Four closely related North American bird formsthe eastern Myrtle Warbler (ssp coronata), its western counterpart, Audubon's Warbler (ssp group auduboni), the Northwest Mexican Black-fronted Warbler (ssp nigrifrons), and the Guatemalan Goldman's Warbler (ssp goldmani)are periodically lumped as the Yellow-rumped Warbler (Dendroica coronata).
Since 1973, American Ornithological Union has elected to merge these passerine birds as one species. The Myrtle and Audubon's forms were apparently separated by glaciation during the last ice age, and developed distinguishing physical characteristics. When it was shown, however, that they were able to interbreed, they were no longer considered as separate species. The two Middle American subspecies, goldmani and nigrifrons are sedentary and diverged from the northern migratory subspecies in the Pleistocene, and so probably represent separate species.
The Yellow-rumped Warbler breeds from eastern North America west to the Pacific, and southward from there into Western Mexico. "Goldman's" Yellow-rumped Warbler is endemic to the highlands of Guatemala. It is a migratory bird which travels to Central America and the Caribbean for winters. Among warblers it is one of the last to leave North America in the fall, and among the first to return. It is an occasional vagrant to the British Isles and Iceland.
In summers, males of both forms have streaked backs of black on slate blue, white wing patches, a streaked breast, and conspicuous yellow patches on the crown, flank, and rump. Audubon's Warbler also sports a yellow throat patch, while the Myrtle Warbler has a white throat and eye stripe, and a contrasting black cheek patch. Females of both forms are more dull, with brown streaking front and back, but still have noticeable yellow rumps. Goldman's Warbler, of Guatemala, resembles Audubon's but has a white lower border to the yellow throat and otherwise darker plumage; males replace the slate blue of Audubon's with black.
These birds are primarily insectivorous, although when bugs are scarce, the Myrtle Warbler also enjoys eating the wax-myrtle berries which gave it its name. They often flit, flycatcher-like, out from their perches in short loops, in search of insects.
They nest in coniferous and mixed woodlands, and lay 4-5 eggs in a cup-shaped nest.
The Yellow-rumped has a trill-like song of 4-7 syllables and an occasional check or chip call note.
File:Dendroica_coronata.jpg|A leucistic individual
File:Yellow rumped warbler - natures pics.jpg
Database entry includes justification for why this species is of least concern
Yellow-rumped Warbler Species Account - Cornell Lab of Ornithology
Yellow-rumped Warbler Information and Photos - South Dakota Birds and Birding
Yellow-rumped Warbler - Dendroica coronata - USGS Patuxent Bird Identification InfoCenter
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Yellow-rumped Warbler