識別
One of the most common and widespread warblers; often the core member of mixed warbler flocks during migration, especially early in spring and late in fall. Two main populations: “Audubon’s” breeds mainly in the mountains of the western U.S. and into British Columbia; “Myrtle” breeds from the eastern U.S. across Canada to Alaska. All plumages show a bright yellow rump and yellow on the sides. Most “Audubon’s” have a yellow throat, but dull immature females can be off-white. “Myrtle” Warblers have a white throat that wraps around below the cheek. Both subspecies breed in coniferous or mixed forests, often near clearings or edges. In migration and winter, found in any woodland or open shrubby area, including coastal dunes, fields, parks, and residential areas. Often sallies out from a conspicuous perch to snatch insects. Also eats berries in the winter. Calls frequently: a flat “check” (Myrtle) or rising “chit” (Audubon’s). Another distinctive sedentary population, surely a separate species, occurs very locally in the highlands of Guatemala: Goldman’s Warbler. Males are strikingly black overall, and show a mostly yellow throat with white corners.