The Warbling Vireo rarely arrives in numbers before the first week of may though singing males are occasionally heard as early as the middle of April.  It leaves for the south during the first two weeks of September.

     During migration Warbling Vireos may be found in wooded places in every part of the county but in summer they seem to prefer the bluff regions and neighboring territory.  They are heard singing during the nesting season about Independence, Courtney, Atherton and Sibley and in the Missouri and lower Blue Valleys.  They have been found nesting in Fairmount Park.