Pine Warbler Dendroica pinus
Flight call description A high, soft, descending "tsee" or "tsu", often with a hollow quality.
Fig.1. Maryland September 12, 1994 (MO).
Bird in flight.
Examples Diurnal
Similar species Similar to Prairie Warbler but typically buzzier and more descending. Similar to Cape May Warbler but lower, softer, and more pure-toned. See Northern Parula, Yellow-throated Warbler, and descending seeps.
Behavior Primarily a nocturnal migrant but engages in redetermined migration. Gives flight call regularly while perched and in flight during the day, and presumably during nocturnal migration.
Spectrographic description Measured calls (N=9) were 39.9-51.1 (44.5) mS in duration and in the 4.8-8.5 (5.9-7.5) kHz frequency range. The frequency track was single-banded, descending, and often with a short downward-arched bend at the beginning. There were fine modulations, sometimes restricted to the second half of the call, with a spacing of 4.7-6.2 (5.5) mS between humps and a depth of 200-300 Hz.