The male and female Black-throated Blue Warblers were once thought to be two separate species.
Michael Todd
The males sport a stunning midnight blue along the top of the head, back and tail. Their black throats and bright white undersides create a dramatic effect. In contrast, the females are pale olive with buff-colored undersides – hence the confusion to even John James Audubon.
Michael Todd
To identify the female in the field, look for a small square of white near the shoulder area of the wings (also present on the males). No other “confusing” olive warbler has this mark sometimes referred to as a “pocket handkerchief.”
Another birding benefit to searching for the Black-throated Blue Warbler is its habit of foraging low to the ground. They search with more measured intention and are relatively undisturbed by a human presence.
Bird Bits
Fun Facts: One of the two subspecies is found exclusively in the Appalachian Mountains, nesting in mountain laurel and rhododendron. These Black-throated Blue Warbler males have distinctive black streaks on their backs rather than the solid blue of the other subspecies.
Habitat: the understory and lower shrub areas of mature woodlands, parks and gardens during migration
Conservation Note: The population for this species is on the increase (up 163% since 1970!) likely due to the decrease in clearcutting of forests.
ABOUT THIS SERIES:
“Birds of the Blue Ridge” showcases frequently seen and rare birds across the southern Appalachian region. For over three decades, Angela Minor has traveled with binoculars and field guides across the continental U.S., Alaska, the Caribbean, and seven European countries. She is a travel and nature freelance writer for several regional and national print magazines, and also created and authored the state park birding series for Bird Watcher’s Digest.
Read More by Angela Minor: BlueRidgeCountry.com/AngelaMinor