Laura Erickson's For the Birds

This splendid warbler once had a breeding range concentrated in the Ozark Mountains east through the open woodlands of Tennessee, Kentucky, northern Alabama, and northern Georgia, but in recent decades it’s expanded its range northward into southern New England, southern Ontario, and the southern portions of the Great Lakes states. National Audubon classified it as “climate threatened,” their models predicting that the species may be forced to accelerate its northward expansion because nearly two-thirds of its current breeding range may no longer be suitable by the year 2080. Unfortunately, this northward movement puts it in direct competition with Golden-winged Warblers. The two species hybridize frequently, and over time, the Blue-winged Warbler tends to genetically swamp out the Golden-wing.