Spectrograms of kent sounds from seven Ivory-billed Woodpecker expeditions show 587 Hertz as a pattern

Although the Ivory-billed Woodpecker is widely considered to be extinct, expeditions led by professional ornithologists have acquired visual, video, and audio evidence since 1968, with increases in data since 2000. Audio evidence for kent sounds (n=150) were examined for commonality; this was found to be true with a pattern at 587 Hz that suggests a morphological basis. Differences from other species were found on spectrograms. The patterns extend to different states and years and reinforces that the species persists.