Dendroica coronata, yellow-rumped warbler, consists of six (or more) subspecies divided into two main groups – the Myrtles, generally more Eastern, and the Audubons, a bird of the Mountain West. These two groups were considered full species until 1973. Yellow-rumped warblers are variable, however, the Myrtles have white throats while the Audubon throat is yellow. Hybridization occurs where the ranges overlap. Even after all these years, Leonard and I still tend to call this bird an Audubon warbler.
Yellow-rumped warbler males are, in my opinion, colorful little birds, particularly in the spring with their bright yellow, white, charcoal grey and black plumage. Female and winter male coloration is duller and generally more brown. The crown and back of a male Audubon’s yellow-rumped warbler are grey streaked with black. There are distinct yellow rump, crown and side patches and the throat is yellow. The wing bars are white.
Yellow-rumped warblers breed in the northern boreal forests, mountain coniferous forests and northern deciduous forests. Short to medium-distance migrators, yellow-rumped warblers winter in the central United States south to Mexico, Central America and the Caribbean. Their preferred winter habitat is more shrubby than summer habitat and may include residential areas. Generally yellow-rumped warblers migrate later in the fall and return to their spring breeding grounds earlier than other warblers.
Insects are the main summer food of yellow-rumped warblers. They will flutter out from trees to catch insects in much the same manner as a flycatcher. Often at a distance I will think Audubon’s warblers are flycatchers. Their winter diet consists of fruits, berries and wild seeds. Yellow-rumped warblers have the ability to digest the waxes in bayberries, enabling them to find winter food further north than other warblers.
The pictured male yellow-rumped warblers were photographed along Ash Creek (Lassen County CA).