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Changes in vocal repertoire of the Hawaiian crow, Corvus hawaiiensis,from past wild to current captive populations

December 30, 2016

For most avian species, social behaviour is critically important for survival and reproductive success. Many social behaviours in birds are culturally transmitted, and as bird populations decline across the globe, important elements of these behaviours may be lost. The Hawaiian crow or 'alalā, Corvus hawaiiensis, is a socially complex avian species that is currently extinct in the wild. As in other oscine passerines, vocalizations in the 'alalā may be culturally transmitted. We compared the vocal repertoire of three of the last four wild 'alalā pairs from the early 1990s to three current captive pairs on the Island of Hawai'i to determine how acoustic behaviour has been affected by changes in their social and physical environment. Over 18 h of recordings from wild breeding pairs were analysed and compared with 44 h from captive breeding pairs. Calls were placed into five putative behavioural categories: (1) alarm, (2) territorial broadcast, (3) aggression, (4) submission and (5) courtship. There was little difference in the overall number and diversity of call types among wild versus captive birds. However, the repertoire was significantly different. Territorial broadcast calls, common components of the wild repertoire, were absent from the captive repertoire. In addition, wild birds had twice the number of alarm calls and had a higher call rate than captive birds. Our results show how socially learned behaviours may change over relatively short periods for an entire species. Understanding how the vocal repertoire and the functional context of vocalizations change may provide useful information for ongoing efforts to reintroduce the 'alalā into the wild.

Publication Year 2017
Title Changes in vocal repertoire of the Hawaiian crow, Corvus hawaiiensis,from past wild to current captive populations
DOI 10.1016/j.anbehav.2016.11.017
Authors Ann M. Tanimoto, Patrick J. Hart, Adam A. Pack, Richard Switzwer, Paul C. Banko, Donna L. Ball, Esther Sebastian-Gonzalez, Lisa Komarczyk, Miyako H. Warrington
Publication Type Article
Publication Subtype Journal Article
Series Title Animal Behaviour
Index ID 70198062
Record Source USGS Publications Warehouse
USGS Organization Pacific Island Ecosystems Research Center