ML646316974

觀察細節

Flight calls picked up by PUC. Terrible audio but fourth tone is ID'able and spectrogram details help. Surprisingly hard to distinguish by ear from a house sparrow call except for the fourth call. Spec shows a call peaking below 4 kHz -- too low for a house sparrow -- and the thin upward start and thicker descending end, ending lower than the start, consistent with type 3 (ex. https://macaulaylibrary.org/asset/273706751). Similar house sparrow call is a level inverted V (https://macaulaylibrary.org/asset/644647441) or ending slightly higher than the start. Change in loudness hints at movement consistent with a flight call rather than the perched position typical of the similar house sparrow call.