Field Sparrow Spizella pusilla
Flight call description A high, pure-toned, distinctly descending "tseew" or "thsew". Sometimes a shorter, less descending "tseep".
Fig.1. New Jersey November 23, 1997 (MO).
Perched bird.
Similar species Le Conte's Sparrow is higher-pitched, more tinny, and typically longer. See descending seeps.
Behavior Nocturnal migrant. Gives flight call regularly while perched and in flight during the day. Flight calls have been documented uncommonly in nocturnal migration.
Spectrographic description Measured calls (N=13) were 38.8-129.3 (90.5) mS in duration and in the 5.7-11.6 (6.6-9.9) kHz frequency range. The frequency track was single-banded or with a light or partial second band and was evenly descending, often with distinct upward bends at both ends. Some calls showed very fine modulations with a spacing of 4.6-5.8 (5.2) mS between humps.