A buzzy, ascending trill ending with an explosive lower note. In the North the Northern Parula is associated with moist boreal forests.
Southern populations prefer wet hardwood forests.
Winters primarily in the West Indies but also found on the mainland in south Florida and Central America. Spring migration may begin as early as mid-February. Typically arrives in late March in the Carolinas, and mid May in their northernmost breeding grounds. Historically, populations of Northern Parula in the Great Lakes region and mid-Atlantic suffered severe declines due to loss of lichens caused by air pollution.