ML582948651

觀察細節

We entertained the possibility that this bird was a Cassin's Vireo, unlikely to be persistently singing in a ponderosa pine forest east of the Continental Divide in the second week of June. Compare especially the two 30-sec. audio cuts (ML582948871, ML582948871) with those of a nearby Plumbeous Vireo (ML582949171, ML582949221). Also included is some intense chatter from this individual (ML582949141). UPDATE (June 12, 2023): Changing ID to Cassin's Vireo on the basis of acoustic analysis by Ed Pandolfino. Also, I ran the photos by Rick Wright. ADDITIONAL UPDATE (June 17, 2023): According to Ed Pandolfino, the two Plumbeous recordings have phrases in the 2,900-3,000Hz range, right in the heart of Plumbeous. The presumptive Cassin's has phrases in the 3,100-3,300 range, which Ed considers to be intermediate to leaning Cassin's for midpoint pitch range; more relevant, the presence of two-note phrases in the presumptive Cassin's recordings is much more strongly associated with Cassin's than with Plumbeous, although Ed notes that the sample size is not large.