Kentucky Warbler Oporornis formosus
Flight call description A buzzy, sometimes rising "zeet" (note limited sample size: see Discussion).
Fig.1. Texas April 23, 1994 (WRE).
Bird in flight.
Similar species Figures 1-3 appear very similar to Northern Waterthrush but our limited field experience suggests that some birds may give shorter, lower, more evenly buzzy calls. See zeep calls.
Behavior Primarily a nocturnal migrant and in limited redetermined migration. Gives flight call occasionally while perched and in short flights during the day. Presumably calls during nocturnal migration.
Spectrographic description Measured calls (N=1) was 59.3 mS in duration and in the 5.6-7.1 kHz frequency range. The frequency track was single-banded and slightly rising. It was modulated with 6 humps with a spacing of 9.2 mS and a depth that increased from 500-1000 Hz as the call progressed.
Discussion Our diurnal experience with Kentucky Warbler's flight call is limited to recordings of three individuals and a few others heard. Two poor quality recordings on the breeding grounds show fewer and wider modulations than the calls in figures 1-3.