Black-and-white Warbler Mniotilta varia
Flight call description A delicate "dzinn" with a fine sibilant buzz, often slightly rising. Many calls have a subtle two-parted character, while others are nearly monotone.
Fig.1. Maryland September 29, 1994 (MO).
Bird in flight.
Similar species Most similar to Blue-winged and Golden-winged Warblers but the subtle two-parted character is usually distinctive. Also compare to Chestnut-sided Warbler.
Behavior Primarily a nocturnal migrant but engages in redetermined migration. Gives flight call regularly while perched and in flight during the day as well as during nocturnal migration.
Spectrographic description Measured calls (N=13) were 56-87.5 (68.3) mS in duration and in the 6.6-10.8 (7.2-9.3) kHz frequency range. The frequency track was single or double-banded, typically with an initial relatively short section of descent followed by a longer variably rising and downward-arched section. It was modulated with a spacing of 3.5-4.1 (3.8) mS between humps and a depth of 0.7-1.2 (1) kHz.