Abstract: Codas are characteristic acoustic signals that sperm whales produce in social contexts. They consist of a short series of pulses that are repeated several times within a short time interval. The analysis of these codas and their possible group specificity have led some authors to believe that they may also help understand population trends and geographical separation. The use of a consistent tool for their comparison, therefore, appears necessary to confirm these assumptions on a wide scale. Coda classification is currently achieved by clustering codas into different types based on the number of clicks per coda and their normalised inter-pulse intervals. This labelling does not follow a clear protocol, however, making it difficult to compare results from different studies. Therefore, an alternative naming protocol for labelling the normalised coda clusters is suggested. The goal of the protocol is to remove ambiguity and subjectivity from the current naming schemes and to give a systematic approach to labelling the clusters by a characterisation of their rhythm. The protocol is demonstrated on coda vocalisations recorded near the Canary Islands.

Key Words: SPERM WHALE; PHYSETER MACROCEPHALUS; CODAS; CLASSIFICATION; CANARY ISLANDS

Document Type: Research article

DOI: 10.1578/AM.32.3.2006.370

Page Numbers: 370 – 373