The Silky-Tailed Nightjar and Other Neotropical Caprimulgids: Unraveling Some Mysteries

The Silky-tailed Nightjar, Caprimulgus sericocaudatus, is identified by song from Yarinacocha, Ucayali, Peru, and from Misiones Province, Argentina. Two caprimulgids of Yucatan, Mexico and adjacent areas, C. badius and Nyctiphrynus yucatanicus, are shown to have almost certainly had their songs confused with each other by field ornithologists. By transposing their songs, the songs of each species then more closely resemble the songs of their presumed close relatives. Thus, the ree-o-ree song of C. badius closely resembles the song of C. sericocaudatus and the will song of N. yucatanicus resembles the songs of N. mcleodii and N. ocellatus. The chip-willow song of C. salvini is shown in a sonogram to be a temporally condensed version (with similar frequency modulation) of the song of C. badius and C. sericocaudatus, its presumed close relatives. It is hypothesized that the ree-o-ree song is primitive and the chip-willow song derived.