Yellow-rumped Warbler - Classification

Classification

Since 1973, the American Ornithologists' Union has elected to merge these passerine birds as one species. The Myrtle form was apparently separated from the others by glaciation during the Pleistocene, and the Audubon's form may have originated more recently through hybridization between the Myrtle Warbler and the Mexican nigrifrons form.

Read more about this topic:  Yellow-rumped Warbler