Ethereal song rings through breeding grounds in northern spruce forest; found in thickets and forest understory during migration, when it tends to be shy and hard to find. To distinguish from other Catharus thrushes, note very faint eyering and plain gray face. Small bill with yellow base. Grayer face than Swainson's Thrush and lacks buffy eyering. Nearly identical to Bicknell's Thrush, which shows slight reddish wash to plumage. Song is a stuttering series of descending phrases with a notably wiry tone. Call a high-pitched, piercing "pzeeer."