Common summer residents across the southern, central and northeastern U.S., blue-gray gnatcatchers are often overlooked for several reasons. These small, slender insectivores usually feed high in the tree canopy, where they flit about in pursuit of their quarry; even when they descend to lower branches or hunt through shrubs and thickets, their extremely active feeding style makes them difficult to observe.
Experienced birders recognize them by their distinctive shape and rapid movements, often catching sight of their twitching tail with its white outer feathers. Should they stop for a second or two, one might also see their white eye ring and blue-gray back; their thin bill and cocked tail (similar to wrens) also aid identification. But, of all the small insectivores, including warblers, kinglets, flycatchers and wrens, these gnatcatchers are perhaps the most energetic feeders.
Arriving in the Midwest by late April, blue-gray gnatcatchers build a cup-shaped nest on a horizontal branch, often high in the tree. They use soft plant material and spider silk to line the nest and, like hummingbirds, adorn its surface with flakes of lichen. By late September, most have departed for the Gulf Coast or Central America, staying ahead of the autumn chill that might destroy their prey.