Call-based identification as a potential tool for monitoring Great Spotted Kiwi

Abstract

The ability to discriminate between individuals on the basis of call features has proven to be a useful tool for monitoring rare, nocturnal and cryptic bird species. In this study, vocal individuality was assessed in a population of Great Spotted Kiwi (Apteryx haastii) in the Hawdon Valley, New Zealand. Acoustic recorders were installed near the nest-sites of seven pairs between November 2012 and March 2013. Recorders were again installed at the new nesting sites for three of these same pairs in the following season (September-December 2013). Temporal and spectral parameters of calls were measured and stepwise discriminant function analysis was used to determine whether these parameters were effective in discriminating between individuals. The analyses indicated that Great Spotted Kiwi vocalisations were highly individualised. Male individuals were classified with an accuracy of 95.7%, on the basis of seven parameters, and females with an accuracy of 90%, on the basis of five call parameters. Individuals could also be accurately identified between years, suggesting that the individual features of calls are temporally stable. These findings suggest that Great Spotted Kiwi vocalisations could be used for acoustic identification purposes.