The timbre of the YELLOWTHROAT'S song always makes me think of the Veery — the time and notes differ but a similar organ quality is in the tones.
Eaton attributes their absence from a locality where they had been present in previous years, to destruction of the young and consequently no descendants to rebird the accustomed haunts. Notwithstanding that the Vireos' homes are placed so as to escape many hazards, they are not immune to Cowbirds, Crows and Owls. Mortality is high among these gentle songsters and Eaton's belief holds good with other species as an explanation of their absence.
Eastern North America from Maine thru southern British Provinces to edge of Great Plains; south to Texas and Gulf States.