-crowned KingletRegulus calendula
3 3/4-4 1/2" (10-11 cm). Tiny. Similar to Golden-crowned Kinglet, but greener, with no face pattern except for narrow white eye ring. 2 white wing bars with dark area beyond second. Males have tuft of red feathers on crown, kept concealed unless bird is aroused. Hutton's Vireo is larger, with thicker bill, larger head, and no dark area beyond second wing bar.