Bird recordings used under Creative Commons license :
Black-Throated Green Warbler
Martin St-Michel , XC185115 Accessible at www . xeno-canto . org / 185115
Cerulean Blue Warbler
Matt Wistrand , XC420724 Accessible at www . xeno-canto . org / 420724
Matt Wistrand , XC368062 Accessible at www . xeno-canto . org / 368062
Baltimore Oriole
Jonathon Jongsma , XC134872 Accessible at www . xeno-canto . org / 134872
Warbling Vireo
Andrew Spencer , XC100053 Accessible at www . xeno-canto . org / 100053