Photographer Evie Williams caught this Yellow-rumped Warbler (Setophaga coronata) in the park in late March. Affectionately known as “butterbutt” in birding circles, this widespread songbird male shows yellow also on its shoulders and its throat, as Evie’s photographs display so nicely. The yellow throat marks this individual as a male belonging to the “Audubon” form, the numerically largest variety and the most common in the West. The next most numerous, the “myrtle,” has a white throat patch and tends to congregate more on the East Coast. Females wear less showy garb. These birds are found throughout the United States plus Canada and Central America. They are quite capable of breeding in our local climate, being more cold-hardy than other warbler species, but are more likely to be seen here on migration farther north. Their continent-wide success is largely due to their adaptable digestive systems. They thrive on insects by preference but do quite well with berries and seeds, and are the only warblers that can eat the waxy coating of many berries. They may live for seven years in the wild.
According to the Wikipedia writers, there is dispute in bird governance circles about classifying the warbler varieties. The American Ornithologists’ Union considers the Audubon and myrtle forms as one species. The International IOC World Bird List 10.2 disagrees and classifies them as separate species.