presumed White-breasted Nuthatch nocturnal flight calls
Fig. 4. New York September 15, 2020
Nocturnal flight call sequences (from irruption of Sep-Oct 2020):
1. Danby NY, September 15, 2020 (WRE). Individual calling in nocturnal migration at 0215. Spectrogram of call sequence shown in Fig. 4 above.