The influence of geographic variation in song dialect on post-translocation pair formation in North Island kokako (Callaeas cinerea wilsoni) | Notornis and Birds New Zealand

摘要

Following the translocation of North Is kokako (Callaeas cinera wilsoni) to Kapiti I, southern North Is, New Zealand, Department of Conservation staff noted that most pairs were forming between individuals that came from the same source origin. This study investigated whether geographic variation in dialects influenced mate selection and, ultimately, pair formation on Kapiti I. Between Nov 1999 and Mar 2001 songs of male kokako that had paired and were resident at a single site were recorded. In addition, recordings were obtained from the Department of Conservation of birds in the source areas. Analysis of the songs indicated that kokako songs were typical of their areas of origin at the time of translocation and differed from songs of birds from different source areas. Translocated female kokako prefentially chose males whose repertoire was typical of the acoustic environment they experienced before translocation. Song analysis and pair formation of kokako born on Kapiti I indicates that the observed assortative mating was a temporary phenonmenon in the years after translocation, which did not continue following juvenile recruitment.