The genus name Sayornis is constructed from the specific part of Charles Lucien Bonaparte's name for Say's phoebe, Muscicapa saya, and Ancient Greek ornis, "bird".

Its lack of an eye ring and wingbars, and its all dark bill distinguish it from other North American tyrant flycatchers, and it pumps its tail up and down like other phoebes when perching on a branch.

It lacks the buff hue usually present on the lighter parts of the eastern phoebe's plumage, and thus has always clearly defined and contrasting wing-bars.

It also does not bob its tail habitually, and appears on the breeding grounds much later though it leaves for winter quarters at about the same time as the eastern phoebe.

[6] The nest is an open cup with a mud base and lined with moss and grass, built in crevice in a rock or man-made site; two to six eggs are laid.

Insects make up a great majority of its summer diet; included are many small wasps, bees, beetles, flies, true bugs, and grasshoppers.

The poem describes phoebes nesting inside a barn on a farm abandoned after the farmhouse burned to the ground.