Yellow Warbler Dendroica petechia
Flight call description A trilled "dziit", usually loud and somewhat sweet. Variable in pitch.
Fig.1. New Jersey September 6, 1997 (MO).
Bird in flight.
Similar species Very similar to Blackpoll Warbler with much overlap but averages slightly lower-pitched, louder, and more clearly trilled. See Cerulean and Connecticut Warblers and zeep calls.
Behavior Primarily a nocturnal migrant but engages in redetermined migration and limited resumed migration. Gives flight call regularly while perched and in flight during the day and during nocturnal migration.
Spectrographic description Measured calls (N=33) were 37.1-72.8 (53.7) mS in duration and in the 5.4-9.2 (6.5-8.2) kHz frequency range. The frequency track was single-banded (rarely with a faint second band) and showed a variable slope. It was modulated with 2-5 (3.5) humps with a spacing of 11.2-15 (13.2) mS and a depth of 0.5-1.7 (1.2) kHz. Modulation troughs were u-shaped to v-shaped, and peaks were frequently leaning to the left (though the last hump was often pointed more vertically).