Blue-winged Warbler Vermivora pinus
Flight call description A rising "szeet" with a fine sibilant buzz. Sometimes a more downward-arched "szzzp".
Fig.1. Texas April 12, 1996 (MO).
Bird in short flight.
Examples Diurnal
Similar species Not known to be separable from Golden-winged Warbler. Yellow-rumped Warbler is similar but lower and usually less buzzy. Prothonotary Warbler is longer and sweeter. See Black-and-white Warbler, Ovenbird, and short rising 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=6) were 53.0-70.2 (64.0) mS in duration and in the 4.6-8.7 (5.7-8.2) kHz frequency range. The frequency track was single or double-banded and rising, sometimes with lower-frequency "tails" at the beginning or end. There was usually a fine modulation throughout the call with 3.6-7.2 (5.8) mS between humps and a depth of 300-860 (600) kHz.