Vocal Repertoire and Duetting in the Okinawa Rail Rallus okinawae

Abstract

Calls and songs of the Okinawa Rail Rallus okinawae YAMASHINA et MANO were recorded with video camera and tape recorder in "Yanbaru", northern Okinawa Island. Vocalizations were described and analysed by sonograph and wave form; (1) Kyo call (Call I), (2) Gu call (Call II), (3) Krr calls (Solo-song I), (4) Kek duet and (5) Kek call (Solo-song II). Two birds were observed to duet without facing each other. Duetting was initiated by one bird assumed to be a male, while the other followed suit. Vocal calls then occurred either in unison or antiphonally. Each individual exhibited a distinct pattern of varied tones and interval of calls. Solo-song II resembled a duet, but each was distinct in wave form.